AI Coding Agents Are Installing Unknown/Untrusted Code on Corporate Networks
Researchers found 120 corporate llms.txt files pointing to unregistered packages, demonstrating AI coding agents install and execute attacker-controlled code on Fortune 500 networks.
Researchers at an Israeli stealth startup scanned 6,214 live domains belonging to defense contractors, Fortune 500 and Big Tech companies, finding 120 llms.txt files that pointed to unregistered code packages or domain names. After registering a handful of the unclaimed names, they received a phone-home beacon within an hour from a Fortune 500 company and dozens more over time. Parent-process chains showed coding agents including Claude, OpenAI's Codex and Nous Research's Hermes executed the installed packages. The researchers warn agents treating vendor docs as ground truth creates a SolarWinds-style supply-chain surface as agent adoption spreads across SaaS, cloud and endpoints.
- Scanned 6,214 domains of defense contractors, Fortune 500 and Big Tech firms
- 120 llms.txt files pointed to unregistered packages or domain names
- Registered names drew phone-home beacons within an hour from a Fortune 500 firm
- Claude, OpenAI Codex and Nous Research Hermes were involved in the installs
- Researchers warn of SolarWinds-style supply-chain attacks as agents multiply
Full article283 words · extracted from schneier.com · click to collapse
We cannot forget that AI coding agents are not yet trustworthy:
Researchers at a stealth startup in Israel scanned 6,214 live domains belonging to defense contractors, Fortune 500, and Big Tech companies. Of the 8,265 llms.txt and llms-full.txt files they found (many sites hosted both an llms.txt and an llms-full.txt file), 120 of them, each on a different site, pointed to one or more code packages or domain names that weren’t registered. To test what happens when an AI agent processes such files, the researchers registered a handful of the unclaimed names and hosted packages that caused any machine executing them to reach out to their server. Within an hour, the researchers received a phone-home response from a Fortune 500 company. Over time, they got a few dozen more, some from more Fortune 500 companies and others from startups. Their beacon also recorded the chain of parent processes that spawned each install, ultimately revealing that coding agents, including Claude, OpenAI’s Codex, and Nous Research’s Hermes, were involved. Anthropic, OpenAI, and Nous Research did not respond to requests for comment by the time of publication.
This kind of thing will be exploited. Think Solar Winds–style supply chain attacks.
“The trust model is broken,” Alon Hertz, one of the researchers, wrote in an interview. “Agents treat vendor docs as ground truth and don’t question themand neither do the humans supervising them. Agentic AI usage is exploding, and agents are spreading across every layerSaaS, cloud, endpoint. As they multiply, so does the supply-chain surface, and today’s guards don’t cover it.”
Sidebar photo of Bruce Schneier by Joe MacInnis.
Text extracted automatically; images, tables and formatting may be missing. Original: https://www.schneier.com/blog/archives/2026/09/ai-coding-agents-are-installing-unknown-untrusted-code-on-corporate-networks.html