Hacker's AI agents breached 100+ sites at $50 each, NorForge says

A Chinese-speaking hacker broke into websites belonging to more than 100 companies while leaving nearly all the work to AI agents, according to a Reuters exclusive published Monday.

Snorre Fagerland, principal threat researcher at NorForge, said he watched the agents attempt more than 1,200 sites across the US, Canada, Australia and Japan starting September 25. The named victims he confirmed to Reuters are farm equipment maker Deere, home appliance company SharkNinja and engine manufacturer Cummins. Each successful intrusion took the agents roughly 23 hours. Fagerland put the full bill at about $5,000 in tokens, or roughly $50 per successful hack.

The operator wrote their instructions in fewer than 100 Chinese characters: find a way to run code on each site, then plant an uploader web shell. From there the agents worked unsupervised. Fagerland had assumed hacking agents would still need a human looking over their shoulder; this campaign showed otherwise.

The campaign ran on Cairn, an open-source AI problem-solving platform popular with hackers that coordinates agents to probe a target, search for weaknesses and attempt entry. Fagerland found it after scanning the web for inadvertently exposed Cairn panels; by around October 2 he had identified about two dozen such instances being used for malicious activity. All of the operator's tasks ran under a worker named claudecode_deepseek-v4.1-flash, which NorForge reads as Anthropic's Claude Code calling DeepSeek's low-cost V4.1 Flash model, as The Next Web summarized.

"It's not script kiddie stuff," Fagerland told Reuters.

The disclosure lands in the middle of a busy stretch for AI cybersecurity coverage on our tracker, the same week Microsoft rolled out Guardian Agents that explicitly treat AI agents as insider threats.