Attacker Hijacks AI Coding Assistant Session, Spreads Shai-Hulud Across About 100 Repositories

Attacker Hijacks AI Coding Assistant Session, Spreads Shai-Hulud Across About 100 Repositories Swati KhandelwalSep 16, 2026Artificial Intelligence / Software Security Mandiant says an attacker hijacked an active AI coding-assistant session at an unnamed software-as-a-service provider and later spread Shai-Hulud across about 100 internal code repositories. Before the repository spread, the assistant recommended software that the attacker had poisoned, and the recommendation was accepted. The worm stole repository secrets and source code for the company's products. The case appears in Mandiant's September 2026 report. The public case study does not say when the intrusion happened or how the attacker took over the active coding-assistant session. How the Attack Unfolded After the recommendation was accepted, the attacker used the developer's active session…