SesameOp: Novel backdoor using OpenAI Assistants API for command and control

Wambua Thyaka@thyaka

•updated Nov 5, 2025•39•0•204

SesameOP Uses OpenAI Assistants API as a mechanism for command-and-control (C2) communications. Instead of relying on more traditional methods, the threat actor behind this backdoor abuses OpenAI as a C2 channel as a way to stealthily communicate and orchestrate malicious activities within the compromised environment. To do this, a component of the backdoor uses the OpenAI Assistants API as a storage or relay mechanism to fetch commands, which the malware then runs.