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Suspicious Script Object Execution
editSuspicious Script Object Execution
editIdentifies 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.*
Severity: medium
Risk score: 47
Runs every: 5 minutes
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Defense Evasion
Version: 4 (version history)
Added (Elastic Stack release): 7.10.0
Last modified (Elastic Stack release): 7.13.0
Rule authors: Elastic
Rule license: Elastic License v2
Rule query
editsequence by process.entity_id with maxspan=2m [process where event.type == "start" and (process.code_signature.subject_name in ("Microsoft Corporation", "Microsoft Windows") and process.code_signature.trusted == true) and not process.executable : ( "?:\\Windows\\System32\\cscript.exe", "?:\\Windows\\SysWOW64\\cscript.exe", "?:\\Program Files (x86)\\Internet Explorer\\iexplore.exe", "?:\\Program Files\\Internet Explorer\\iexplore.exe", "?:\\Windows\\SystemAp ps\\Microsoft.MicrosoftEdge_*\\MicrosoftEdge.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\\mobsync.exe", "?:\\Windows\\SysWOW64\\mobsync.exe", "?:\\Windows\\System32\\cmd.exe", "?:\\Windows\\SysWOW64\\cmd.exe")] [library where event.type == "start" and dll.name : "scrobj.dll"]
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Signed Binary Proxy Execution
- ID: T1218
- Reference URL: https://attack.mitre.org/techniques/T1218/
Rule version history
edit- Version 4 (7.13.0 release)
-
- Rule name changed from: Windows Suspicious Script Object Execution
-
Updated query, changed from:
/* add winlogbeat-* when process.code_signature.* fields are populated */ sequence by process.entity_id with maxspan = 2m [process where event.type in ("start", "process_started") and /* uncomment once in winlogbeat */ /* process.code_signature.subject_name : "Microsoft Corporation" and process.code_signature.trusted : true and */ not process.name : ( "cscript.exe", "iexplore.exe", "MicrosoftEdge.exe", "msiexec.exe", "smartscreen.exe", "taskhostw.exe", "w3wp.exe", "wscript.exe")] [library where event.type == "start" and dll.name : "scrobj.dll"]
- Version 3 (7.12.0 release)
-
-
Updated query, changed from:
/* add winlogbeat-* when process.code_signature.* fields are populated */ sequence by process.entity_id with maxspan=2m [process where event.type in ("start", "process_started") and /* uncomment once in winlogbeat */ /* process.code_signature.subject_name == "Microsoft Corporation" and process.code_signature.trusted == true and */ not (process.name : "cscript.exe" or process.name : "iexplore.exe" or process.name : "MicrosoftEdge.exe" or process.name : "msiexec.exe" or process.name : "smartscreen.exe" or process.name : "taskhostw.exe" or process.name : "w3wp.exe" or process.name : "wscript.exe")] [library where event.type == "start" and file.name : "scrobj.dll"]
-
- Version 2 (7.11.0 release)
-
- Formatting only