Chinese hacker hits over 100 company websites using AI agents — Deere and SharkNinja among top brands affected in attack

A hacker used AI agents to target more than 1,200 websites, compromising over 100 in under a month Autonomous agents tested vulnerabilities, adapted tactics, and established access with minimal human input Researchers warn AI-powered attacks are making large-scale website compromise faster and cheaper In less than a month, a single Chinese hacker managed to break into more than 100 company websites, while doing almost none of the work himself.

Instead, he tasked AI agents to do it for him and paid them around $5,000 in tokens for the job.

The campaign was spotted by cybersecurity researcher Snorre Fagerland from NorForge, who was looking for exposed Cairn installations when he found approximately two dozen being used for malicious purposes.

These gave him first-hand insight into an active cybercriminal operation.

Cairn is described as an open source, general-purpose AI problem-solving engine, designed to help autonomous agents find solutions to complex tasks.

Instead of focusing on a single application, Cairn provides a framework that defines goals, explores different approaches, and then executes actions to try and solve the problem.

According to numerous media outlets, Cairn is quite popular in the cybercriminal community (although it’s not malicious by design).

When security becomes a problem needing solving In this case, the “problem” Cairn was trying to solve for the attacker was how to run code on a website without signing in.

They were trying out SQL injection, file uploads, as well as unsafe handling of stored objects.

The goal, according to the researcher, was to establish persistent access to shopping and payment systems which could later be used to steal money.

Fagerland said the attacker used a combination of models, likely Claude Code with a DeepSeek model, although it is very difficult to determine.

The instructions themselves were very brief, generally fewer than 100 Chinese characters, and in less than a month, the agents tried to break into more than 1,200 sites.

On average, the agents poke around a website for a day (23 hours), before either breaking in or moving on.

With some 100 successful break-ins, Fagerland says the hacker paid $50 for tokens on average, per breach.