Detect Conditional Access Policies in CrowdStrike LogScale
Adversaries may disable or modify Conditional Access Policies (CAP) to enable persistent access to compromised accounts. Conditional Access applies additional verification based on IP, device enrollment, MFA, and risk-based signals. Attackers modify CAPs by adding trusted IP ranges (Scattered Spider added attacker-controlled IPs), removing MFA requirements, adding user exclusions, or disabling policies. Storm-0501 circumvented CAPs using hybrid-joined servers. In AWS/GCP, IAM condition attributes can be weakened by removing IP or time-of-day restrictions.
MITRE ATT&CK
- Technique
- T1556 Modify Authentication Process
- Sub-technique
- T1556.009 Conditional Access Policies
- Canonical reference
- https://attack.mitre.org/techniques/T1556/009/
LogScale Detection Query
#repo = azure_audit
| (loggedByService = "Conditional Access" OR category = "Policy")
| operationName in ["Add conditional access policy", "Update conditional access policy",
"Delete conditional access policy", "Add named location",
"Update named location", "Delete named location"]
| result = "success"
| case {
operationName = "Delete conditional access policy" |
Risk := "CRITICAL" ;
operationName = "Update conditional access policy" AND newValue = /(?i)disabled/ |
Risk := "CRITICAL" ;
operationName in ["Add named location", "Update named location"] AND
newValue = /(?i)trusted/ | Risk := "HIGH" ;
propertyName = /(?i)grantControls/ | Risk := "HIGH" ;
* | Risk := "MEDIUM"
}
| select([_time, initiatedByUserUPN, operationName, targetResourceDisplayName,
propertyName, oldValue, newValue, Risk])
| sort(Risk, order=desc)CrowdStrike LogScale (Humio) query detecting Azure AD Conditional Access Policy and Named Location modifications from Azure audit logs ingested into the azure_audit repository. Uses case-based risk tiering with regex matching: policy deletion and disabling updates are CRITICAL, trusted location additions and grantControls changes are HIGH, new policy creation is MEDIUM. Scoped to successful operations only to reduce noise.
Data Sources
Required Tables
False Positives & Tuning
- IT operations teams updating named location IP ranges after office network changes, SD-WAN migrations, or new VPN concentrator deployments
- Zero Trust maturity programs temporarily disabling legacy CAPs before migrating users to replacement policies with stronger controls
- Microsoft Graph API-driven automation (e.g., Entra ID lifecycle workflows) that adjusts CAP exclusion group membership as part of joiner/mover/leaver processes
Other platforms for T1556.009
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Disable a Non-Critical Conditional Access Policy
Expected signal: Azure AD Audit Log: OperationName 'Update conditional access policy', ModifiedProperties showing State changed from 'enabled' to 'disabled'. Actor logged as the authenticated Microsoft Graph session user.
- Test 2Add a Trusted Named Location (Simulating Scattered Spider TTP)
Expected signal: Azure AD Audit Log: OperationName 'Add named location', TargetResources showing the new location name and IP range. IsTrusted=true visible in audit details.
- Test 3Enumerate Existing Conditional Access Policies
Expected signal: Azure AD Audit Log: Read operation on conditional access policies. Microsoft Graph API call logged. PowerShell ScriptBlock Log Event ID 4104 with the Get-MgIdentityConditionalAccessPolicy command.
References (5)
- https://attack.mitre.org/techniques/T1556/009/
- https://learn.microsoft.com/en-us/entra/identity/conditional-access/overview
- https://docs.microsoft.com/en-us/azure/active-directory/governance/conditional-access-exclusion
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1556.009/T1556.009.md
- https://www.microsoft.com/en-us/security/blog/2023/10/25/octo-tempest-crosses-boundaries-to-facilitate-extortion-encryption-and-destruction/
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