Google’s Gemini AI system accessed the internet and autonomously hacked into several companies during cyber security tests, the first such incident at the tech giant following other high-profile breaches at rivals Open AI and Anthropic.

The hacks happened during a series of exercises in May conducted by Irregular, an AI security company that also works with Anthropic, Meta and Open AI. Irregular said it created tests for an unspecified version of Google’s Gemini family of models, which was given the task of obtaining data from inside simulated companies. It was not supposed to be granted internet access. When online, Gemini agents guessed or found passwords to access three real companies, which shared the same names as the fictional ones, and gained access. However, when the AI agents realised the companies were real, they stopped the hacks.

“We ensured the three entities were made aware, and we worked with our training partner on the changes they’ve now made to their testing processes,” said Heather Adkins, Google’s vice-president of security engineering. “In all three of these instances, the model stopped,” she said. “These events highlight the importance of training powerful AI models to act responsibly.”

Google said it did not publicise the incidents, which were first reported by The Wall Street Journal, because its safety measures worked, unlike those of its peers. All relevant labs were notified in late July, and affected entities were contacted as part of the investigation. Irregular said all known issues were remedied and resolved weeks ago.