Self-Propagating Prompt-Injection Worm Confirmed in Microsoft Copilot for Word After 144 Days of Coordinated Disclosure
Enklype Salt published 'Context Collapse Part 3' on July 28, documenting a document-borne worm in Microsoft Copilot for Word: hidden white-text instructions in a source document are executed by Copilot's magic pen and 'Edit with Copilot' in Work/Work IQ mode, then copied verbatim into the generated document, which becomes a new carrier when a colleague later uses it as source material. Reported March 6 and disclosed July 28 after the 90-day window was extended twice to 144 days, Microsoft shipped two mitigation attempts including a model upgrade to GPT-5.5, but the researchers state the broader vulnerability class remained reproducible with modified payloads at publication. For builders this is the concrete failure mode of agent-written artifacts inside collaboration SaaS: the propagation vector is the normal document workflow, not an exploit chain, so no perimeter control catches it.
↳ Follow the thread