Spain says it has seen first AI agent hack
Spanish data authorities warns organisations to step up their security as AI attacks were no longer a "theoretical risk"
Spain has seen its first official data breach due to an AI agent.
The Spanish Data Protection Agency said in a blog post that it had received the first notification of a data breach that was apparently carried out by an AI agent using a known large language model (LLM).
The revelation comes amid a wider discussion about the safety of AI, in particular agents, following a series of incidents in which OpenAI and Anthropic agents went "rogue" and targeted external organisations during evaluation tests. OpenAI admitted in July that its agents infiltrated the Hugging Face repository, and Anthropic followed suit shortly afterwards with its own admission of misaligned behaviour.
Francisco Pérez Bes, the head of the Agencia Espanola Proteccion Datos (AEPD), said in a blog post that the information on the attack comes entirely via the impacted organisation, with further investigation required.
But what it does show is that agentic AI attacks "have ceased to be a theoretical risk," Pérez Bes said, according to an automatically translated version of the blog post.
While AI has long been used to write phishing messages, translate fraudulent campaigns, and help search for flaws to exploit, Pérez Bes said the "emergence of AI agents... introduces a qualitative change," as it can plan tasks, execute code, and modify its actions autonomously.
He added: "It's important to remember that AI doesn't create new threats. But it does increase the speed, scale, and adaptability of existing malicious techniques, reducing the time available to detect and contain them.
Sign up today and you will receive a free copy of our Future Focus 2026 report - the leading resource for IT decision-maker insight on priorities and investment areas in AI, security and more.
His comments echo warnings from the security industry, with Forescout saying earlier this year that AI is now a "standard part of the attacker toolkit" and Anthropic adding that AI is helping to lower the bar for hackers.
What happened?
According to the blog post, the hackers managed to log into the compromised system, setting loose an autonomous agent to look for vulnerabilities in the application, which then allowed them to modify personal data and access invoices.
Pérez Bes stressed that there was no indication that the AI model used or its infrastructure had been compromised, and that the agent used wasn't necessarily designed to carry out such activities.
The victim of the attack hasn't been revealed, nor has the maker of the LLM itself – or any details on the hackers responsible.
What next?
Pérez Bes said the purpose of issuing the notification was to warn organizations to boost their security practices to answer the new threat of AI agents, calling it a sign to act.
"The arrival of AI agents in the offensive arena should prompt an immediate review of security and data protection models," he said, according to the translated post.
He called for organizations to include AI-assisted or AI-driven attacks in their risk analysis, reconsider response times as procedures designed for manual attacks won't be able to keep pace with autonomous agents, and to take measures to protect digital identities and credentials to keep AI agents from slipping in via accounts, API keys or tokens with excessive permissions.
Pérez Bes said manual intervention is no longer enough when it comes to security. "Human supervision remains essential, but it must be supported by detection, containment, and response mechanisms capable of operating quickly enough," he said.
FOLLOW US ON SOCIAL MEDIA
Follow ITPro on Google News and add us as a preferred source to keep tabs on all our latest news, analysis, views, and reviews.
You can also follow ITPro on LinkedIn, X, Facebook, and BlueSky.
Freelance journalist Nicole Kobie first started writing for ITPro in 2007, with bylines in New Scientist, Wired, PC Pro and many more.
Nicole the author of a book about the history of technology, The Long History of the Future.

