Azure Managed Identity Token Theft and External Replay
This rule detects the use of Azure Managed Identity tokens originating from non-Azure IP spaces. This scenario is indicative of token theft, likely via the Instance Metadata Service (IMDS) endpoint (169.254.169.254), followed by an external replay of the stolen token from an attacker's infrastructure. Legitimate Managed Identity calls are expected to originate from Azure infrastructure IPs. The rule filters out legitimate Microsoft/Azure ASNs and RFC1918 private IP ranges to reduce false positives. It also categorizes the potential attack stage based on the operation name, including Key Vault access, Storage access, VM Code Execution, Privilege Escalation, and Directory Enumeration.
Cortex XDR
