Windows Persistence: Outlook LoadMacroProviderOnBoot Registry Setting Modification

Alerts on enabling the Outlook LoadMacroProviderOnBoot registry setting, which can allow automatic VBA module loading at startup.

FreeReviewedSigma · High · v1
Product
windows
Category
registry_set
Author
Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2021-04-05
Updated
2026-07-30

ATT&CK techniques

Persistence → C2
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Defense Evasion

  6. Cred Access

  7. Discovery

  8. Lateral Movement

  9. Collection

  10. Exfiltration

  11. Impact

What it detects

This rule flags registry changes to the Outlook setting LoadMacroProviderOnBoot when the value indicates it is enabled (0x00000001). If set to allow macro provider loading on boot, it can give attackers a way to automatically load a configured VBA project or module without user interaction. The detection relies on Windows registry set telemetry capturing changes to the target Outlook registry path and value contents.

Related detections9 linkedT1137 — drag to rearrange
Windows: Suspicious Outlook VbaProject.OTM Macro File Created
Windows: New Outlook VBAProject OTM Macro File Created
Windows Registry: Outlook Macro Security Level Set to Enable All Macros
Suspicious Office Application Spawning Mshta With Remote HTA
AdminSDHolder Permissions Changed for Persistence (via security)
Malicious NotDoor Outlook VBA Persistence via VbaProject.OTM Deployment (via process_creation)
Malicious NotDoor Outlook Macro Auto-Execution Enablement via Registry (via registry_set)
Suspicious Persistence via Shell Script Dropped in profile.d Directory (via file_event)
Office Persistence via WLL Add-in Dropped to Word STARTUP Folder
Windows Persistence: Outlook LoadMacroProviderOnBoot Registry Setting Modification
Pivot detection · T1137 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.