IMPORTANT: No additional bug fixes or documentation updates will be released for this version. For the latest information, see the current release documentation.

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Suspicious .NET Reflection via PowerShell

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Suspicious .NET Reflection via PowerShell

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This rule detects the use of Reflection.Assembly to load PEs and DLLs in memory in Powershell Scripts. Attackers use this method to load executables and DLLs without writing to the disk, bypassing security solutions.

Rule type: query

Rule indices:

winlogbeat-*
logs-windows.*

Severity: high

Risk score: 73

Runs every: 5 minutes

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

Maximum alerts per execution: 100

References:

https://docs.microsoft.com/en-us/dotnet/api/system.reflection.assembly.load

Tags:

Elastic
Host
Windows
Threat Detection
Defense Evasion

Version: 1

Added (Elastic Stack release): 8.0.0

Rule authors: Elastic

Rule license: Elastic License v2

Rule query

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event.category:process and powershell.file.script_block_text : (
"[System.Reflection.Assembly]::Load" or
"[Reflection.Assembly]::Load" )

Threat mapping

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Framework: MITRE ATT&CK^TM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: Process Injection
- ID: T1055
- Reference URL: https://attack.mitre.org/techniques/T1055/
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
Technique:
- Name: Command and Scripting Interpreter
- ID: T1059
- Reference URL: https://attack.mitre.org/techniques/T1059/

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