From AI-enabled killer drones to AI-made pathogens: MI5 chief warns new era of cyber warfare

MI5 chief Ken McCallum on Tuesday said terrorists have been found utilizing AI to "supercharge" attacks, bringing in a new era of cyber warfare that could lead to novel chemicals, pathogens, and biological weapons we are not prepared for.

The head of UK intelligence made the remarks while delivering his annual national security threat update in London, also announcing the launch of a new AI Threat Assessment Centre (AITAC).

Working closely with the UK’s AI Security Institute (AISI), National Cyber Security Centre (NCSC), and the National Crime Agency (NCA), the new AITAC will assess national security threats stemming from AI misuse.

The Director General of the UK’s domestic security service focused heavily on risks to critical infrastructure, noting that many current systems – including financial systems, energy grids, supply chains, and manufacturing bases – were “designed during simpler times.”

“A hack of your banking app could lock you out of your accounts. A drone on an airport runway could leave you stranded far from home. A cyber-attack on your local hospital could delay your treatment,” he said, all real-world scenarios the UK has faced in the past few years alone.

AI could create threats the world has never faced

McCallum describes the “new era of security” as hybrid warfare – one where adversaries are not just targeting infrastructure but also using online propaganda to manipulate the way we feel.

QUOTE: Today AI is already supercharging the cybersecurity contest between attackers and defenders.

said MI5 Director General Sir Ken McCallum.

But perhaps most concerning is his warning that AI is permeating all aspects of warfare, and although right now most would-be terror proxies are “comparatively low sophistication actors,” AI could easily grant them access to more dangerous capabilities and weapons.

Speaking to reporters, he rattled off a list of deadly possibilities that terrorists “would dearly love” to get their hands on, including chemical, biological, or radiological weapons, and even the “possibility that AI could generate novel pathogens not previously seen.”

Human history has given us no experience of facing an actor which is smarter than we are. Is capable of out-thinking us.

This is genuinely novel. And deserves the serious attention it is getting,

said MI5 Director General Sir Ken McCallum.

“Human history has given us no experience of facing an actor which is smarter than we are, is capable of out-thinking us.” In today's MI5 annual threat update, MI5’s Director General Sir Ken McCallum warns of the risk posed by AI itself: https://t.co/R2RFfwwu97

undefined ControlAI (@ControlAI) October 13, 2026

McCallum stressed the importance of the Five Eyes alliance to analyze emerging dangers and build innovative new structures to meet those new threats, as was accomplished after the September 11th attacks.

The intelligence chief noted that MI5 has already witnessed terrorists exploiting AI to improve their reconnaissance and attack methodologies, including the use of AI-enabled drones.

McCallum ended his speech noting state risks from Russia, China, and Iran, specifically mentioning the suspected Iran-linked terror plot to bomb a US military base in the UK, for which 20 suspects were arrested on September 27th.