Suspicious Hidden Local Account via SpecialAccounts UserList Registry Value (via registry_set)
- Product
- windows
- Category
- registry_set
- Author
- HuntRule
- Published
- 2026-06-15
- Updated
- 2026-08-28
ATT&CK techniques
Defense EvasionRecon
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 a UserList value written under Winlogon SpecialAccounts to hide a local account from the Windows sign-in screen, a defense-evasion behavior MuddyWater uses after creating a covert admin account. Adversaries leverage this registry hiding so their persistent account stays invisible to interactive users.
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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Also included
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