Arrests in Western Australia
Australian Federal Police have arrested two men in Western Australia, aged 21 and 23, believed to be key figures in the notorious cybercrime group TeamPCP. The group is blamed for one of the longest-running software supply chain attack sprees ever recorded.
The arrests happened Wednesday morning. The AFP says the pair face a combined 14 cybercrime offenses and appeared in Perth Magistrates Court today.
While the AFP hasn’t named the defendants, reporting from KrebsOnSecurity has identified them as Ruben Ian Thomson of Cottesloe and Michael Gaebler. Thomson was denied bail; Gaebler’s attorney reportedly didn’t request it. Both remain in custody until September 18.
Who is TeamPCP?
TeamPCP burst onto the scene in late 2025, embedding malicious code in hundreds of open source tools and extorting victims. Their self-propagating worm, dubbed Shai-Hulud, compromised corporate cloud environments by hijacking developer credentials on platforms like GitHub and NPM.
The group’s tactic was cyclical. They’d compromise a developer’s machine, steal credentials, publish malicious versions of dev tools, and repeat. This allowed them to expand their network of breached systems exponentially.
In March, they hit AI infrastructure by compromising LiteLLM, an open source AI gateway. The attack harvested cloud keys from over 2,500 organizations. By May, they claimed responsibility for compromising at least 3,800 GitHub repositories.
The Cybercats Connection
Security experts describe TeamPCP less as a structured gang and more as a loose amalgamation of threat actors. Austin Larsen, a principal threat analyst at Google Threat Intelligence Group, calls it “a peer community of individually-skilled actors, with one clear center of gravity.”
That center was a Matrix chat server called “Cybercats,” created by security researcher George Prepakis, who operates the X profile @kernelstub. The server became a meeting ground for multiple cybercrime entities, including TeamPCP.
Several administrators used their X handles in these chats, often taunting victims publicly before news broke. The handle @pcpcasper, for instance, was linked to Michael Gaebler, who had an extensive message history on Telegram showing active membership in the National Socialist Network, an Australian neo-Nazi group.
How the Leader Was Unmasked
The TeamPCP spokesperson, known by various aliases including EllisD25, BulkDMT, and Express, made critical operational security mistakes that led to his identification.
Investigators traced email addresses and IP addresses across multiple forums. A Gmail account linked to the handle ChristmasSnow on Raidforums led to IP addresses in Perth, Australia. Passive DNS records tied one of those IPs to a family with the last name Thomson.
Further digging connected the dots to Ruben Thomson. His brother’s accounts, his own HackerOne profile (under the username Deadcatx3, an alias flagged by multiple security firms), and even a company he incorporated named “OPSEC Express” — a nod to his Breachforums nickname — all pointed to the same person.
In an interview with KrebsOnSecurity, the TeamPCP leader, who goes by Ellis, was remarkably open. He claimed to have earned only about $20,000 from his activities. “Blackhatting is fun,” he said. “There are actual rewards and incentives to learn and you grow with your team.”
Ellis expressed no remorse, saying, “If I’ve already been found out then it’s out of my control, I’ll make peace with that.” He also acknowledged his struggles with addiction, noting that “someone like me needs a lot of help that prison just can’t provide.”
Implications for Supply Chain Security
Charlie Eriksen, a security researcher at Aikido Security, says TeamPCP represents a new kind of threat actor. “They are not a state actor, not quite organized cybercrime, and not purely ideological,” he told KrebsOnSecurity.
Eriksen argues that large language models have compressed the gap between understanding an attack technique and executing it at scale. This allows less experienced actors to cause significant damage without the operational discipline of professional groups.
“They can be noisy, they can make mistakes,” he said. “They can leave evidence everywhere. They can take risks that a professional criminal group or intelligence service would consider completely unacceptable.”
Paradoxically, TeamPCP may have done the security community a favor. Their success forced GitHub to introduce a three-day “cooldown” mechanism for Dependabot, its auto-update tool. This gives security tools time to identify compromised packages before they spread. Python and various JavaScript platforms have also adopted similar measures.
“They managed to wake up Microsoft to the fact that they had become negligent in terms of security,” Eriksen said. “They humiliated Microsoft into action.”
The arrests of Thomson and Gaebler send a clear message: even the most brazen cybercriminals can be caught. But the underlying vulnerabilities in open source ecosystems remain. The cooldown periods are a start, but the broader community still has work to do.
For more on how to protect your organization from similar threats, check out our guide on open source security best practices. You might also be interested in how to secure your GitHub repositories against credential theft.