Suspicious User-Agent Strings Associated with GraphRunner
This rule detects suspicious user-agent strings associated with the GraphRunner tool. GraphRunner is a PowerShell script used for interacting with Microsoft Graph API and other Microsoft services, often for malicious purposes like token manipulation or brute-forcing client IDs. The rule specifically looks for a predefined set of user-agent strings that are hardcoded within GraphRunner's functions. Detection is focused on Azure Activity, Office 365, Azure AD, Azure AD Directory Audit, and Microsoft Graph Activity logs. The rule aggregates detections by principal IP or user ID over a 5-minute window.
YARA-L
