Date: 08/22/2024
Severity: Medium
Summary
Detects changes to the "StrongAuthenticationRequirement" value when it is set to "0" or "Disabled". Threat actors have been observed disabling multi-factor authentication to maintain or gain access to accounts, a tactic also seen in SIM swap attacks.
Indicators of Compromise (IOC) List
LoggedByService | 'Core Directory' |
Category | 'UserManagement' |
OperationName | 'Update user' |
TargetResources.ModifiedProperties.DisplayName | 'StrongAuthenticationRequirement' |
TargetResources.ModifiedProperties.NewValue | "State\":0" |
Gurucul Threat Detection and Incident Response (TDIR) Queries for Detection
Detection Query 1 | ((resourcename = "Azure AD Directory Audit" AND loggedbyservice = "Core Directory" ) AND operationtype = "Update user" ) AND category = "UserManagement" AND rawmessages In ("'StrongAuthenticationRequirement'" , "State\":0" ) |
Detection Query 2 | ((Technologygroup = "EDR" AND loggedbyservice = "Core Directory" ) AND operationtype = "Update user" ) AND category = "UserManagement" AND rawmessages In ("'StrongAuthenticationRequirement'" , "State\":0" ) |
Reference:
https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/azure/audit_logs/azure_user_account_mfa_disable.yml
https://www.sans.org/blog/defending-against-scattered-spider-and-the-com-with-cybercrime-intelligence/