This documentation contains work-in-progress information for future Elastic Stack and Cloud releases. Use the version selector to view supported release docs. It also contains some Elastic Cloud serverless information. Check out our serverless docs for more details.

« Sudoers File Modification Suspicious .NET Reflection via PowerShell »

› › ›

Suspicious .NET Code Compilation

edit

Suspicious .NET Code Compilation

edit

Identifies suspicious .NET code execution. connections.

Rule type: eql

Rule indices:

winlogbeat-*
logs-endpoint.events.*
logs-windows.*
endgame-*

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
Elastic Endgame

Version: 102 (version history)

Added (Elastic Stack release): 7.10.0

Last modified (Elastic Stack release): 8.6.0

Rule authors: Elastic

Rule license: Elastic License v2

Investigation guide

edit

Rule query

edit

process where event.type == "start" and process.name : ("csc.exe",
"vbc.exe") and process.parent.name : ("wscript.exe", "mshta.exe",
"cscript.exe", "wmic.exe", "svchost.exe", "rundll32.exe", "cmstp.exe",
"regsvr32.exe")

Threat mapping

edit

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: Obfuscated Files or Information
- ID: T1027
- Reference URL: https://attack.mitre.org/techniques/T1027/

Rule version history

edit

Version 102 (8.6.0 release)

Formatting only

Version 101 (8.5.0 release)

Updated query, changed from:

process where event.type in ("start", "process_started") and
process.name : ("csc.exe", "vbc.exe") and process.parent.name :
("wscript.exe", "mshta.exe", "cscript.exe", "wmic.exe", "svchost.exe",
"rundll32.exe", "cmstp.exe", "regsvr32.exe")

Version 8 (8.4.0 release)

Formatting only

Version 6 (8.2.0 release)

Formatting only

Version 5 (7.16.0 release)

Formatting only

Version 4 (7.12.0 release)

Formatting only

Version 3 (7.11.2 release)

Formatting only

Version 2 (7.11.0 release)

Updated query, changed from:

event.category:process and event.type:(start or process_started) and
process.name:(csc.exe or vbc.exe) and process.parent.name:(wscript.exe
or mshta.exe or wscript.exe or wmic.exe or svchost.exe or rundll32.exe
or cmstp.exe or regsvr32.exe)

« Sudoers File Modification Suspicious .NET Reflection via PowerShell »