Techniques
Sample rules
Detect Copy of ShadowCopy with Script Block Logging
- source: splunk
- technicques:
- T1003.002
- T1003
Description
The following analytic utilizes PowerShell Script Block Logging (EventCode=4104) to identify suspicious PowerShell execution. Script Block Logging captures the command sent to PowerShell, the full command to be executed. Upon enabling, logs will output to Windows event logs. Dependent upon volume, enable on critical endpoints or all.
This analytic identifies copy or [System.IO.File]::Copy being used to capture the SAM, SYSTEM or SECURITY hives identified in script block. This will catch the most basic use cases for credentials being taken for offline cracking.
During triage, review parallel processes using an EDR product or 4688 events. It will be important to understand the timeline of events around this activity. Review the entire logged PowerShell script block.
Detection logic
`powershell` EventCode=4104 ScriptBlockText IN ("*copy*","*[System.IO.File]::Copy*") AND ScriptBlockText IN ("*System32\\config\\SAM*", "*System32\\config\\SYSTEM*","*System32\\config\\SECURITY*")
| stats count min(_time) as firstTime max(_time) as lastTime by Opcode Computer UserID EventCode ScriptBlockText
| rename Computer as dest
| rename UserID as user
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `detect_copy_of_shadowcopy_with_script_block_logging_filter`