Leading developers of the most powerful artificial intelligence tools are warning that their technology may soon be used to carry out sophisticated cyberattacks against companies and institutions, ranging from hospitals to technology firms.

In an open letter published Thursday, the leaders of OpenAI, Anthropic, Google, Microsoft and dozens of other signatories said there is a “limited window” to strengthen cyber defenses and protect against potentially devastating AI-enabled cyberattacks. That window may last only months, it added.

The signatories also include security companies like CrowdStrike and banks including Citi and Capital One.

The same AI advances that could increase risks to public services and technology infrastructure can also help organizations identify and “fix weaknesses” that leave them vulnerable, the letter said.

“If we act decisively, we can use the defenders’ window to make our digital world much more secure,” the letter said.

A recent CrowdStrike report on cybersecurity found that AI-enabled attacks increased by 89% in 2025 compared to 2024.

How to defend against attacks

The companies said that the status quo for cybersecurity “won’t be enough.”

“Longstanding bugs, excessive permissions, misconfigurations, insecure and unpatched software, weak authentication and technical debt in legacy systems have left systems exposed,” the letter said. 

Security teams need to be beefed up and invested in, while defenders against AI cyberattacks need to be equipped with the most sophisticated AI-enabled tech, it said. 

The letter also called on companies and experts to share their expertise. 

“Share threat intelligence and tested playbooks, and measure progress by how many organizations are protected, how quickly attacks are contained, and whether fixes work,” it added.

Call to action

Every organization needs to prioritize cybersecurity, according to the letter. That might include replacing or upgrading older tech systems that are vulnerable to attack. 

Specialized cybersecurity firms have an obligation to test defenses against evolving cyber capabilities continually. Governments also have a key role to play in containing cyber threats through coordinated actions and by funding cyber defense strategies at the local, national, and international levels, it added.

Lastly, the letter said it is incumbent upon frontrunner AI companies — including those that signed the document — to fund training, provide “responsible” access to their models, and adequately secure them.