Suspicious Script Object Execution

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-*

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: Sysmon

Version: 108

Rule authors:

Elastic

Rule license: Elastic License v2

Rule query

edit

any where host.os.type == "windows" and
 (event.category == "library" 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&CK^TM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: System Binary Proxy Execution
- ID: T1218
- Reference URL: https://attack.mitre.org/techniques/T1218/
Sub-technique:
- Name: Regsvr32
- ID: T1218.010
- Reference URL: https://attack.mitre.org/techniques/T1218/010/

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