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Ukraine has seen nearly one-fifth of its Internet space come under Russian control or sold to Internet address brokers since February 2022, a new study finds. The analysis indicates large chunks of Ukrainian Internet address space are now in the hands of shadowy proxy and anonymity services that are nested at some of America’s largest Internet service providers (ISPs).
The findings come in a report examining how the Russian invasion has affected Ukraine’s domestic supply of Internet Protocol Version 4 (IPv4) addresses. Researchers at Kentik, a company that measures the performance of Internet networks, found that while a majority of ISPs in Ukraine haven’t changed their infrastructure much since the war began in 2022, others have resorted to selling swathes of their valuable IPv4 address space just to keep the lights on.
For example, Ukraine’s incumbent ISP Ukrtelecom is now routing just 29 percent of the IPv4 address ranges that the company controlled at the start of the war, Kentik found. Although much of that former IP space remains dormant, Ukrtelecom told Kentik’s Doug Madory they were forced to sell many of their address blocks “to secure financial stability and continue delivering essential services.”
“Leasing out a portion of our IPv4 resources allowed us to mitigate some of the extraordinary challenges we have been facing since the full-scale invasion began,” Ukrtelecom told Madory.
Madory found much of the IPv4 space previously allocated to Ukrtelecom is now scattered to more than 100 providers globally, particularly at three large American ISPs — Amazon (AS16509), AT&T (AS7018), and Cogent (AS174).
Another Ukrainian Internet provider — LVS (AS43310) — in 2022 was routing approximately 6,000 IPv4 addresses across the nation. Kentik learned that by November 2022, much of that address space had been parceled out to over a dozen different locations, with the bulk of it being announced at AT&T.
IP addresses routed over time by Ukrainian provider LVS (AS43310) shows a large chunk of it being routed by AT&T (AS7018). Image: Kentik.
Ditto for the Ukrainian ISP TVCOM, which currently routes nearly 15,000 fewer IPv4 addresses than it did at the start of the war. Madory said most of those addresses have been scattered to 37 other networks outside of Eastern Europe, including Amazon, AT&T, and Microsoft.
The Ukrainian ISP Trinity (AS43554) went offline in early March 2022 during the bloody siege of Mariupol, but its address space eventually began showing up in more than 50 different networks worldwide. Madory found more than 1,000 of Trinity’s IPv4 addresses suddenly appeared on AT&T’s network.
Why are all these former Ukrainian IP addresses being routed by U.S.-based networks like AT&T? According to spur.us, a company that tracks VPN and proxy services, nearly all of the address ranges identified by Kentik now map to commercial proxy services that allow customers to anonymously route their Internet traffic through someone else’s computer.
From a website’s perspective, the traffic from a proxy network user appears to originate from the rented IP address, not from the proxy service customer. These services can be used for several business purposes, such as price comparisons, sales intelligence, web crawlers and content-scraping bots. However, proxy services also are massively abused for hiding cybercrime activity because they can make it difficult to trace malicious traffic to its original source.
IPv4 address ranges are always in high demand, which means they are also quite valuable. There are now multiple companies that will pay ISPs to lease out their unwanted or unused IPv4 address space. Madory said these IPv4 brokers will pay between $100-$500 per month to lease a block of 256 IPv4 addresses, and very often the entities most willing to pay those rental rates are proxy and VPN providers.
A cursory review of all Internet address blocks currently routed through AT&T — as seen in public records maintained by the Internet backbone provider Hurricane Electric — shows a preponderance of country flags other than the United States, including networks originating in Hungary, Lithuania, Moldova, Mauritius, Palestine, Seychelles, Slovenia, and Ukraine.
AT&T’s IPv4 address space seems to be routing a great deal of proxy traffic, including a large number of IP address ranges that were until recently routed by ISPs in Ukraine.
Asked about the apparent high incidence of proxy services routing foreign address blocks through AT&T, the telecommunications giant said it recently changed its policy about originating routes for network blocks that are not owned and managed by AT&T. That new policy, spelled out in a February 2025 update to AT&T’s terms of service, gives those customers until Sept. 1, 2025 to originate their own IP space from their own autonomous system number (ASN), a unique number assigned to each ISP (AT&T’s is AS7018).
“To ensure our customers receive the best quality of service, we changed our terms for dedicated internet in February 2025,” an AT&T spokesperson said in an emailed reply. “We no longer permit static routes with IP addresses that we have not provided. We have been in the process of identifying and notifying affected customers that they have 90 days to transition to Border Gateway Protocol routing using their own autonomous system number.”
Ironically, the co-mingling of Ukrainian IP address space with proxy providers has resulted in many of these addresses being used in cyberattacks against Ukraine and other enemies of Russia. Earlier this month, the European Union sanctioned Stark Industries Solutions Inc., an ISP that surfaced two weeks before the Russian invasion and quickly became the source of large-scale DDoS attacks and spear-phishing attempts by Russian state-sponsored hacking groups. A deep dive into Stark’s considerable address space showed some of it was sourced from Ukrainian ISPs, and most of it was connected to Russia-based proxy and anonymity services.
According to Spur, the proxy service IPRoyal is the current beneficiary of IP address blocks from several Ukrainian ISPs profiled in Kentik’s report. Customers can chose proxies by specifying the city and country they would to proxy their traffic through. Image: Trend Micro.
Spur’s Chief Technology Officer Riley Kilmer said AT&T’s policy change will likely force many proxy services to migrate to other U.S. providers that have less stringent policies.
“AT&T is the first one of the big ISPs that seems to be actually doing something about this,” Kilmer said. “We track several services that explicitly sell AT&T IP addresses, and it will be very interesting to see what happens to those services come September.”
Still, Kilmer said, there are several other large U.S. ISPs that continue to make it easy for proxy services to bring their own IP addresses and host them in ranges that give the appearance of residential customers. For example, Kentik’s report identified former Ukrainian IP ranges showing up as proxy services routed by Cogent Communications (AS174), a tier-one Internet backbone provider based in Washington, D.C.
Kilmer said Cogent has become an attractive home base for proxy services because it is relatively easy to get Cogent to route an address block.
“In fairness, they transit a lot of traffic,” Kilmer said of Cogent. “But there’s a reason a lot of this proxy stuff shows up as Cogent: Because it’s super easy to get something routed there.”
Cogent declined a request to comment on Kentik’s findings.
The U.S. Department of the Treasury today unveiled sanctions against three Chinese nationals for allegedly operating 911 S5, an online anonymity service that for many years was the easiest and cheapest way to route one’s Web traffic through malware-infected computers around the globe. KrebsOnSecurity identified one of the three men in a July 2022 investigation into 911 S5, which was massively hacked and then closed ten days later.
The 911 S5 botnet-powered proxy service, circa July 2022.
From 2015 to July 2022, 911 S5 sold access to hundreds of thousands of Microsoft Windows computers daily, as “proxies” that allowed customers to route their Internet traffic through PCs in virtually any country or city around the globe — but predominantly in the United States.
911 built its proxy network mainly by offering “free” virtual private networking (VPN) services. 911’s VPN performed largely as advertised for the user — allowing them to surf the web anonymously — but it also quietly turned the user’s computer into a traffic relay for paying 911 S5 customers.
911 S5’s reliability and extremely low prices quickly made it one of the most popular services among denizens of the cybercrime underground, and the service became almost shorthand for connecting to that “last mile” of cybercrime. Namely, the ability to route one’s malicious traffic through a computer that is geographically close to the consumer whose stolen credit card is about to be used, or whose bank account is about to be emptied.
In July 2022, KrebsOnSecurity published a deep dive into 911 S5, which found the people operating this business had a history of encouraging the installation of their proxy malware by any means available. That included paying affiliates to distribute their proxy software by secretly bundling it with other software.
A cached copy of flashupdate dot net, a pay-per-install affiliate program that incentivized the silent installation of 911’s proxy software.
That story named Yunhe Wang from Beijing as the apparent owner or manager of the 911 S5 proxy service. In today’s Treasury action, Mr. Wang was named as the primary administrator of the botnet that powered 911 S5.
“A review of records from network infrastructure service providers known to be utilized by 911 S5 and two Virtual Private Networks (VPNs) specific to the botnet operation (MaskVPN and DewVPN) showed Yunhe Wang as the registered subscriber to those providers’ services,” reads the Treasury announcement.
Update, May 29, 12:26 p.m. ET: The U.S. Department of Justice (DOJ) just announced they have arrested Wang in connection with the 911 S5 botnet. The DOJ says 911 S5 customers have stolen billions of dollars from financial institutions, credit card issuers, and federal lending programs.
“911 S5 customers allegedly targeted certain pandemic relief programs,” a DOJ statement on the arrest reads. “For example, the United States estimates that 560,000 fraudulent unemployment insurance claims originated from compromised IP addresses, resulting in a confirmed fraudulent loss exceeding $5.9 billion. Additionally, in evaluating suspected fraud loss to the Economic Injury Disaster Loan (EIDL) program, the United States estimates that more than 47,000 EIDL applications originated from IP addresses compromised by 911 S5. Millions of dollars more were similarly identified by financial institutions in the United States as loss originating from IP addresses compromised by 911 S5.”
The sanctions say Jingping Liu was Yunhe Wang’s co-conspirator in the laundering of criminally derived proceeds generated from 911 S5, mainly virtual currency. The government alleges the virtual currencies paid by 911 S5 users were converted into U.S. dollars using over-the-counter vendors who wired and deposited funds into bank accounts held by Liu.
“Jingping Liu assisted Yunhe Wang by laundering criminally derived proceeds through bank accounts held in her name that were then utilized to purchase luxury real estate properties for Yunhe Wang,” the document continues. “These individuals leveraged their malicious botnet technology to compromise personal devices, enabling cybercriminals to fraudulently secure economic assistance intended for those in need and to terrorize our citizens with bomb threats.”
The third man sanctioned is Yanni Zheng, a Chinese national the U.S. Treasury says acted as an attorney for Wang and his firm — Spicy Code Company Limited — and helped to launder proceeds from the business into real estate holdings. Spicy Code Company was also sanctioned, as well as Wang-controlled properties Tulip Biz Pattaya Group Company Limited, and Lily Suites Company Limited.
Ten days after the July 2022 story here on 911 S5, the proxy network abruptly closed up shop, citing a data breach that destroyed key components of its business operations.
In the months that followed, however, 911 S5 would resurrect itself under a different name: Cloud Router. That’s according to spur.us, a U.S.-based startup that tracks proxy and VPN services. In February 2024, Spur published research showing the Cloud Router operators reused many of the same components from 911 S5, making it relatively simple to draw a connection between the two.
The Cloud Router homepage, which according to Spur has been unreachable since this past weekend.
Spur found that Cloud Router was being powered by a new VPN service called PaladinVPN, which made it much more explicit to users that their Internet connections were going to be used to relay traffic for others. At the time, Spur found Cloud Router had more than 140,000 Internet addresses for rent.
Spur co-founder Riley Kilmer said Cloud Router appears to have suspended or ceased operations sometime this past weekend. Kilmer said the number of proxies advertised by the service had been trending downwards quite recently before the website suddenly went offline.
Cloud Router’s homepage is currently populated by a message from Cloudflare saying the site’s domain name servers are pointing to a “prohibited IP.”
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