According to Axios, OpenAI, Anthropic, Amazon Web Services, Microsoft and more than 100 other companies said Thursday that organizations have only months to prepare for AI-enabled cyberattacks. In an open letter, the group said hospitals, water treatment plants and other critical infrastructure face a wave of hacking threats as AI makes advanced cyber capabilities cheaper and more accessible to attackers. The signatories called for collective action, urging companies and governments to strengthen cyber defenses, raise security standards, share threat intelligence and fund cyber defense. The letter also said frontier AI companies should give defenders access to their most capable response models during major cyber incidents, along with funding, training and hands-on support. Axios said the warning comes amid a rise in attacks on critical infrastructure, including one targeting U.S. water systems with an apparent AI-generated exploitation script, but the signatories did not announce commitments, deadlines or specific investments.