Who Benefited from the Aisuru and Kimwolf Botnets?

Our first story of 2026 revealed how a destructive new botnet called Kimwolf has infected more than two million devices by mass-compromising a vast number of unofficial Android TV streaming boxes. Today, we’ll dig through digital clues left behind by the hackers, network operators and services that appear to have benefitted from Kimwolf’s spread.

On Dec. 17, 2025, the Chinese security firm XLab published a deep dive on Kimwolf, which forces infected devices to participate in distributed denial-of-service (DDoS) attacks and to relay abusive and malicious Internet traffic for so-called “residential proxy” services.

The software that turns one’s device into a residential proxy is often quietly bundled with mobile apps and games. Kimwolf specifically targeted residential proxy software that is factory installed on more than a thousand different models of unsanctioned Android TV streaming devices. Very quickly, the residential proxy’s Internet address starts funneling traffic that is linked to ad fraud, account takeover attempts and mass content scraping.

The XLab report explained its researchers found “definitive evidence” that the same cybercriminal actors and infrastructure were used to deploy both Kimwolf and the Aisuru botnet — an earlier version of Kimwolf that also enslaved devices for use in DDoS attacks and proxy services.

XLab said it suspected since October that Kimwolf and Aisuru had the same author(s) and operators, based in part on shared code changes over time. But it said those suspicions were confirmed on December 8 when it witnessed both botnet strains being distributed by the same Internet address at 93.95.112[.]59.

RESI RACK

Public records show the Internet address range flagged by XLab is assigned to Lehi, Utah-based Resi Rack LLC. Resi Rack’s website bills the company as a “Premium Game Server Hosting Provider.” Meanwhile, Resi Rack’s ads on the Internet moneymaking forum BlackHatWorld refer to it as a “Premium Residential Proxy Hosting and Proxy Software Solutions Company.”

Resi Rack co-founder Cassidy Hales told KrebsOnSecurity his company received a notification on December 10 about Kimwolf using their network “that detailed what was being done by one of our customers leasing our servers.”

“When we received this email we took care of this issue immediately,” Hales wrote in response to an email requesting comment. “This is something we are very disappointed is now associated with our name and this was not the intention of our company whatsoever.”

The Resi Rack Internet address cited by XLab on December 8 came onto KrebsOnSecurity’s radar more than two weeks before that. Benjamin Brundage is founder of Synthient, a startup that tracks proxy services. In late October 2025, Brundage shared that the people selling various proxy services which benefitted from the Aisuru and Kimwolf botnets were doing so at a new Discord server called resi[.]to.

When KrebsOnSecurity joined the resi[.]to Discord channel in late October as a silent lurker, the server had fewer than 150 members, including “Shox” — the nickname used by Resi Rack’s co-founder Mr. Hales — and his business partner “Linus,” who did not respond to requests for comment.

Other members of the resi[.]to Discord channel would periodically post new IP addresses that were responsible for proxying traffic over the Kimwolf botnet. As the screenshot from resi[.]to above shows, that Resi Rack Internet address flagged by XLab was used by Kimwolf to direct proxy traffic as far back as November 24, if not earlier. All told, Synthient said it tracked at least seven static Resi Rack IP addresses connected to Kimwolf proxy infrastructure between October and December 2025.

Neither of Resi Rack’s co-owners responded to follow-up questions. Both have been active in selling proxy services via Discord for nearly two years. According to a review of Discord messages indexed by the cyber intelligence firm Flashpoint, Shox and Linus spent much of 2024 selling static “ISP proxies” by routing various Internet address blocks at major U.S. Internet service providers.

In February 2025, AT&T announced that effective July 31, 2025, it would no longer originate routes for network blocks that are not owned and managed by AT&T (other major ISPs have since made similar moves). Less than a month later, Shox and Linus told customers they would soon cease offering static ISP proxies as a result of these policy changes.

DORT & SNOW

The stated owner of the resi[.]to Discord server went by the abbreviated username “D.” That initial appears to be short for the hacker handle “Dort,” a name that was invoked frequently throughout these Discord chats.

This “Dort” nickname came up in KrebsOnSecurity’s recent conversations with “Forky,” a Brazilian man who acknowledged being involved in the marketing of the Aisuru botnet at its inception in late 2024. But Forky vehemently denied having anything to do with a series of massive and record-smashing DDoS attacks in the latter half of 2025 that were blamed on Aisuru, saying the botnet by that point had been taken over by rivals.

Forky asserts that Dort is a resident of Canada and one of at least two individuals currently in control of the Aisuru/Kimwolf botnet. The other individual Forky named as an Aisuru/Kimwolf botmaster goes by the nickname “Snow.”

On January 2 — just hours after our story on Kimwolf was published — the historical chat records on resi[.]to were erased without warning and replaced by a profanity-laced message for Synthient’s founder. Minutes after that, the entire server disappeared.

Later that same day, several of the more active members of the now-defunct resi[.]to Discord server moved to a Telegram channel where they posted Brundage’s personal information, and generally complained about being unable to find reliable “bulletproof” hosting for their botnet.

Hilariously, a user by the name “Richard Remington” briefly appeared in the group’s Telegram server to post a crude “Happy New Year” sketch that claims Dort and Snow are now in control of 3.5 million devices infected by Aisuru and/or Kimwolf. Richard Remington’s Telegram account has since been deleted, but it previously stated its owner operates a website that caters to DDoS-for-hire or “stresser” services seeking to test their firepower.

BYTECONNECT, PLAINPROXIES, AND 3XK TECH

Reports from both Synthient and XLab found that Kimwolf was used to deploy programs that turned infected systems into Internet traffic relays for multiple residential proxy services. Among those was a component that installed a software development kit (SDK) called ByteConnect, which is distributed by a provider known as Plainproxies.

ByteConnect says it specializes in “monetizing apps ethically and free,” while Plainproxies advertises the ability to provide content scraping companies with “unlimited” proxy pools. However, Synthient said that upon connecting to ByteConnect’s SDK they instead observed a mass influx of credential-stuffing attacks targeting email servers and popular online websites.

A search on LinkedIn finds the CEO of Plainproxies is Friedrich Kraft, whose resume says he is co-founder of ByteConnect Ltd. Public Internet routing records show Mr. Kraft also operates a hosting firm in Germany called 3XK Tech GmbH. Mr. Kraft did not respond to repeated requests for an interview.

In July 2025, Cloudflare reported that 3XK Tech (a.k.a. Drei-K-Tech) had become the Internet’s largest source of application-layer DDoS attacks. In November 2025, the security firm GreyNoise Intelligence found that Internet addresses on 3XK Tech were responsible for roughly three-quarters of the Internet scanning being done at the time for a newly discovered and critical vulnerability in security products made by Palo Alto Networks.

LinkedIn has a profile for another Plainproxies employee, Julia Levi, who is listed as co-founder of ByteConnect. Ms. Levi did not respond to requests for comment. Her resume says she previously worked for two major proxy providers: Netnut Proxy Network, and Bright Data.

Synthient likewise said Plainproxies ignored their outreach, noting that the Byteconnect SDK continues to remain active on devices compromised by Kimwolf.

MASKIFY

Synthient’s January 2 report said another proxy provider heavily involved in the sale of Kimwolf proxies was Maskify, which currently advertises on multiple cybercrime forums that it has more than six million residential Internet addresses for rent.

Maskify prices its service at a rate of 30 cents per gigabyte of data relayed through their proxies. According to Synthient, that price range is insanely low and is far cheaper than any other proxy provider in business today.

“Synthient’s Research Team received screenshots from other proxy providers showing key Kimwolf actors attempting to offload proxy bandwidth in exchange for upfront cash,” the Synthient report noted. “This approach likely helped fuel early development, with associated members spending earnings on infrastructure and outsourced development tasks. Please note that resellers know precisely what they are selling; proxies at these prices are not ethically sourced.”

Maskify did not respond to requests for comment.

BOTMASTERS LASH OUT

Hours after our first Kimwolf story was published last week, the resi[.]to Discord server vanished, Synthient’s website was hit with a DDoS attack, and the Kimwolf botmasters took to doxing Brundage via their botnet.

The harassing messages appeared as text records uploaded to the Ethereum Name Service (ENS), a distributed system for supporting smart contracts deployed on the Ethereum blockchain. As documented by XLab, in mid-December the Kimwolf operators upgraded their infrastructure and began using ENS to better withstand the near-constant takedown efforts targeting the botnet’s control servers.

By telling infected systems to seek out the Kimwolf control servers via ENS, even if the servers that the botmasters use to control the botnet are taken down the attacker only needs to update the ENS text record to reflect the new Internet address of the control server, and the infected devices will immediately know where to look for further instructions.

“This channel itself relies on the decentralized nature of blockchain, unregulated by Ethereum or other blockchain operators, and cannot be blocked,” XLab wrote.

The text records included in Kimwolf’s ENS instructions can also feature short messages, such as those that carried Brundage’s personal information. Other ENS text records associated with Kimwolf offered some sage advice: “If flagged, we encourage the TV box to be destroyed.”

Both Synthient and XLabs say Kimwolf targets a vast number of Android TV streaming box models, all of which have zero security protections, and many of which ship with proxy malware built in. Generally speaking, if you can send a data packet to one of these devices you can also seize administrative control over it.

If you own a TV box that matches one of these model names and/or numbers, please just rip it out of your network. If you encounter one of these devices on the network of a family member or friend, send them a link to this story (or to our January 2 story on Kimwolf) and explain that it’s not worth the potential hassle and harm created by keeping them plugged in.

The Kimwolf Botnet is Stalking Your Local Network

The story you are reading is a series of scoops nestled inside a far more urgent Internet-wide security advisory. The vulnerability at issue has been exploited for months already, and it’s time for a broader awareness of the threat. The short version is that everything you thought you knew about the security of the internal network behind your Internet router probably is now dangerously out of date.

The past few months have witnessed the explosive growth of a new botnet dubbed Kimwolf, which experts say has infected more than 2 million devices globally. The Kimwolf malware forces compromised systems to relay malicious and abusive Internet traffic — such as ad fraud, account takeover attempts and mass content scraping — and participate in crippling distributed denial-of-service (DDoS) attacks capable of knocking nearly any website offline for days at a time.

More important than Kimwolf’s staggering size, however, is the diabolical method it uses to spread so quickly: By effectively tunneling back through various “residential proxy” networks and into the local networks of the proxy endpoints, and by further infecting devices that are hidden behind the assumed protection of the user’s firewall and Internet router.

Residential proxy networks are sold as a way for customers to anonymize and localize their Web traffic to a specific region, and the biggest of these services allow customers to route their traffic through devices in virtually any country or city around the globe.

The malware that turns an end-user’s Internet connection into a proxy node is often bundled with dodgy mobile apps and games. These residential proxy programs also are commonly installed via unofficial Android TV boxes sold by third-party merchants on popular e-commerce sites like Amazon, BestBuy, Newegg, and Walmart.

These TV boxes range in price from $40 to $400, are marketed under a dizzying range of no-name brands and model numbers, and frequently are advertised as a way to stream certain types of subscription video content for free. But there’s a hidden cost to this transaction: As we’ll explore in a moment, these TV boxes make up a considerable chunk of the estimated two million systems currently infected with Kimwolf.

Kimwolf also is quite good at infecting a range of Internet-connected digital photo frames that likewise are abundant at major e-commerce websites. In November 2025, researchers from Quokka published a report (PDF) detailing serious security issues in Android-based digital picture frames running the Uhale app — including Amazon’s bestselling digital frame as of March 2025.

There are two major security problems with these photo frames and unofficial Android TV boxes. The first is that a considerable percentage of them come with malware pre-installed, or else require the user to download an unofficial Android App Store and malware in order to use the device for its stated purpose (video content piracy). The most typical of these uninvited guests are small programs that turn the device into a residential proxy node that is resold to others.

The second big security nightmare with these photo frames and unsanctioned Android TV boxes is that they rely on a handful of Internet-connected microcomputer boards that have no discernible security or authentication requirements built-in. In other words, if you are on the same network as one or more of these devices, you can likely compromise them simultaneously by issuing a single command across the network.

THERE’S NO PLACE LIKE 127.0.0.1

The combination of these two security realities came to the fore in October 2025, when an undergraduate computer science student at the Rochester Institute of Technology began closely tracking Kimwolf’s growth, and interacting directly with its apparent creators on a daily basis.

Benjamin Brundage is the 22-year-old founder of the security firm Synthient, a startup that helps companies detect proxy networks and learn how those networks are being abused. Conducting much of his research into Kimwolf while studying for final exams, Brundage told KrebsOnSecurity in late October 2025 he suspected Kimwolf was a new Android-based variant of Aisuru, a botnet that was incorrectly blamed for a number of record-smashing DDoS attacks last fall.

Brundage says Kimwolf grew rapidly by abusing a glaring vulnerability in many of the world’s largest residential proxy services. The crux of the weakness, he explained, was that these proxy services weren’t doing enough to prevent their customers from forwarding requests to internal servers of the individual proxy endpoints.

Most proxy services take basic steps to prevent their paying customers from “going upstream” into the local network of proxy endpoints, by explicitly denying requests for local addresses specified in RFC-1918, including the well-known Network Address Translation (NAT) ranges 10.0.0.0/8, 192.168.0.0/16, and 172.16.0.0/12. These ranges allow multiple devices in a private network to access the Internet using a single public IP address, and if you run any kind of home or office network, your internal address space operates within one or more of these NAT ranges.

However, Brundage discovered that the people operating Kimwolf had figured out how to talk directly to devices on the internal networks of millions of residential proxy endpoints, simply by changing their Domain Name System (DNS) settings to match those in the RFC-1918 address ranges.

“It is possible to circumvent existing domain restrictions by using DNS records that point to 192.168.0.1 or 0.0.0.0,” Brundage wrote in a first-of-its-kind security advisory sent to nearly a dozen residential proxy providers in mid-December 2025. “This grants an attacker the ability to send carefully crafted requests to the current device or a device on the local network. This is actively being exploited, with attackers leveraging this functionality to drop malware.”

As with the digital photo frames mentioned above, many of these residential proxy services run solely on mobile devices that are running some game, VPN or other app with a hidden component that turns the user’s mobile phone into a residential proxy — often without any meaningful consent.

In a report published today, Synthient said key actors involved in Kimwolf were observed monetizing the botnet through app installs, selling residential proxy bandwidth, and selling its DDoS functionality.

“Synthient expects to observe a growing interest among threat actors in gaining unrestricted access to proxy networks to infect devices, obtain network access, or access sensitive information,” the report observed. “Kimwolf highlights the risks posed by unsecured proxy networks and their viability as an attack vector.”

ANDROID DEBUG BRIDGE

After purchasing a number of unofficial Android TV box models that were most heavily represented in the Kimwolf botnet, Brundage further discovered the proxy service vulnerability was only part of the reason for Kimwolf’s rapid rise: He also found virtually all of the devices he tested were shipped from the factory with a powerful feature called Android Debug Bridge (ADB) mode enabled by default.

ADB is a diagnostic tool intended for use solely during the manufacturing and testing processes, because it allows the devices to be remotely configured and even updated with new (and potentially malicious) firmware. However, shipping these devices with ADB turned on creates a security nightmare because in this state they constantly listen for and accept unauthenticated connection requests.

For example, opening a command prompt and typing “adb connect” along with a vulnerable device’s (local) IP address followed immediately by “:5555” will very quickly offer unrestricted “super user” administrative access.

Brundage said by early December, he’d identified a one-to-one overlap between new Kimwolf infections and proxy IP addresses offered for rent by China-based IPIDEA, currently the world’s largest residential proxy network by all accounts.

“Kimwolf has almost doubled in size this past week, just by exploiting IPIDEA’s proxy pool,” Brundage told KrebsOnSecurity in early December as he was preparing to notify IPIDEA and 10 other proxy providers about his research.

Brundage said Synthient first confirmed on December 1, 2025 that the Kimwolf botnet operators were tunneling back through IPIDEA’s proxy network and into the local networks of systems running IPIDEA’s proxy software. The attackers dropped the malware payload by directing infected systems to visit a specific Internet address and to call out the pass phrase “krebsfiveheadindustries” in order to unlock the malicious download.

On December 30, Synthient said it was tracking roughly 2 million IPIDEA addresses exploited by Kimwolf in the previous week. Brundage said he has witnessed Kimwolf rebuilding itself after one recent takedown effort targeting its control servers — from almost nothing to two million infected systems just by tunneling through proxy endpoints on IPIDEA for a couple of days.

Brundage said IPIDEA has a seemingly inexhaustible supply of new proxies, advertising access to more than 100 million residential proxy endpoints around the globe in the past week alone. Analyzing the exposed devices that were part of IPIDEA’s proxy pool, Synthient said it found more than two-thirds were Android devices that could be compromised with no authentication needed.

SECURITY NOTIFICATION AND RESPONSE

After charting a tight overlap in Kimwolf-infected IP addresses and those sold by IPIDEA, Brundage was eager to make his findings public: The vulnerability had clearly been exploited for several months, although it appeared that only a handful of cybercrime actors were aware of the capability. But he also knew that going public without giving vulnerable proxy providers an opportunity to understand and patch it would only lead to more mass abuse of these services by additional cybercriminal groups.

On December 17, Brundage sent a security notification to all 11 of the apparently affected proxy providers, hoping to give each at least a few weeks to acknowledge and address the core problems identified in his report before he went public. Many proxy providers who received the notification were resellers of IPIDEA that white-labeled the company’s service.

KrebsOnSecurity first sought comment from IPIDEA in October 2025, in reporting on a story about how the proxy network appeared to have benefitted from the rise of the Aisuru botnet, whose administrators appeared to shift from using the botnet primarily for DDoS attacks to simply installing IPIDEA’s proxy program, among others.

On December 25, KrebsOnSecurity received an email from an IPIDEA employee identified only as “Oliver,” who said allegations that IPIDEA had benefitted from Aisuru’s rise were baseless.

“After comprehensively verifying IP traceability records and supplier cooperation agreements, we found no association between any of our IP resources and the Aisuru botnet, nor have we received any notifications from authoritative institutions regarding our IPs being involved in malicious activities,” Oliver wrote. “In addition, for external cooperation, we implement a three-level review mechanism for suppliers, covering qualification verification, resource legality authentication and continuous dynamic monitoring, to ensure no compliance risks throughout the entire cooperation process.”

“IPIDEA firmly opposes all forms of unfair competition and malicious smearing in the industry, always participates in market competition with compliant operation and honest cooperation, and also calls on the entire industry to jointly abandon irregular and unethical behaviors and build a clean and fair market ecosystem,” Oliver continued.

Meanwhile, the same day that Oliver’s email arrived, Brundage shared a response he’d just received from IPIDEA’s security officer, who identified himself only by the first name Byron. The security officer said IPIDEA had made a number of important security changes to its residential proxy service to address the vulnerability identified in Brundage’s report.

“By design, the proxy service does not allow access to any internal or local address space,” Byron explained. “This issue was traced to a legacy module used solely for testing and debugging purposes, which did not fully inherit the internal network access restrictions. Under specific conditions, this module could be abused to reach internal resources. The affected paths have now been fully blocked and the module has been taken offline.”

Byron told Brundage IPIDEA also instituted multiple mitigations for blocking DNS resolution to internal (NAT) IP ranges, and that it was now blocking proxy endpoints from forwarding traffic on “high-risk” ports “to prevent abuse of the service for scanning, lateral movement, or access to internal services.”

Brundage said IPIDEA appears to have successfully patched the vulnerabilities he identified. He also noted he never observed the Kimwolf actors targeting proxy services other than IPIDEA, which has not responded to requests for comment.

Riley Kilmer is founder of Spur.us, a technology firm that helps companies identify and filter out proxy traffic. Kilmer said Spur has tested Brundage’s findings and confirmed that IPIDEA and all of its affiliate resellers indeed allowed full and unfiltered access to the local LAN.

Kilmer said one model of unsanctioned Android TV boxes that is especially popular — the Superbox, which we profiled in November’s Is Your Android TV Streaming Box Part of a Botnet? — leaves Android Debug Mode running on localhost:5555.

“And since Superbox turns the IP into an IPIDEA proxy, a bad actor just has to use the proxy to localhost on that port and install whatever bad SDKs [software development kits] they want,” Kilmer told KrebsOnSecurity.

ECHOES FROM THE PAST

Both Brundage and Kilmer say IPIDEA appears to be the second or third reincarnation of a residential proxy network formerly known as 911S5 Proxy, a service that operated between 2014 and 2022 and was wildly popular on cybercrime forums. 911S5 Proxy imploded a week after KrebsOnSecurity published a deep dive on the service’s sketchy origins and leadership in China.

In that 2022 profile, we cited work by researchers at the University of Sherbrooke in Canada who were studying the threat 911S5 could pose to internal corporate networks. The researchers noted that “the infection of a node enables the 911S5 user to access shared resources on the network such as local intranet portals or other services.”

“It also enables the end user to probe the LAN network of the infected node,” the researchers explained. “Using the internal router, it would be possible to poison the DNS cache of the LAN router of the infected node, enabling further attacks.”

911S5 initially responded to our reporting in 2022 by claiming it was conducting a top-down security review of the service. But the proxy service abruptly closed up shop just one week later, saying a malicious hacker had destroyed all of the company’s customer and payment records. In July 2024, The U.S. Department of the Treasury sanctioned the alleged creators of 911S5, and the U.S. Department of Justice arrested the Chinese national named in my 2022 profile of the proxy service.

Kilmer said IPIDEA also operates a sister service called 922 Proxy, which the company has pitched from Day One as a seamless alternative to 911S5 Proxy.

“You cannot tell me they don’t want the 911 customers by calling it that,” Kilmer said.

Among the recipients of Synthient’s notification was the proxy giant Oxylabs. Brundage shared an email he received from Oxylabs’ security team on December 31, which acknowledged Oxylabs had started rolling out security modifications to address the vulnerabilities described in Synthient’s report.

Reached for comment, Oxylabs confirmed they “have implemented changes that now eliminate the ability to bypass the blocklist and forward requests to private network addresses using a controlled domain.” But it said there is no evidence that Kimwolf or other other attackers exploited its network.

“In parallel, we reviewed the domains identified in the reported exploitation activity and did not observe traffic associated with them,” the Oxylabs statement continued. “Based on this review, there is no indication that our residential network was impacted by these activities.”

PRACTICAL IMPLICATIONS

Consider the following scenario, in which the mere act of allowing someone to use your Wi-Fi network could lead to a Kimwolf botnet infection. In this example, a friend or family member comes to stay with you for a few days, and you grant them access to your Wi-Fi without knowing that their mobile phone is infected with an app that turns the device into a residential proxy node. At that point, your home’s public IP address will show up for rent at the website of some residential proxy provider.

Miscreants like those behind Kimwolf then use residential proxy services online to access that proxy node on your IP, tunnel back through it and into your local area network (LAN), and automatically scan the internal network for devices with Android Debug Bridge mode turned on.

By the time your guest has packed up their things, said their goodbyes and disconnected from your Wi-Fi, you now have two devices on your local network — a digital photo frame and an unsanctioned Android TV box — that are infected with Kimwolf. You may have never intended for these devices to be exposed to the larger Internet, and yet there you are.

Here’s another possible nightmare scenario: Attackers use their access to proxy networks to modify your Internet router’s settings so that it relies on malicious DNS servers controlled by the attackers — allowing them to control where your Web browser goes when it requests a website. Think that’s far-fetched? Recall the DNSChanger malware from 2012 that infected more than a half-million routers with search-hijacking malware, and ultimately spawned an entire security industry working group focused on containing and eradicating it.

XLAB

Much of what is published so far on Kimwolf has come from the Chinese security firm XLab, which was the first to chronicle the rise of the Aisuru botnet in late 2024. In its latest blog post, XLab said it began tracking Kimwolf on October 24, when the botnet’s control servers were swamping Cloudflare’s DNS servers with lookups for the distinctive domain 14emeliaterracewestroxburyma02132[.]su.

This domain and others connected to early Kimwolf variants spent several weeks topping Cloudflare’s chart of the Internet’s most sought-after domains, edging out Google.com and Apple.com of their rightful spots in the top 5 most-requested domains. That’s because during that time Kimwolf was asking its millions of bots to check in frequently using Cloudflare’s DNS servers.

It is clear from reading the XLab report that KrebsOnSecurity (and security experts) probably erred in misattributing some of Kimwolf’s early activities to the Aisuru botnet, which appears to be operated by a different group entirely. IPDEA may have been truthful when it said it had no affiliation with the Aisuru botnet, but Brundage’s data left no doubt that its proxy service clearly was being massively abused by Aisuru’s Android variant, Kimwolf.

XLab said Kimwolf has infected at least 1.8 million devices, and has shown it is able to rebuild itself quickly from scratch.

“Analysis indicates that Kimwolf’s primary infection targets are TV boxes deployed in residential network environments,” XLab researchers wrote. “Since residential networks usually adopt dynamic IP allocation mechanisms, the public IPs of devices change over time, so the true scale of infected devices cannot be accurately measured solely by the quantity of IPs. In other words, the cumulative observation of 2.7 million IP addresses does not equate to 2.7 million infected devices.”

XLab said measuring Kimwolf’s size also is difficult because infected devices are distributed across multiple global time zones. “Affected by time zone differences and usage habits (e.g., turning off devices at night, not using TV boxes during holidays, etc.), these devices are not online simultaneously, further increasing the difficulty of comprehensive observation through a single time window,” the blog post observed.

XLab noted that the Kimwolf author shows an almost ‘obsessive’ fixation” on Yours Truly, apparently leaving “easter eggs” related to my name in multiple places through the botnet’s code and communications:

ANALYSIS AND ADVICE

One frustrating aspect of threats like Kimwolf is that in most cases it is not easy for the average user to determine if there are any devices on their internal network which may be vulnerable to threats like Kimwolf and/or already infected with residential proxy malware.

Let’s assume that through years of security training or some dark magic you can successfully identify that residential proxy activity on your internal network was linked to a specific mobile device inside your house: From there, you’d still need to isolate and remove the app or unwanted component that is turning the device into a residential proxy.

Also, the tooling and knowledge needed to achieve this kind of visibility just isn’t there from an average consumer standpoint. The work that it takes to configure your network so you can see and interpret logs of all traffic coming in and out is largely beyond the skillset of most Internet users (and, I’d wager, many security experts). But it’s a topic worth exploring in an upcoming story.

Happily, Synthient has erected a page on its website that will state whether a visitor’s public Internet address was seen among those of Kimwolf-infected systems. Brundage also has compiled a list of the unofficial Android TV boxes that are most highly represented in the Kimwolf botnet.

If you own a TV box that matches one of these model names and/or numbers, please just rip it out of your network. If you encounter one of these devices on the network of a family member or friend, send them a link to this story and explain that it’s not worth the potential hassle and harm created by keeping them plugged in.

Chad Seaman is a principal security researcher with Akamai Technologies. Seaman said he wants more consumers to be wary of these pseudo Android TV boxes to the point where they avoid them altogether.

“I want the consumer to be paranoid of these crappy devices and of these residential proxy schemes,” he said. “We need to highlight why they’re dangerous to everyone and to the individual. The whole security model where people think their LAN (Local Internal Network) is safe, that there aren’t any bad guys on the LAN so it can’t be that dangerous is just really outdated now.”

“The idea that an app can enable this type of abuse on my network and other networks, that should really give you pause,” about which devices to allow onto your local network, Seaman said. “And it’s not just Android devices here. Some of these proxy services have SDKs for Mac and Windows, and the iPhone. It could be running something that inadvertently cracks open your network and lets countless random people inside.”

In July 2025, Google filed a “John Doe” lawsuit (PDF) against 25 unidentified defendants collectively dubbed the “BadBox 2.0 Enterprise,” which Google described as a botnet of over ten million unsanctioned Android streaming devices engaged in advertising fraud. Google said the BADBOX 2.0 botnet, in addition to compromising multiple types of devices prior to purchase, also can infect devices by requiring the download of malicious apps from unofficial marketplaces.

Google’s lawsuit came on the heels of a June 2025 advisory from the Federal Bureau of Investigation (FBI), which warned that cyber criminals were gaining unauthorized access to home networks by either configuring the products with malware prior to the user’s purchase, or infecting the device as it downloads required applications that contain backdoors — usually during the set-up process.

The FBI said BADBOX 2.0 was discovered after the original BADBOX campaign was disrupted in 2024. The original BADBOX was identified in 2023, and primarily consisted of Android operating system devices that were compromised with backdoor malware prior to purchase.

Lindsay Kaye is vice president of threat intelligence at HUMAN Security, a company that worked closely on the BADBOX investigations. Kaye said the BADBOX botnets and the residential proxy networks that rode on top of compromised devices were detected because they enabled a ridiculous amount of advertising fraud, as well as ticket scalping, retail fraud, account takeovers and content scraping.

Kaye said consumers should stick to known brands when it comes to purchasing things that require a wired or wireless connection.

“If people are asking what they can do to avoid being victimized by proxies, it’s safest to stick with name brands,” Kaye said. “Anything promising something for free or low-cost, or giving you something for nothing just isn’t worth it. And be careful about what apps you allow on your phone.”

Many wireless routers these days make it relatively easy to deploy a “Guest” wireless network on-the-fly. Doing so allows your guests to browse the Internet just fine but it blocks their device from being able to talk to other devices on the local network — such as shared folders, printers and drives. If someone — a friend, family member, or contractor — requests access to your network, give them the guest Wi-Fi network credentials if you have that option.

There is a small but vocal pro-piracy camp that is almost condescendingly dismissive of the security threats posed by these unsanctioned Android TV boxes. These tech purists positively chafe at the idea of people wholesale discarding one of these TV boxes. A common refrain from this camp is that Internet-connected devices are not inherently bad or good, and that even factory-infected boxes can be flashed with new firmware or custom ROMs that contain no known dodgy software.

However, it’s important to point out that the majority of people buying these devices are not security or hardware experts; the devices are sought out because they dangle something of value for “free.” Most buyers have no idea of the bargain they’re making when plugging one of these dodgy TV boxes into their network.

It is somewhat remarkable that we haven’t yet seen the entertainment industry applying more visible pressure on the major e-commerce vendors to stop peddling this insecure and actively malicious hardware that is largely made and marketed for video piracy. These TV boxes are a public nuisance for bundling malicious software while having no apparent security or authentication built-in, and these two qualities make them an attractive nuisance for cybercriminals.

Stay tuned for Part II in this series, which will poke through clues left behind by the people who appear to have built Kimwolf and benefited from it the most.

Happy 16th Birthday, KrebsOnSecurity.com!

KrebsOnSecurity.com celebrates its 16th anniversary today! A huge “thank you” to all of our readers — newcomers, long-timers and drive-by critics alike. Your engagement this past year here has been tremendous and truly a salve on a handful of dark days. Happily, comeuppance was a strong theme running through our coverage in 2025, with a primary focus on entities that enabled complex and globally-dispersed cybercrime services.

In May 2024, we scrutinized the history and ownership of Stark Industries Solutions Ltd., a “bulletproof hosting” provider that came online just two weeks before Russia invaded Ukraine and served as a primary staging ground for repeated Kremlin cyberattacks and disinformation efforts. A year later, Stark and its two co-owners were sanctioned by the European Union, but our analysis showed those penalties have done little to stop the Stark proprietors from rebranding and transferring considerable network assets to other entities they control.

In December 2024, KrebsOnSecurity profiled Cryptomus, a financial firm registered in Canada that emerged as the payment processor of choice for dozens of Russian cryptocurrency exchanges and websites hawking cybercrime services aimed at Russian-speaking customers. In October 2025, Canadian financial regulators ruled that Cryptomus had grossly violated its anti-money laundering laws, and levied a record $176 million fine against the platform.

In September 2023, KrebsOnSecurity published findings from researchers who concluded that a series of six-figure cyberheists across dozens of victims resulted from thieves cracking master passwords stolen from the password manager service LastPass in 2022. In a court filing in March 2025, U.S. federal agents investigating a spectacular $150 million cryptocurrency heist said they had reached the same conclusion.

Phishing was a major theme of this year’s coverage, which peered inside the day-to-day operations of several voice phishing gangs that routinely carried out elaborate, convincing, and financially devastating cryptocurrency thefts. A Day in the Life of a Prolific Voice Phishing Crew examined how one cybercrime gang abused legitimate services at Apple and Google to force a variety of outbound communications to their users, including emails, automated phone calls and system-level messages sent to all signed-in devices.

Nearly a half-dozen stories in 2025 dissected the incessant SMS phishing or “smishing” coming from China-based phishing kit vendors, who make it easy for customers to convert phished payment card data into mobile wallets from Apple and Google. In an effort to wrest control over this phishing syndicate’s online resources, Google has since filed at least two John Doe lawsuits targeting these groups and dozens of unnamed defendants.

In January, we highlighted research into a dodgy and sprawling content delivery network called Funnull that specialized in helping China-based gambling and money laundering websites distribute their operations across multiple U.S.-based cloud providers. Five months later, the U.S. government sanctioned Funnull, identifying it as a top source of investment/romance scams known as “pig butchering.”

In May, Pakistan arrested 21 people alleged to be working for Heartsender, a phishing and malware dissemination service that KrebsOnSecurity first profiled back in 2015. The arrests came shortly after the FBI and the Dutch police seized dozens of servers and domains for the group. Many of those arrested were first publicly identified in a 2021 story here about how they’d inadvertently infected their computers with malware that gave away their real-life identities.

In April, the U.S. Department of Justice indicted the proprietors of a Pakistan-based e-commerce company for conspiring to distribute synthetic opioids in the United States. The following month, KrebsOnSecurity detailed how the proprietors of the sanctioned entity are perhaps better known for operating an elaborate and lengthy scheme to scam westerners seeking help with trademarks, book writing, mobile app development and logo designs.

Earlier this month, we examined an academic cheating empire turbocharged by Google Ads that earned tens of millions of dollars in revenue and has curious ties to a Kremlin-connected oligarch whose Russian university builds drones for Russia’s war against Ukraine.

As ever, KrebsOnSecurity endeavored to keep close tabs on the world’s biggest and most disruptive botnets, which pummeled the Internet this year with distributed denial-of-service (DDoS) assaults that were two to three times the size and impact of previous record DDoS attacks.

In June, KrebsOnSecurity.com was hit by the largest DDoS attack that Google had ever mitigated at the time (we are a grateful guest of Google’s excellent Project Shield offering). Experts blamed that attack on an Internet-of-Things botnet called Aisuru that had rapidly grown in size and firepower since its debut in late 2024. Another Aisuru attack on Cloudflare just days later practically doubled the size of the June attack against this website. Not long after that, Aisuru was blamed for a DDoS that again doubled the previous record.

In October, it appeared the cybercriminals in control of Aisuru had shifted the botnet’s focus from DDoS to a more sustainable and profitable use: Renting hundreds of thousands of infected Internet of Things (IoT) devices to proxy services that help cybercriminals anonymize their traffic.

However, it has recently become clear that at least some of the disruptive botnet and residential proxy activity attributed to Aisuru last year likely was the work of people responsible for building and testing a powerful botnet known as Kimwolf. Chinese security firm XLab, which was the first to chronicle Aisuru’s rise in 2024, recently profiled Kimwolf as easily the world’s biggest and most dangerous collection of compromised machines — with approximately 1.83 million devices under its thumb as of December 17.

XLab noted that the Kimwolf author “shows an almost ‘obsessive’ fixation on the well-known cybersecurity investigative journalist Brian Krebs, leaving easter eggs related to him in multiple places.”

I am happy to report that the first KrebsOnSecurity stories of 2026 will go deep into the origins of Kimwolf, and examine the botnet’s unique and highly invasive means of spreading digital disease far and wide. The first in that series will include a somewhat sobering and global security notification concerning the devices and residential proxy services that are inadvertently helping to power Kimwolf’s rapid growth.

Thank you once again for your continued readership, encouragement and support. If you like the content we publish at KrebsOnSecurity.com, please consider making an exception for our domain in your ad blocker. The ads we run are limited to a handful of static images that are all served in-house and vetted by me (there is no third-party content on this site, period). Doing so would help further support the work you see here almost every week.

And if you haven’t done so yet, sign up for our email newsletter! (62,000 other subscribers can’t be wrong, right?). The newsletter is just a plain text email that goes out the moment a new story is published. We send between one and two emails a week, we never share our email list, and we don’t run surveys or promotions.

Thanks again, and Happy New Year everyone! Be safe out there.

Cloudflare Scrubs Aisuru Botnet from Top Domains List

For the past week, domains associated with the massive Aisuru botnet have repeatedly usurped Amazon, Apple, Google and Microsoft in Cloudflare’s public ranking of the most frequently requested websites. Cloudflare responded by redacting Aisuru domain names from their top websites list. The chief executive at Cloudflare says Aisuru’s overlords are using the botnet to boost their malicious domain rankings, while simultaneously attacking the company’s domain name system (DNS) service.

Aisuru is a rapidly growing botnet comprising hundreds of thousands of hacked Internet of Things (IoT) devices, such as poorly secured Internet routers and security cameras. The botnet has increased in size and firepower significantly since its debut in 2024, demonstrating the ability to launch record distributed denial-of-service (DDoS) attacks nearing 30 terabits of data per second.

Until recently, Aisuru’s malicious code instructed all infected systems to use DNS servers from Google — specifically, the servers at 8.8.8.8. But in early October, Aisuru switched to invoking Cloudflare’s main DNS server — 1.1.1.1 — and over the past week domains used by Aisuru to control infected systems started populating Cloudflare’s top domain rankings.

As screenshots of Aisuru domains claiming two of the Top 10 positions ping-ponged across social media, many feared this was yet another sign that an already untamable botnet was running completely amok. One Aisuru botnet domain that sat prominently for days at #1 on the list was someone’s street address in Massachusetts followed by “.com”. Other Aisuru domains mimicked those belonging to major cloud providers.

Cloudflare tried to address these security, brand confusion and privacy concerns by partially redacting the malicious domains, and adding a warning at the top of its rankings:

“Note that the top 100 domains and trending domains lists include domains with organic activity as well as domains with emerging malicious behavior.”

Cloudflare CEO Matthew Prince told KrebsOnSecurity the company’s domain ranking system is fairly simplistic, and that it merely measures the volume of DNS queries to 1.1.1.1.

“The attacker is just generating a ton of requests, maybe to influence the ranking but also to attack our DNS service,” Prince said, adding that Cloudflare has heard reports of other large public DNS services seeing similar uptick in attacks. “We’re fixing the ranking to make it smarter. And, in the meantime, redacting any sites we classify as malware.”

Renee Burton, vice president of threat intel at the DNS security firm Infoblox, said many people erroneously assumed that the skewed Cloudflare domain rankings meant there were more bot-infected devices than there were regular devices querying sites like Google and Apple and Microsoft.

“Cloudflare’s documentation is clear — they know that when it comes to ranking domains you have to make choices on how to normalize things,” Burton wrote on LinkedIn. “There are many aspects that are simply out of your control. Why is it hard? Because reasons. TTL values, caching, prefetching, architecture, load balancing. Things that have shared control between the domain owner and everything in between.”

Alex Greenland is CEO of the anti-phishing and security firm Epi. Greenland said he understands the technical reason why Aisuru botnet domains are showing up in Cloudflare’s rankings (those rankings are based on DNS query volume, not actual web visits). But he said they’re still not meant to be there.

“It’s a failure on Cloudflare’s part, and reveals a compromise of the trust and integrity of their rankings,” he said.

Greenland said Cloudflare planned for its Domain Rankings to list the most popular domains as used by human users, and it was never meant to be a raw calculation of query frequency or traffic volume going through their 1.1.1.1 DNS resolver.

“They spelled out how their popularity algorithm is designed to reflect real human use and exclude automated traffic (they said they’re good at this),” Greenland wrote on LinkedIn. “So something has evidently gone wrong internally. We should have two rankings: one representing trust and real human use, and another derived from raw DNS volume.”

Why might it be a good idea to wholly separate malicious domains from the list? Greenland notes that Cloudflare Domain Rankings see widespread use for trust and safety determination, by browsers, DNS resolvers, safe browsing APIs and things like TRANCO.

“TRANCO is a respected open source list of the top million domains, and Cloudflare Radar is one of their five data providers,” he continued. “So there can be serious knock-on effects when a malicious domain features in Cloudflare’s top 10/100/1000/million. To many people and systems, the top 10 and 100 are naively considered safe and trusted, even though algorithmically-defined top-N lists will always be somewhat crude.”

Over this past week, Cloudflare started redacting portions of the malicious Aisuru domains from its Top Domains list, leaving only their domain suffix visible. Sometime in the past 24 hours, Cloudflare appears to have begun hiding the malicious Aisuru domains entirely from the web version of that list. However, downloading a spreadsheet of the current Top 200 domains from Cloudflare Radar shows an Aisuru domain still at the very top.

According to Cloudflare’s website, the majority of DNS queries to the top Aisuru domains — nearly 52 percent — originated from the United States. This tracks with my reporting from early October, which found Aisuru was drawing most of its firepower from IoT devices hosted on U.S. Internet providers like AT&T, Comcast and Verizon.

Experts tracking Aisuru say the botnet relies on well more than a hundred control servers, and that for the moment at least most of those domains are registered in the .su top-level domain (TLD). Dot-su is the TLD assigned to the former Soviet Union (.su’s Wikipedia page says the TLD was created just 15 months before the fall of the Berlin wall).

A Cloudflare blog post from October 27 found that .su had the highest “DNS magnitude” of any TLD, referring to a metric estimating the popularity of a TLD based on the number of unique networks querying Cloudflare’s 1.1.1.1 resolver. The report concluded that the top .su hostnames were associated with a popular online world-building game, and that more than half of the queries for that TLD came from the United States, Brazil and Germany [it’s worth noting that servers for the world-building game Minecraft were some of Aisuru’s most frequent targets].

A simple and crude way to detect Aisuru bot activity on a network may be to set an alert on any systems attempting to contact domains ending in .su. This TLD is frequently abused for cybercrime and by cybercrime forums and services, and blocking access to it entirely is unlikely to raise any legitimate complaints.

Aisuru Botnet Shifts from DDoS to Residential Proxies

Aisuru, the botnet responsible for a series of record-smashing distributed denial-of-service (DDoS) attacks this year, recently was overhauled to support a more low-key, lucrative and sustainable business: Renting hundreds of thousands of infected Internet of Things (IoT) devices to proxy services that help cybercriminals anonymize their traffic. Experts say a glut of proxies from Aisuru and other sources is fueling large-scale data harvesting efforts tied to various artificial intelligence (AI) projects, helping content scrapers evade detection by routing their traffic through residential connections that appear to be regular Internet users.

First identified in August 2024, Aisuru has spread to at least 700,000 IoT systems, such as poorly secured Internet routers and security cameras. Aisuru’s overlords have used their massive botnet to clobber targets with headline-grabbing DDoS attacks, flooding targeted hosts with blasts of junk requests from all infected systems simultaneously.

In June, Aisuru hit KrebsOnSecurity.com with a DDoS clocking at 6.3 terabits per second — the biggest attack that Google had ever mitigated at the time. In the weeks and months that followed, Aisuru’s operators demonstrated DDoS capabilities of nearly 30 terabits of data per second — well beyond the attack mitigation capabilities of most Internet destinations.

These digital sieges have been particularly disruptive this year for U.S.-based Internet service providers (ISPs), in part because Aisuru recently succeeded in taking over a large number of IoT devices in the United States. And when Aisuru launches attacks, the volume of outgoing traffic from infected systems on these ISPs is often so high that it can disrupt or degrade Internet service for adjacent (non-botted) customers of the ISPs.

“Multiple broadband access network operators have experienced significant operational impact due to outbound DDoS attacks in excess of 1.5Tb/sec launched from Aisuru botnet nodes residing on end-customer premises,” wrote Roland Dobbins, principal engineer at Netscout, in a recent executive summary on Aisuru. “Outbound/crossbound attack traffic exceeding 1Tb/sec from compromised customer premise equipment (CPE) devices has caused significant disruption to wireline and wireless broadband access networks. High-throughput attacks have caused chassis-based router line card failures.”

The incessant attacks from Aisuru have caught the attention of federal authorities in the United States and Europe (many of Aisuru’s victims are customers of ISPs and hosting providers based in Europe). Quite recently, some of the world’s largest ISPs have started informally sharing block lists identifying the rapidly shifting locations of the servers that the attackers use to control the activities of the botnet.

Experts say the Aisuru botmasters recently updated their malware so that compromised devices can more easily be rented to so-called “residential proxy” providers. These proxy services allow paying customers to route their Internet communications through someone else’s device, providing anonymity and the ability to appear as a regular Internet user in almost any major city worldwide.

From a website’s perspective, the IP traffic of a residential proxy network user appears to originate from the rented residential IP address, not from the proxy service customer. Proxy services can be used in a legitimate manner for several business purposes — such as price comparisons or sales intelligence. But they are massively abused for hiding cybercrime activity (think advertising fraud, credential stuffing) because they can make it difficult to trace malicious traffic to its original source.

And as we’ll see in a moment, this entire shadowy industry appears to be shifting its focus toward enabling aggressive content scraping activity that continuously feeds raw data into large language models (LLMs) built to support various AI projects.

‘INSANE’ GROWTH

Riley Kilmer is co-founder of spur.us, a service that tracks proxy networks. Kilmer said all of the top proxy services have grown substantially over the past six months.

“I just checked, and in the last 90 days we’ve seen 250 million unique residential proxy IPs,” Kilmer said. “That is insane. That is so high of a number, it’s unheard of. These proxies are absolutely everywhere now.”

Today, Spur says it is tracking an unprecedented spike in available proxies across all providers, including;

LUMINATI_PROXY    11,856,421
NETNUT_PROXY    10,982,458
ABCPROXY_PROXY    9,294,419
OXYLABS_PROXY     6,754,790
IPIDEA_PROXY     3,209,313
EARNFM_PROXY    2,659,913
NODEMAVEN_PROXY    2,627,851
INFATICA_PROXY    2,335,194
IPROYAL_PROXY    2,032,027
YILU_PROXY    1,549,155

Reached for comment about the apparent rapid growth in their proxy network, Oxylabs (#4 on Spur’s list) said while their proxy pool did grow recently, it did so at nowhere near the rate cited by Spur.

“We don’t systematically track other providers’ figures, and we’re not aware of any instances of 10× or 100× growth, especially when it comes to a few bigger companies that are legitimate businesses,” the company said in a written statement.

Bright Data was formerly known as Luminati Networks, the name that is currently at the top of Spur’s list of the biggest residential proxy networks. Bright Data likewise told KrebsOnSecurity that Spur’s current estimates of its proxy network are dramatically overstated and inaccurate.

“We did not actively initiate nor do we see any 10x or 100x expansion of our network, which leads me to believe that someone might be presenting these IPs as Bright Data’s in some way,” said Rony Shalit, Bright Data’s chief compliance and ethics officer. “In many cases in the past, due to us being the leading data collection proxy provider, IPs were falsely tagged as being part of our network, or while being used by other proxy providers for malicious activity.”

“Our network is only sourced from verified IP providers and a robust opt-in only residential peers, which we work hard and in complete transparency to obtain,” Shalit continued. “Every DC, ISP or SDK partner is reviewed and approved, and every residential peer must actively opt in to be part of our network.”

HK NETWORK

Even Spur acknowledges that Luminati and Oxylabs are unlike most other proxy services on their top proxy providers list, in that these providers actually adhere to “know-your-customer” policies, such as requiring video calls with all customers, and strictly blocking customers from reselling access.

Benjamin Brundage is founder of Synthient, a startup that helps companies detect proxy networks. Brundage said if there is increasing confusion around which proxy networks are the most worrisome, it’s because nearly all of these lesser-known proxy services have evolved into highly incestuous bandwidth resellers. What’s more, he said, some proxy providers do not appreciate being tracked and have been known to take aggressive steps to confuse systems that scan the Internet for residential proxy nodes.

Brundage said most proxy services today have created their own software development kit or SDK that other app developers can bundle with their code to earn revenue. These SDKs quietly modify the user’s device so that some portion of their bandwidth can be used to forward traffic from proxy service customers.

“Proxy providers have pools of constantly churning IP addresses,” he said. “These IP addresses are sourced through various means, such as bandwidth-sharing apps, botnets, Android SDKs, and more. These providers will often either directly approach resellers or offer a reseller program that allows users to resell bandwidth through their platform.”

Many SDK providers say they require full consent before allowing their software to be installed on end-user devices. Still, those opt-in agreements and consent checkboxes may be little more than a formality for cybercriminals like the Aisuru botmasters, who can earn a commission each time one of their infected devices is forced to install some SDK that enables one or more of these proxy services.

Depending on its structure, a single provider may operate hundreds of different proxy pools at a time — all maintained through other means, Brundage said.

“Often, you’ll see resellers maintaining their own proxy pool in addition to an upstream provider,” he said. “It allows them to market a proxy pool to high-value clients and offer an unlimited bandwidth plan for cheap reduce their own costs.”

Some proxy providers appear to be directly in league with botmasters. Brundage identified one proxy seller that was aggressively advertising cheap and plentiful bandwidth to content scraping companies. After scanning that provider’s pool of available proxies, Brundage said he found a one-to-one match with IP addresses he’d previously mapped to the Aisuru botnet.

Brundage says that by almost any measurement, the world’s largest residential proxy service is IPidea, a China-based proxy network. IPidea is #5 on Spur’s Top 10, and Brundage said its brands include ABCProxy (#3), Roxlabs, LunaProxy, PIA S5 Proxy, PyProxy, 922Proxy, 360Proxy, IP2World, and Cherry Proxy. Spur’s Kilmer said they also track Yilu Proxy (#10) as IPidea.

Brundage said all of these providers operate under a corporate umbrella known on the cybercrime forums as “HK Network.”

“The way it works is there’s this whole reseller ecosystem, where IPidea will be incredibly aggressive and approach all these proxy providers with the offer, ‘Hey, if you guys buy bandwidth from us, we’ll give you these amazing reseller prices,'” Brundage explained. “But they’re also very aggressive in recruiting resellers for their apps.”

Those apps include a range of low-cost and “free” virtual private networking (VPN) services that indeed allow users to enjoy a free VPN, but which also turn the user’s device into a traffic relay that can be rented to cybercriminals, or else parceled out to countless other proxy networks.

“They have all this bandwidth to offload,” Brundage said of IPidea and its sister networks. “And they can do it through their own platforms, or they go get resellers to do it for them by advertising on sketchy hacker forums to reach more people.”

One of IPidea’s core brands is 922S5Proxy, which is a not-so-subtle nod to the 911S5Proxy service that was hugely popular between 2015 and 2022. In July 2022, KrebsOnSecurity published a deep dive into 911S5Proxy’s origins and apparent owners in China. Less than a week later, 911S5Proxy announced it was closing down after the company’s servers were massively hacked.

That 2022 story named Yunhe Wang from Beijing as the apparent owner and/or manager of the 911S5 proxy service. In May 2024, the U.S. Department of Justice arrested Mr Wang, alleging that his network was used to steal billions of dollars from financial institutions, credit card issuers, and federal lending programs. At the same time, the U.S. Treasury Department announced sanctions against Wang and two other Chinese nationals for operating 911S5Proxy.

DATA SCRAPING FOR AI

In recent months, multiple experts who track botnet and proxy activity have shared that a great deal of content scraping which ultimately benefits AI companies is now leveraging these proxy networks to further obfuscate their aggressive data-slurping activity. That’s because by routing it through residential IP addresses, content scraping firms can make their traffic far trickier to filter out.

“It’s really difficult to block, because there’s a risk of blocking real people,” Spur’s Kilmer said of the LLM scraping activity that is fed through individual residential IP addresses, which are often shared by multiple customers at once.

Kilmer says the AI industry has brought a veneer of legitimacy to residential proxy business, which has heretofore mostly been associated with sketchy affiliate money making programs, automated abuse, and unwanted Internet traffic.

“Web crawling and scraping has always been a thing, but AI made it like a commodity, data that had to be collected,” Kilmer said. “Everybody wanted to monetize their own data pots, and how they monetize that is different across the board.”

Kilmer said many LLM-related scrapers rely on residential proxies in cases where the content provider has restricted access to their platform in some way, such as forcing interaction through an app, or keeping all content behind a login page with multi-factor authentication.

“Where the cost of data is out of reach — there is some exclusivity or reason they can’t access the data — they’ll turn to residential proxies so they look like a real person accessing that data,” Kilmer said of the content scraping efforts.

Aggressive AI crawlers increasingly are overloading community-maintained infrastructure, causing what amounts to persistent DDoS attacks on vital public resources. A report earlier this year from LibreNews found some open-source projects now see as much as 97 percent of their traffic originating from AI company bots, dramatically increasing bandwidth costs, service instability, and burdening already stretched-thin maintainers.

Cloudflare is now experimenting with tools that will allow content creators to charge a fee to AI crawlers to scrape their websites. The company’s “pay-per-crawl” feature is currently in a private beta, and it lets publishers set their own prices that bots must pay before scraping content.

On October 22, the social media and news network Reddit sued Oxylabs (PDF) and several other proxy providers, alleging that their systems enabled the mass-scraping of Reddit user content even though Reddit had taken steps to block such activity.

“Recognizing that Reddit denies scrapers like them access to its site, Defendants scrape the data from Google’s search results instead,” the lawsuit alleges. “They do so by masking their identities, hiding their locations, and disguising their web scrapers as regular people (among other techniques) to circumvent or bypass the security restrictions meant to stop them.”

Denas Grybauskas, chief governance and strategy officer at Oxylabs, said the company was shocked and disappointed by the lawsuit.

“Reddit has made no attempt to speak with us directly or communicate any potential concerns,” Grybauskas said in a written statement. “Oxylabs has always been and will continue to be a pioneer and an industry leader in public data collection, and it will not hesitate to defend itself against these allegations. Oxylabs’ position is that no company should claim ownership of public data that does not belong to them. It is possible that it is just an attempt to sell the same public data at an inflated price.”

As big and powerful as Aisuru may be, it is hardly the only botnet that is contributing to the overall broad availability of residential proxies. For example, on June 5 the FBI’s Internet Crime Complaint Center warned that an IoT malware threat dubbed BADBOX 2.0 had compromised millions of smart-TV boxes, digital projectors, vehicle infotainment units, picture frames, and other IoT devices.

In July, Google filed a lawsuit in New York federal court against the Badbox botnet’s alleged perpetrators. Google said the Badbox 2.0 botnet “compromised more than 10 million uncertified devices running Android’s open-source software, which lacks Google’s security protections. Cybercriminals infected these devices with pre-installed malware and exploited them to conduct large-scale ad fraud and other digital crimes.”

A FAMILIAR DOMAIN NAME

Brundage said the Aisuru botmasters have their own SDK, and for some reason part of its code tells many newly-infected systems to query the domain name fuckbriankrebs[.]com. This may be little more than an elaborate “screw you” to this site’s author: One of the botnet’s alleged partners goes by the handle “Forky,” and was identified in June by KrebsOnSecurity as a young man from Sao Paulo, Brazil.

Brundage noted that only systems infected with Aisuru’s Android SDK will be forced to resolve the domain. Initially, there was some discussion about whether the domain might have some utility as a “kill switch” capable of disrupting the botnet’s operations, although Brundage and others interviewed for this story say that is unlikely.

For one thing, they said, if the domain was somehow critical to the operation of the botnet, why was it still unregistered and actively for-sale? Why indeed, we asked. Happily, the domain name was deftly snatched up last week by Philippe Caturegli, “chief hacking officer” for the security intelligence company Seralys.

Caturegli enabled a passive DNS server on that domain and within a few hours received more than 700,000 requests for unique subdomains on fuckbriankrebs[.]com.

But even with that visibility into Aisuru, it is difficult to use this domain check-in feature to measure its true size, Brundage said. After all, he said, the systems that are phoning home to the domain are only a small portion of the overall botnet.

“The bots are hardcoded to just spam lookups on the subdomains,” he said. “So anytime an infection occurs or it runs in the background, it will do one of those DNS queries.”

The domain fuckbriankrebs[.]com has a storied history. On its initial launch in 2009, it was used to spread malicious software by the Cutwail spam botnet. In 2011, the domain was involved in a notable DDoS against this website from a botnet powered by Russkill (a.k.a. “Dirt Jumper”).

Domaintools.com finds that in 2015, fuckbriankrebs[.]com was registered to an email address attributed to David “Abdilo” Crees, a 27-year-old Australian man sentenced in May 2025 to time served for cybercrime convictions related to the Lizard Squad hacking group.

Update, Nov. 1, 2025, 10:25 a.m. ET: An earlier version of this story erroneously cited Spur’s proxy numbers from earlier this year; Spur said those numbers conflated residential proxies — which are rotating and attached to real end-user devices — with “ISP proxies” located at AT&T. ISP proxies, Spur said, involve tricking an ISP into routing a large number of IP addresses that are resold as far more static datacenter proxies.

DDoS Botnet Aisuru Blankets US ISPs in Record DDoS

The world’s largest and most disruptive botnet is now drawing a majority of its firepower from compromised Internet-of-Things (IoT) devices hosted on U.S. Internet providers like AT&T, Comcast and Verizon, new evidence suggests. Experts say the heavy concentration of infected devices at U.S. providers is complicating efforts to limit collateral damage from the botnet’s attacks, which shattered previous records this week with a brief traffic flood that clocked in at nearly 30 trillion bits of data per second.

Since its debut more than a year ago, the Aisuru botnet has steadily outcompeted virtually all other IoT-based botnets in the wild, with recent attacks siphoning Internet bandwidth from an estimated 300,000 compromised hosts worldwide.

The hacked systems that get subsumed into the botnet are mostly consumer-grade routers, security cameras, digital video recorders and other devices operating with insecure and outdated firmware, and/or factory-default settings. Aisuru’s owners are continuously scanning the Internet for these vulnerable devices and enslaving them for use in distributed denial-of-service (DDoS) attacks that can overwhelm targeted servers with crippling amounts of junk traffic.

As Aisuru’s size has mushroomed, so has its punch. In May 2025, KrebsOnSecurity was hit with a near-record 6.35 terabits per second (Tbps) attack from Aisuru, which was then the largest assault that Google’s DDoS protection service Project Shield had ever mitigated. Days later, Aisuru shattered that record with a data blast in excess of 11 Tbps.

By late September, Aisuru was publicly flexing DDoS capabilities topping 22 Tbps. Then on October 6, its operators heaved a whopping 29.6 terabits of junk data packets each second at a targeted host. Hardly anyone noticed because it appears to have been a brief test or demonstration of Aisuru’s capabilities: The traffic flood lasted less only a few seconds and was pointed at an Internet server that was specifically designed to measure large-scale DDoS attacks.

Aisuru’s overlords aren’t just showing off. Their botnet is being blamed for a series of increasingly massive and disruptive attacks. Although recent assaults from Aisuru have targeted mostly ISPs that serve online gaming communities like Minecraft, those digital sieges often result in widespread collateral Internet disruption.

For the past several weeks, ISPs hosting some of the Internet’s top gaming destinations have been hit with a relentless volley of gargantuan attacks that experts say are well beyond the DDoS mitigation capabilities of most organizations connected to the Internet today.

Steven Ferguson is principal security engineer at Global Secure Layer (GSL), an ISP in Brisbane, Australia. GSL hosts TCPShield, which offers free or low-cost DDoS protection to more than 50,000 Minecraft servers worldwide. Ferguson told KrebsOnSecurity that on October 8, TCPShield was walloped with a blitz from Aisuru that flooded its network with more than 15 terabits of junk data per second.

Ferguson said that after the attack subsided, TCPShield was told by its upstream provider OVH that they were no longer welcome as a customer.

“This was causing serious congestion on their Miami external ports for several weeks, shown publicly via their weather map,” he said, explaining that TCPShield is now solely protected by GSL.

Traces from the recent spate of crippling Aisuru attacks on gaming servers can be still seen at the website blockgametracker.gg, which indexes the uptime and downtime of the top Minecraft hosts. In the following example from a series of data deluges on the evening of September 28, we can see an Aisuru botnet campaign briefly knocked TCPShield offline.

Paging through the same uptime graphs for other network operators listed shows almost all of them suffered brief but repeated outages around the same time. Here is the same uptime tracking for Minecraft servers on the network provider Cosmic (AS30456), and it shows multiple large dips that correspond to game server outages caused by Aisuru.

BOTNETS R US

Ferguson said he’s been tracking Aisuru for about three months, and recently he noticed the botnet’s composition shifted heavily toward infected systems at ISPs in the United States. Ferguson shared logs from an attack on October 8 that indexed traffic by the total volume sent through each network provider, and the logs showed that 11 of the top 20 traffic sources were U.S. based ISPs.

AT&T customers were by far the biggest U.S. contributors to that attack, followed by botted systems on Charter Communications, Comcast, T-Mobile and Verizon, Ferguson found. He said the volume of data packets per second coming from infected IoT hosts on these ISPs is often so high that it has started to affect the quality of service that ISPs are able to provide to adjacent (non-botted) customers.

“The impact extends beyond victim networks,” Ferguson said. “For instance we have seen 500 gigabits of traffic via Comcast’s network alone. This amount of egress leaving their network, especially being so US-East concentrated, will result in congestion towards other services or content trying to be reached while an attack is ongoing.”

Roland Dobbins is principal engineer at Netscout. Dobbins said Ferguson is spot on, noting that while most ISPs have effective mitigations in place to handle large incoming DDoS attacks, many are far less prepared to manage the inevitable service degradation caused by large numbers of their customers suddenly using some or all available bandwidth to attack others.

“The outbound and cross-bound DDoS attacks can be just as disruptive as the inbound stuff,” Dobbin said. “We’re now in a situation where ISPs are routinely seeing terabit-per-second plus outbound attacks from their networks that can cause operational problems.”

“The crying need for effective and universal outbound DDoS attack suppression is something that is really being highlighted by these recent attacks,” Dobbins continued. “A lot of network operators are learning that lesson now, and there’s going to be a period ahead where there’s some scrambling and potential disruption going on.”

KrebsOnSecurity sought comment from the ISPs named in Ferguson’s report. Charter Communications pointed to a recent blog post on protecting its network, stating that Charter actively monitors for both inbound and outbound attacks, and that it takes proactive action wherever possible.

“In addition to our own extensive network security, we also aim to reduce the risk of customer connected devices contributing to attacks through our Advanced WiFi solution that includes Security Shield, and we make Security Suite available to our Internet customers,” Charter wrote in an emailed response to questions. “With the ever-growing number of devices connecting to networks, we encourage customers to purchase trusted devices with secure development and manufacturing practices, use anti-virus and security tools on their connected devices, and regularly download security patches.”

A spokesperson for Comcast responded, “Currently our network is not experiencing impacts and we are able to handle the traffic.”

9 YEARS OF MIRAI

Aisuru is built on the bones of malicious code that was leaked in 2016 by the original creators of the Mirai IoT botnet. Like Aisuru, Mirai quickly outcompeted all other DDoS botnets in its heyday, and obliterated previous DDoS attack records with a 620 gigabit-per-second siege that sidelined this website for nearly four days in 2016.

The Mirai botmasters likewise used their crime machine to attack mostly Minecraft servers, but with the goal of forcing Minecraft server owners to purchase a DDoS protection service that they controlled. In addition, they rented out slices of the Mirai botnet to paying customers, some of whom used it to mask the sources of other types of cybercrime, such as click fraud.

Dobbins said Aisuru’s owners also appear to be renting out their botnet as a distributed proxy network that cybercriminal customers anywhere in the world can use to anonymize their malicious traffic and make it appear to be coming from regular residential users in the U.S.

“The people who operate this botnet are also selling (it as) residential proxies,” he said. “And that’s being used to reflect application layer attacks through the proxies on the bots as well.”

The Aisuru botnet harkens back to its predecessor Mirai in another intriguing way. One of its owners is using the Telegram handle “9gigsofram,” which corresponds to the nickname used by the co-owner of a Minecraft server protection service called Proxypipe that was heavily targeted in 2016 by the original Mirai botmasters.

Robert Coelho co-ran Proxypipe back then along with his business partner Erik “9gigsofram” Buckingham, and has spent the past nine years fine-tuning various DDoS mitigation companies that cater to Minecraft server operators and other gaming enthusiasts. Coelho said he has no idea why one of Aisuru’s botmasters chose Buckingham’s nickname, but added that it might say something about how long this person has been involved in the DDoS-for-hire industry.

“The Aisuru attacks on the gaming networks these past seven day have been absolutely huge, and you can see tons of providers going down multiple times a day,” Coelho said.

Coelho said the 15 Tbps attack this week against TCPShield was likely only a portion of the total attack volume hurled by Aisuru at the time, because much of it would have been shoved through networks that simply couldn’t process that volume of traffic all at once. Such outsized attacks, he said, are becoming increasingly difficult and expensive to mitigate.

“It’s definitely at the point now where you need to be spending at least a million dollars a month just to have the network capacity to be able to deal with these attacks,” he said.

RAPID SPREAD

Aisuru has long been rumored to use multiple zero-day vulnerabilities in IoT devices to aid its rapid growth over the past year. XLab, the Chinese security company that was the first to profile Aisuru’s rise in 2024, warned last month that one of the Aisuru botmasters had compromised the firmware distribution website for Totolink, a maker of low-cost routers and other networking gear.

“Multiple sources indicate the group allegedly compromised a router firmware update server in April and distributed malicious scripts to expand the botnet,” XLab wrote on September 15. “The node count is currently reported to be around 300,000.”

Aisuru’s operators received an unexpected boost to their crime machine in August when the U.S. Department Justice charged the alleged proprietor of Rapper Bot, a DDoS-for-hire botnet that competed directly with Aisuru for control over the global pool of vulnerable IoT systems.

Once Rapper Bot was dismantled, Aisuru’s curators moved quickly to commandeer vulnerable IoT devices that were suddenly set adrift by the government’s takedown, Dobbins said.

“Folks were arrested and Rapper Bot control servers were seized and that’s great, but unfortunately the botnet’s attack assets were then pieced out by the remaining botnets,” he said. “The problem is, even if those infected IoT devices are rebooted and cleaned up, they will still get re-compromised by something else generally within minutes of being plugged back in.”

BOTMASTERS AT LARGE

XLab’s September blog post cited multiple unnamed sources saying Aisuru is operated by three cybercriminals: “Snow,” who’s responsible for botnet development; “Tom,” tasked with finding new vulnerabilities; and “Forky,” responsible for botnet sales.

KrebsOnSecurity interviewed Forky in our May 2025 story about the record 6.3 Tbps attack from Aisuru. That story identified Forky as a 21-year-old man from Sao Paulo, Brazil who has been extremely active in the DDoS-for-hire scene since at least 2022. The FBI has seized Forky’s DDoS-for-hire domains several times over the years.

Like the original Mirai botmasters, Forky also operates a DDoS mitigation service called Botshield. Forky declined to discuss the makeup of his ISP’s clientele, or to clarify whether Botshield was more of a hosting provider or a DDoS mitigation firm. However, Forky has posted on Telegram about Botshield successfully mitigating large DDoS attacks launched against other DDoS-for-hire services.

In our previous interview, Forky acknowledged being involved in the development and marketing of Aisuru, but denied participating in attacks launched by the botnet.

Reached for comment earlier this month, Forky continued to maintain his innocence, claiming that he also is still trying to figure out who the current Aisuru botnet operators are in real life (Forky said the same thing in our May interview).

But after a week of promising juicy details, Forky came up empty-handed once again. Suspecting that Forky was merely being coy, I asked him how someone so connected to the DDoS-for-hire world could still be mystified on this point, and suggested that his inability or unwillingness to blame anyone else for Aisuru would not exactly help his case.

At this, Forky verbally bristled at being pressed for more details, and abruptly terminated our interview.

“I’m not here to be threatened with ignorance because you are stressed,” Forky replied. “They’re blaming me for those new attacks. Pretty much the whole world (is) due to your blog.”

KrebsOnSecurity Hit With Near-Record 6.3 Tbps DDoS

KrebsOnSecurity last week was hit by a near record distributed denial-of-service (DDoS) attack that clocked in at more than 6.3 terabits of data per second (a terabit is one trillion bits of data). The brief attack appears to have been a test run for a massive new Internet of Things (IoT) botnet capable of launching crippling digital assaults that few web destinations can withstand. Read on for more about the botnet, the attack, and the apparent creator of this global menace.

For reference, the 6.3 Tbps attack last week was ten times the size of the assault launched against this site in 2016 by the Mirai IoT botnet, which held KrebsOnSecurity offline for nearly four days. The 2016 assault was so large that Akamai – which was providing pro-bono DDoS protection for KrebsOnSecurity at the time — asked me to leave their service because the attack was causing problems for their paying customers.

Since the Mirai attack, KrebsOnSecurity.com has been behind the protection of Project Shield, a free DDoS defense service that Google provides to websites offering news, human rights, and election-related content. Google Security Engineer Damian Menscher told KrebsOnSecurity the May 12 attack was the largest Google has ever handled. In terms of sheer size, it is second only to a very similar attack that Cloudflare mitigated and wrote about in April.

After comparing notes with Cloudflare, Menscher said the botnet that launched both attacks bears the fingerprints of Aisuru, a digital siege machine that first surfaced less than a year ago. Menscher said the attack on KrebsOnSecurity lasted less than a minute, hurling large UDP data packets at random ports at a rate of approximately 585 million data packets per second.

“It was the type of attack normally designed to overwhelm network links,” Menscher said, referring to the throughput connections between and among various Internet service providers (ISPs). “For most companies, this size of attack would kill them.”

The Aisuru botnet comprises a globally-dispersed collection of hacked IoT devices, including routers, digital video recorders and other systems that are commandeered via default passwords or software vulnerabilities. As documented by researchers at QiAnXin XLab, the botnet was first identified in an August 2024 attack on a large gaming platform.

Aisuru reportedly went quiet after that exposure, only to reappear in November with even more firepower and software exploits. In a January 2025 report, XLab found the new and improved Aisuru (a.k.a. “Airashi“) had incorporated a previously unknown zero-day vulnerability in Cambium Networks cnPilot routers.

NOT FORKING AROUND

The people behind the Aisuru botnet have been peddling access to their DDoS machine in public Telegram chat channels that are closely monitored by multiple security firms. In August 2024, the botnet was rented out in subscription tiers ranging from $150 per day to $600 per week, offering attacks of up to two terabits per second.

“You may not attack any measurement walls, healthcare facilities, schools or government sites,” read a notice posted on Telegram by the Aisuru botnet owners in August 2024.

Interested parties were told to contact the Telegram handle “@yfork” to purchase a subscription. The account @yfork previously used the nickname “Forky,” an identity that has been posting to public DDoS-focused Telegram channels since 2021.

According to the FBI, Forky’s DDoS-for-hire domains have been seized in multiple law enforcement operations over the years. Last year, Forky said on Telegram he was selling the domain stresser[.]best, which saw its servers seized by the FBI in 2022 as part of an ongoing international law enforcement effort aimed at diminishing the supply of and demand for DDoS-for-hire services.

“The operator of this service, who calls himself ‘Forky,’ operates a Telegram channel to advertise features and communicate with current and prospective DDoS customers,” reads an FBI seizure warrant (PDF) issued for stresser[.]best. The FBI warrant stated that on the same day the seizures were announced, Forky posted a link to a story on this blog that detailed the domain seizure operation, adding the comment, “We are buying our new domains right now.”

Approximately ten hours later, Forky posted again, including a screenshot of the stresser[.]best user dashboard, instructing customers to use their saved passwords for the old website on the new one.

A review of Forky’s posts to public Telegram channels — as indexed by the cyber intelligence firms Unit 221B and Flashpoint — reveals a 21-year-old individual who claims to reside in Brazil [full disclosure: Flashpoint is currently an advertiser on this blog].

Since late 2022, Forky’s posts have frequently promoted a DDoS mitigation company and ISP that he operates called botshield[.]io. The Botshield website is connected to a business entity registered in the United Kingdom called Botshield LTD, which lists a 21-year-old woman from Sao Paulo, Brazil as the director. Internet routing records indicate Botshield (AS213613) currently controls several hundred Internet addresses that were allocated to the company earlier this year.

Domaintools.com reports that botshield[.]io was registered in July 2022 to a Kaike Southier Leite in Sao Paulo. A LinkedIn profile by the same name says this individual is a network specialist from Brazil who works in “the planning and implementation of robust network infrastructures, with a focus on security, DDoS mitigation, colocation and cloud server services.”

MEET FORKY

In his posts to public Telegram chat channels, Forky has hardly attempted to conceal his whereabouts or identity. In countless chat conversations indexed by Unit 221B, Forky could be seen talking about everyday life in Brazil, often remarking on the extremely low or high prices in Brazil for a range of goods, from computer and networking gear to narcotics and food.

Reached via Telegram, Forky claimed he was “not involved in this type of illegal actions for years now,” and that the project had been taken over by other unspecified developers. Forky initially told KrebsOnSecurity he had been out of the botnet scene for years, only to concede this wasn’t true when presented with public posts on Telegram from late last year that clearly showed otherwise.

Forky denied being involved in the attack on KrebsOnSecurity, but acknowledged that he helped to develop and market the Aisuru botnet. Forky claims he is now merely a staff member for the Aisuru botnet team, and that he stopped running the botnet roughly two months ago after starting a family. Forky also said the woman named as director of Botshield is related to him.

Forky offered equivocal, evasive responses to a number of questions about the Aisuru botnet and his business endeavors. But on one point he was crystal clear:

“I have zero fear about you, the FBI, or Interpol,” Forky said, asserting that he is now almost entirely focused on their hosting business — Botshield.

Forky declined to discuss the makeup of his ISP’s clientele, or to clarify whether Botshield was more of a hosting provider or a DDoS mitigation firm. However, Forky has posted on Telegram about Botshield successfully mitigating large DDoS attacks launched against other DDoS-for-hire services.

DomainTools finds the same Sao Paulo street address in the registration records for botshield[.]io was used to register several other domains, including cant-mitigate[.]us. The email address in the WHOIS records for that domain is forkcontato@gmail.com, which DomainTools says was used to register the domain for the now-defunct DDoS-for-hire service stresser[.]us, one of the domains seized in the FBI’s 2023 crackdown.

On May 8, 2023, the U.S. Department of Justice announced the seizure of stresser[.]us, along with a dozen other domains offering DDoS services. The DOJ said ten of the 13 domains were reincarnations of services that were seized during a prior sweep in December, which targeted 48 top stresser services (also known as “booters”).

Forky claimed he could find out who attacked my site with Aisuru. But when pressed a day later on the question, Forky said he’d come up empty-handed.

“I tried to ask around, all the big guys are not retarded enough to attack you,” Forky explained in an interview on Telegram. “I didn’t have anything to do with it. But you are welcome to write the story and try to put the blame on me.”

THE GHOST OF MIRAI

The 6.3 Tbps attack last week caused no visible disruption to this site, in part because it was so brief — lasting approximately 45 seconds. DDoS attacks of such magnitude and brevity typically are produced when botnet operators wish to test or demonstrate their firepower for the benefit of potential buyers. Indeed, Google’s Menscher said it is likely that both the May 12 attack and the slightly larger 6.5 Tbps attack against Cloudflare last month were simply tests of the same botnet’s capabilities.

In many ways, the threat posed by the Aisuru/Airashi botnet is reminiscent of Mirai, an innovative IoT malware strain that emerged in the summer of 2016 and successfully out-competed virtually all other IoT malware strains in existence at the time.

As first revealed by KrebsOnSecurity in January 2017, the Mirai authors were two U.S. men who co-ran a DDoS mitigation service — even as they were selling far more lucrative DDoS-for-hire services using the most powerful botnet on the planet.

Less than a week after the Mirai botnet was used in a days-long DDoS against KrebsOnSecurity, the Mirai authors published the source code to their botnet so that they would not be the only ones in possession of it in the event of their arrest by federal investigators.

Ironically, the leaking of the Mirai source is precisely what led to the eventual unmasking and arrest of the Mirai authors, who went on to serve probation sentences that required them to consult with FBI investigators on DDoS investigations. But that leak also rapidly led to the creation of dozens of Mirai botnet clones, many of which were harnessed to fuel their own powerful DDoS-for-hire services.

Menscher told KrebsOnSecurity that as counterintuitive as it may sound, the Internet as a whole would probably be better off if the source code for Aisuru became public knowledge. After all, he said, the people behind Aisuru are in constant competition with other IoT botnet operators who are all striving to commandeer a finite number of vulnerable IoT devices globally.

Such a development would almost certainly cause a proliferation of Aisuru botnet clones, he said, but at least then the overall firepower from each individual botnet would be greatly diminished — or at least within range of the mitigation capabilities of most DDoS protection providers.

Barring a source code leak, Menscher said, it would be nice if someone published the full list of software exploits being used by the Aisuru operators to grow their botnet so quickly.

“Part of the reason Mirai was so dangerous was that it effectively took out competing botnets,” he said. “This attack somehow managed to compromise all these boxes that nobody else knows about. Ideally, we’d want to see that fragmented out, so that no [individual botnet operator] controls too much.”