The Federal Bureau of Investigation (FBI) said today it worked with industry partners to seize hundreds of domains associated with NetNut, a sprawling residential proxy service operated by the publicly-traded Israeli company Alarum Technologies [NASDAQ: ALAR]. The action comes roughly two weeks after KrebsOnSecurity published findings from multiple security firms connecting NetNut to the Popa botnet, a collection of at least two million devices that have been compromised by malicious software with little or no consent from victims.

The NetNut homepage today was replaced by this seizure banner from the FBI.

On June 19, three different security firms issued similar findings: That NetNut is a residential proxy network which populates a botnet called Popa, and distributes software for devices commonly found in homes, such as smart TVs and streaming boxes. NetNut’s software turns those systems into always-on residential proxy nodes that are rented to others, who predominantly use them to relay abusive and intrusive Internet traffic, such as mass content scraping, advertising fraud, and account takeover activity.

Earlier today, NetNut’s homepage was replaced with a seizure notice from the FBI and the Internal Revenue Service Criminal Investigation division. The seizure notice thanked Google, Lumen, Shadowserver and other industry partners for their help in dismantling hundreds of domains tied to the Popa botnet, which experts say has long been synonymous with NetNut’s residential proxy infrastructure.

In a blog post published today, the Google Threat Intelligence Group (GTIG) said NetNut’s proxy network is widely resold and white-labeled by a number of third-party proxy providers, and that its services are heavily sought out by cybercriminals seeking to obfuscate the source of their malicious traffic. The GTIG said that in a single week during June 2026, they observed 316 distinct clusters of threat actors using suspected NetNut exit nodes, including cybercriminal and espionage groups.

“These bad actors can use NetNut to mask their origin IP address when accessing victim environments, accessing their own infrastructure, and conducting password spray attacks,” Google’s GTIG wrote. “Furthermore, when a consumer device becomes an exit node, unauthorized network traffic passes through it. This means bad actors can access other private devices on the same home network, effectively exposing them to Internet threats.”

Google said it disabled Google accounts and services used by NetNut for malware command and control, and that it shared technical intelligence on NetNut’s software development kits (SDKs) and backend infrastructure with platform providers, law enforcement and research firms. The company also disabled apps known to bundle NetNut’s various SDKs.

Omer Weiss, legal counsel for NetNut parent Alarum Technologies, said the company was aware of the FBI seizure and cooperating with investigators.

“Alarum takes this matter seriously and will fully cooperate with law enforcement to ensure any misuse of its infrastructure is thoroughly investigated and those responsible are held to account,” Weiss said in a written statement.

Benjamin Brundage is founder of the proxy tracking service Synthient, one of the companies that published evidence last month linking the Popa botnet to NetNut and Alarum Technologies. Brundage said the domain seizures appear to have disrupted both the Popa botnet and the NetNut proxy network that rides on top of it.

Brundage said NetNut’s apparent demise is likely to be a great disadvantage for the cybercrime community, which was already reeling from legal actions by Google earlier this year that seized infrastructure for NetNut’s biggest competitor — IPIDEA.

“I think this takedown is going to have a big impact, because NetNut gained significant popularity after the IPIDEA takedown,” he said. “Also NetNut has been incredibly common among resellers, and they were on par with IPIDEA in terms of their daily traffic, quality, size, price per gigabyte, all of it.”

NetNut’s infrastructure, in a nutshell. Image: Black Lotus Labs, Lumen.

The NetNut and Popa botnet takedown may have another added benefit, Brundage said: Lessening the impact of large distributed denial-of-service botnets that have been built on the backs of poorly configured residential proxy services. In January, Synthient revealed how cybercriminals had built the world’s largest DDoS botnet (Kimwolf) by tunneling through IPIDEA proxy connections into the local networks of TV box owners, and infecting other Android-based devices behind the victim’s firewall.

While many of the bigger proxy providers took steps to block this activity, resellers of the major proxy networks have been far slower to respond to the threat, Brundage said.

“In terms of all these TV box devices getting compromised from the proxy network, it will have an impact on the DDoS botnets out there,” he said.

For its part, Google reckons today’s actions have caused “significant degradation to NetNut’s proxy network and its business operations, reducing the available pool of devices for the proxy operator by millions.” But the company warns that proxy networks can rebuild themselves by effectively reselling other proxy services, as IPIDEA has done over the past few months.

“Google has high confidence that many popular residential proxy brands are in fact whitelabeling the NetNut botnet,” the GTIG report concludes. “While we expect this disruption to have a larger ripple effect across the residential proxy ecosystem, observations after the disruption of IPIDEA proved that individual networks can appear resilient. What we have observed is that when faced with the degradation of their own botnet, proxy operators begin buying capacity from their competitors, effectively becoming a reseller. We recognize that creating a lasting disruption in this fluid ecosystem means we must scale our efforts to target the infrastructure of several interconnected providers.”

As KrebsOnSecurity has warned repeatedly, most of the no-name TV streaming boxes for sale on the major e-commerce websites either come pre-installed with residential proxy software, or require the installation of proxy SDKs in order to use the device for its stated purpose (streaming pirated movies, sporting events and TV shows). Google’s advice here is sound: When it comes to TV boxes, stick to name brands from reputable manufacturers, and then be sparing and judicious with any apps you choose to install.

The sketchy TV boxes that are being commandeered by the Popa botnet and other threats all come with or require the user to install unofficial Android operating systems that do not operate within the confines of Google’s Official Play Protect store. Google says consumers can confirm whether or not a device is built with the official Android TV OS and Play Protect certification by following these instructions.

Even people without TV streaming boxes can find their smart TVs enrolled in residential proxy networks, just by installing one of thousands of apps available for download on Samsung and LG smart TVs. In a report released last month, the proxy tracking company Spur found 42 percent of apps available for download via the webOS operating system on LG smart TVs include SDKs that turn one’s television into an always-on residential proxy node. More than a quarter of the apps made for Samsung’s Tizen operating system had similar residential proxy components, Spur found.

Image: Spur.us.

Update, 4:24 p.m. ET: Included a statement shared post-publication from an attorney representing NetNut parent Alarum Technologies.

Update, July 8, 2:34 p.m. ET: The website for Alarum Technologies — alarum[.]io — now also features a seizure notice from the FBI. The company’s stock has taken a beating since the FBI action, and is currently trading at $2.62 a share, a roughly 67 percent decline over the past week.

For the past week, the massive “Internet of Things” (IoT) botnet known as Kimwolf has been disrupting The Invisible Internet Project (I2P), a decentralized, encrypted communications network designed to anonymize and secure online communications. I2P users started reporting disruptions in the network around the same time the Kimwolf botmasters began relying on it to evade takedown attempts against the botnet’s control servers.

Kimwolf is a botnet that surfaced in late 2025 and quickly infected millions of systems, turning poorly secured IoT devices like TV streaming boxes, digital picture frames and routers into relays for malicious traffic and abnormally large distributed denial-of-service (DDoS) attacks.

I2P is a decentralized, privacy-focused network that allows people to communicate and share information anonymously.

“It works by routing data through multiple encrypted layers across volunteer-operated nodes, hiding both the sender’s and receiver’s locations,” the I2P website explains. “The result is a secure, censorship-resistant network designed for private websites, messaging, and data sharing.”

On February 3, I2P users began complaining on the organization’s GitHub page about tens of thousands of routers suddenly overwhelming the network, preventing existing users from communicating with legitimate nodes. Users reported a rapidly increasing number of new routers joining the network that were unable to transmit data, and that the mass influx of new systems had overwhelmed the network to the point where users could no longer connect.

I2P users complaining about service disruptions from a rapidly increasing number of routers suddenly swamping the network.

When one I2P user asked whether the network was under attack, another user replied, “Looks like it. My physical router freezes when the number of connections exceeds 60,000.”

A graph shared by I2P developers showing a marked drop in successful connections on the I2P network around the time the Kimwolf botnet started trying to use the network for fallback communications.

The same day that I2P users began noticing the outages, the individuals in control of Kimwolf posted to their Discord channel that they had accidentally disrupted I2P after attempting to join 700,000 Kimwolf-infected bots as nodes on the network.

The Kimwolf botmaster openly discusses what they are doing with the botnet in a Discord channel with my name on it.

Although Kimwolf is known as a potent weapon for launching DDoS attacks, the outages caused this week by some portion of the botnet attempting to join I2P are what’s known as a “Sybil attack,” a threat in peer-to-peer networks where a single entity can disrupt the system by creating, controlling, and operating a large number of fake, pseudonymous identities.

Indeed, the number of Kimwolf-infected routers that tried to join I2P this past week was many times the network’s normal size. I2P’s Wikipedia page says the network consists of roughly 55,000 computers distributed throughout the world, with each participant acting as both a router (to relay traffic) and a client.

However, Lance James, founder of the New York City based cybersecurity consultancy Unit 221B and the original founder of I2P, told KrebsOnSecurity the entire I2P network now consists of between 15,000 and 20,000 devices on any given day.

An I2P user posted this graph on Feb. 10, showing tens of thousands of routers — mostly from the United States — suddenly attempting to join the network.

Benjamin Brundage is founder of Synthient, a startup that tracks proxy services and was the first to document Kimwolf’s unique spreading techniques. Brundage said the Kimwolf operator(s) have been trying to build a command and control network that can’t easily be taken down by security companies and network operators that are working together to combat the spread of the botnet.

Brundage said the people in control of Kimwolf have been experimenting with using I2P and a similar anonymity network — Tor — as a backup command and control network, although there have been no reports of widespread disruptions in the Tor network recently.

“I don’t think their goal is to take I2P down,” he said. “It’s more they’re looking for an alternative to keep the botnet stable in the face of takedown attempts.”

The Kimwolf botnet created challenges for Cloudflare late last year when it began instructing millions of infected devices to use Cloudflare’s domain name system (DNS) settings, causing control domains associated with Kimwolf to repeatedly usurp Amazon, Apple, Google and Microsoft in Cloudflare’s public ranking of the most frequently requested websites.

James said the I2P network is still operating at about half of its normal capacity, and that a new release is rolling out which should bring some stability improvements over the next week for users.

Meanwhile, Brundage said the good news is Kimwolf’s overlords appear to have quite recently alienated some of their more competent developers and operators, leading to a rookie mistake this past week that caused the botnet’s overall numbers to drop by more than 600,000 infected systems.

“It seems like they’re just testing stuff, like running experiments in production,” he said. “But the botnet’s numbers are dropping significantly now, and they don’t seem to know what they’re doing.”