APT28 NotDoor Outlook Macro Security Bypass (via registry_set)
- Product
- windows
- Category
- registry_set
- Author
- HuntRule
- Published
- 2026-08-08
- Updated
- 2026-08-28
ATT&CK techniques
PersistenceRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects Outlook security policy changes that lower the macro security Level to one and enable LoadMacroProviderOnBoot, the registry tampering APT28 performs to auto-load its NotDoor VBA backdoor at Outlook startup. Adversaries leverage these values to run malicious macros without prompts, making detection of either change important for catching mail-client persistence.
Reporting behind it
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
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