As if the Miasma situation weren't bad enough, now this weapon is spreading like wildfire. Someone open sourced the entire Miasma worm supply-chain attack toolkit, likely using previously compromised developers' accounts to publish GitHub repositories containing the self-spreading malware’s source code over the last 24 hours. SafeDep, a company focused on open source supply chain security that developed Package Management Guard (PMG), spotted the malicious repos, named “Miasma-Open-Source-Release,” and said that they started appearing on Monday. Its researchers analyzed one of these before GitHub nixed it, and described the code as more than just a supply chain worm. “It is a full supply chain attack toolkit that allows the operator to execute various attacks via stolen credentials against arbitrary or targeted packages on public registries (PyPI, npm, RubyGems), JFrog Artifactory, GitHub repositories and GitHub Actions, AI coding tools config poisoning, SSH based lateral movement and other attack vectors,” the SafeDep team said. While we don’t know who is behind this publicly released worm, it follows in the footsteps of TeamPCP, which developed and then open sourced the mini Shai-Hulud worm last month, announcing a supply-chain attack contest on BreachForums and spawning copycat open source package poisonings. One of these copycat worms, Miasma, first hit upwards of 100 Red Hat and Microsoft open source projects before spreading to other victims, with app-security firm Socket tracking 473 affected package artifacts as of Tuesday. “The Miasma repository is an evolution of the Mini Shai-Hulud toolkit, and was open-sourced June 8 via four previously compromised users,” Rami McCarthy, principal threat researcher at Wiz, told The Register. “Since we had already reversed the payload, this public release isn’t particularly useful for sophisticated defenders, and we haven't observed any opportunistic adoption of it yet.” This, he added, mimics what happened when TeamPCP open sourced mini Shai-Hulud last month. “We didn't see attackers weaponize it either,” McCarthy said. “It's not clear [whether] attackers benefit from adopting this out-of-the-box toolkit versus vibe coding their own. And while it raises concerns about muddying attribution, attackers tend to continue developing their private fork of the malware, providing a clear payload progression to track and deconflict from anyone utilizing the open-source version.” An interesting aspect of both of these worms and other recent attacks like this one dubbed “Comment-and-Control” by AI bug hunter Aonan Guan is that they run entirely in GitHub - they don’t require any custom command-and-control (C2) infrastructure - and use the code-hosting platform for all stages of the attack including remote command execution, configuration, and data exfiltration. “This is a key behavioural shift because traditional network based detection and protection tools rely on baselining and anomaly detection,” SafeDep researchers noted. “Defenders now have to operate closer to application protocol to identify behavioural anomaly instead of network based anomalies.” The Miasma worm uses three independent GitHub commit search channels for C2, and each has a different search string and purpose. One of these, "DontRevokeOrItGoesBoom," discovers attacker-controlled personal access tokens (PATs) to exfiltrate credentials and other sensitive data. These PATs are AES-256-CBC encrypted in the commit message. The second, "TheBeautifulSandsOfTime," delivers JavaScript for immediate command execution. It’s checked once at startup, and, after validation, it passes the payload to eval() to execute at runtime. Finally, “firedalazer” delivers Python script URLs for the persistent monitor. All three are unauthenticated by default, use GitHub’s public commit search API, and use a different validation or decryption key, which means compromising one doesn’t automatically compromise the other two.®
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