One Hacker Used AI Agents to Breach 100+ Company Websites for About $5,000

NorForge, a threat-intelligence firm, said a Chinese-speaking operator used autonomous AI agents through the open-source Cairn platform to target more than 1,200 websites beginning September 25, 2026. The agents reportedly compromised sites associated with more than 100 companies, primarily in the United States, Canada, Australia and Japan. Reuters reviewed attacker records and identified Deere, SharkNinja and Cummins among the affected companies; the amount of data taken, if any, remains unknown. Cairn assigns goals to AI agents, which then pursue multistep tasks and post results to a shared board. In the reported campaign, short Chinese-language instructions directed agents to seek code-execution flaws and install web-shell uploaders. NorForge confirmed a live web shell at a hardware-parts vendor and confirmed a compromise at a large US retailer. One intrusion combined unauthorized write access to a memcached session store, unsafe deserialization of saved PHP objects and an older Zend Framework vulnerability. NorForge researcher Snorre Fagerland told Reuters the operation spent about $5,000 in tokens, or roughly $50 per successful intrusion, while NorForge estimated about $5 per task across successful, failed and abandoned attempts and an overall success rate near 10%. Exposed Cairn control panels revealed targets, vulnerabilities and credentials; TruffleHog identified hundreds of secrets, 11% of which remained valid. Deere and SharkNinja said they contained or remediated limited incidents, while Cummins said it was investigating a possible attack involving a vendor-operated website.