CuraSec

tag: C2-Abuse · 1 items

2026-07-21 · The Hacker News · source ↗ #microsoft-365#c2-abuse#espionage
  • Engineer — Plan: Novel Graph API abuse using calendar write access highlights over-permissioned OAuth app risk. Audit which apps hold Microsoft Graph calendar read/write scopes and revoke unnecessary permissions this quarter.
  • SOC/IR — Act: The year-2050 calendar event timestamp is a highly specific, huntable indicator — sweep M365 audit logs for calendar events created with 2050 dates and flag Graph API calls that write calendar entries with large attachments.
  • Leader — Learn: Espionage actors using legitimate Microsoft 365 infrastructure for C2 blurs the line between sanctioned SaaS activity and intrusion; useful context for understanding the M365-as-attack-surface risk but no immediate leadership action required.