The exploit involved Zoom’s annotation feature, which allows users to draw on their screen while sharing it with other meeting participants. With the exploit, an attacker could join or host a meeting and run malicious code on victims’ devices, allowing them to steal data, turn on the camera or microphone, or install malware. The attack required no action from victims and showed “no visual cue indicating the compromise,” according to A Security.

“Producing a working exploit against it has always been nation-state work: elite teams, months of effort, budgets that governments regulate as weapons,” Idan Levcovich, a vulnerability researcher at A Security, writes in the blog post. “A [Security] did it in a single day, with an AI agent and models anyone can access today.” Zoom issued a fix for the vulnerability on Tuesday, which impacted the app across Windows, macOS, Linux, Android, and iOS.