KQL Search

This query is designed to detect suspicious usage of the QueueUserAPC function, which can be exploited for malicious purposes such as process injection. Here's a simplified summary:

1. Purpose: To identify potentially malicious use of the QueueUserAPC function, which can be used to execute code in the context of another process, a technique known as Asynchronous Procedure Call (APC) Injection.

2. Detection Criteria:

   • The query looks at DeviceEvents where the ActionType is "QueueUserApcRemoteApiCall".
   • It excludes events where the initiating process command line is "svchost.exe -k netsvcs -p -s ShellHWDetection".
   • It also excludes events where the initiating process is the "Microsoft Edge Installer".
   • Additionally, it excludes events where the process command line is "svchost.exe -k netsvcs -p -s Winmgmt".

3. Tags: The query is associated with process injection, APC injection, remote API calls, and is linked to the MITRE ATT&CK technique T1055.004.

4. Query:

   DeviceEvents
   | where ActionType == "QueueUserApcRemoteApiCall"
   | where InitiatingProcessCommandLine != "svchost.exe -k netsvcs -p -s ShellHWDetection"
   | where InitiatingProcessVersionInfoProductName != "Microsoft Edge Installer"
   | where ProcessCommandLine != "svchost.exe -k netsvcs -p -s Winmgmt"
   

In essence, this query helps in identifying unusual and potentially harmful uses of the QueueUserAPC function by filtering out known legitimate uses, thereby providing an early warning for possible malicious activities.