T1531 Account Access Removal — Detection Rules

Source-backed rule directory

• AWS SAML Provider Deletion Activity · experimental · medium · {"product":"aws","service":"cloudtrail"}
• AWS ElastiCache Security Group Modified or Deleted · test · low · {"product":"aws","service":"cloudtrail"}
• Azure Kubernetes Service Account Modified or Deleted · test · medium · {"product":"azure","service":"activitylogs"}
• Google Cloud Service Account Disabled or Deleted · test · medium · {"product":"gcp","service":"gcp.audit"}
• Okta User Account Locked Out · test · medium · {"product":"okta","service":"okta"}
• Group Has Been Deleted Via Groupdel · test · medium · {"product":"linux","category":"process_creation"}
• User Has Been Deleted Via Userdel · test · medium · {"product":"linux","category":"process_creation"}
• User Logoff Event · test · informational · {"service":"security","product":"windows"}
• Remove Account From Domain Admin Group · test · medium · {"product":"windows","category":"ps_script","definition":"Requirements: Script Block Logging must be enabled"}

Atlas deterministic concepts

T1531 Account Access Removal

MATCH(account_disabled_or_deleted OR credential_reset OR role_removed) AND actor NOT_IN approved_identity_admins -> ALERT

• Identity Provider Audit Logs
• Directory-Service Audit Logs
• Cloud Identity and Access Management Logs
• Atlas source section

Anomaly models

No exact Atlas model in this snapshot.

ATT&CK analytic guidance

DET0120 Account Access Removal via Multi-Platform Audit Correlation

AN0334 Analytic 0334

Correlated user account modification (reset, disable, deletion) events with anomalous process lineage (e.g., PowerShell or net.exe from an interactive session), especially outside of IT admin change windows or by non-admin users.

AN0335 Analytic 0335

Password changes or account deletions via 'passwd', 'userdel', or 'chage' preceded by interactive shell or remote command execution from non-privileged accounts.

AN0336 Analytic 0336

Execution of dscl or sysadminctl commands to disable, delete, or modify users combined with anomalous process ancestry or terminal session launch.

AN0337 Analytic 0337

Invocation of esxcli 'system account remove' from vCLI, SSH, or vSphere API with anomalous user access or outside maintenance windows.

AN0338 Analytic 0338

O365 UnifiedAuditLog entries for Remove-Mailbox or Set-Mailbox with account disable or delete actions correlated with suspicious login locations or MFA bypass.

AN0339 Analytic 0339

Deletion or disablement of user accounts in platforms like Okta, Salesforce, or Zoom with anomalies in admin session attributes or mass actions within short duration.