Not long ago, more than a hundred companies published an open letter to sound the alarm. This warning concerns an imminent scale-up of AI-powered cyberattacks. According to the signatories, the world has a limited window to reinforce its cyber defenses before this type of technology makes digital offensives massively harder to counter.
An unprecedented coalition led by OpenAI
In November 2025, we discussed a cyberattack involving the company Anthropic. It asserted that it had thwarted a large-scale cyberattack carried out by pirates likely to be Chinese. According to Anthropic, the criminals mobilized the Claude Code agent to automate between 80% and 90% of the hacking campaign. For Anthropic, this would be the first cyberattack of its kind, at least the first one documented.
Since that attack, a series of similar incidents has occurred over 2026. For instance, the emergence of autonomous mutating malware, evasion and autonomous hacking of OpenAI, or Anthropic’s evaluation bug. In response to this wave of incidents, a unprecedented coalition led by OpenAI, bringing together 128 giants of technology, cybersecurity, and finance, published an open letter on August 27, 2026.
A narrow window to bolster cyber defenses
According to the signatories, AI-powered cyberattacks are about to scale up. However, the world has time to reinforce its cyber defenses before these technologies make digital offensives massively faster, more automated, and more sophisticated. Yet there is talk of a limited, urgent window, despite the existence of means to guard against it.
“The current advances in AI already give defenders new means to fix weaknesses that have built up over years. If we act with resolve, we can seize the defenders’ window of opportunity to make our digital world much safer.”, reads the letter.
Among the 128 companies that signed the famous letter we naturally find OpenAI but also Microsoft, Google, IBM, Anthropic, Mastercard, Visa, PayPal, Oracle, Adobe, General Motors, AMD, Nokia, Ericsson, and Firefox. The coalition thus brings together major players in the global digital sector, more precisely in the fields of AI, Internet and cloud, but also in banking, telecommunications, and the automotive industry.
A multi-pronged action plan
The signatories are notably concerned about the vulnerability of essential services that people rely on daily. The fears center on hospitals and health systems, water treatment facilities and distribution networks, but also on the broader infrastructure that keeps the Internet running.
To meet this looming threat, the coalition proposes a plan of action built around several pillars. First, a commitment to use the power of AI to automatically fix security flaws faster than the hackers can exploit them. Then comes the need to ensure responsible access to models, as well as the allocation of specific technical and financial resources to protect fragile infrastructures.
The signatories also called on governments to co-finance the protection of organizations—particularly some public hospitals—that would lack budget and skilled staff to confront the threat. A final point concerns private companies, invited to share their data immediately in case of detected cyber threats.
