Suspicious Script Object Execution

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Identifies scrobj.dll loaded into unusual Microsoft processes. This usually means a malicious scriptlet is being executed in the target process.

Rule type: eql

Rule indices:

  • logs-endpoint.events.library-*
  • logs-windows.sysmon_operational-*
  • winlogbeat-*
  • endgame-*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Defense Evasion
  • Data Source: Elastic Defend
  • Data Source: Elastic Endgame
  • Data Source: Sysmon

Version: 109

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

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any where host.os.type == "windows" and
 (event.category : ("library", "driver") or (event.category == "process" and event.action : "Image loaded*")) and
 (?dll.name : "scrobj.dll" or ?file.name : "scrobj.dll") and
 process.executable : ("?:\\Windows\\System32\\*.exe", "?:\\Windows\\SysWOW64\\*.exe") and
 not process.executable : (
       "?:\\Windows\\System32\\cscript.exe",
       "?:\\Windows\\SysWOW64\\cscript.exe",
       "?:\\Windows\\system32\\msiexec.exe",
       "?:\\Windows\\SysWOW64\\msiexec.exe",
       "?:\\Windows\\System32\\smartscreen.exe",
       "?:\\Windows\\system32\\taskhostw.exe",
       "?:\\windows\\system32\\inetsrv\\w3wp.exe",
       "?:\\windows\\SysWOW64\\inetsrv\\w3wp.exe",
       "?:\\Windows\\system32\\wscript.exe",
       "?:\\Windows\\SysWOW64\\wscript.exe",
       "?:\\Windows\\System32\\mshta.exe",
       "?:\\Windows\\system32\\mobsync.exe",
       "?:\\Windows\\SysWOW64\\mobsync.exe",
       "?:\\Windows\\System32\\cmd.exe",
       "?:\\Windows\\SysWOW64\\cmd.exe",
       "?:\\Windows\\System32\\OpenWith.exe",
       "?:\\Windows\\System32\\wbem\\WMIADAP.exe",
       "?:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe")

Framework: MITRE ATT&CKTM