SesameOp Backdoor

Microsoft details novel backdoor abusing OpenAI API

Microsoft Discloses “SesameOp” Backdoor Abusing OpenAI API for Stealthy Command and Control

Nov 4, 2025

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by

Lara De Jong

in Threat Actors

Microsoft has identified a novel backdoor, designated “SesameOp,” that employs OpenAI’s Assistants API for its command-and-control (C2) infrastructure. This technique allows threat actors to stealthily manage compromised systems and orchestrate malicious activities by using the API as a communication relay.