IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
PowerShell PSReflect Script
editPowerShell PSReflect Script
editDetects the use of PSReflect in PowerShell scripts. Attackers leverage PSReflect as a library that enables PowerShell to access win32 API functions.
Rule type: query
Rule indices:
- winlogbeat-*
- logs-windows.*
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:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Execution
Version: 2
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
edit## Triage and analysis ### Investigating PowerShell PSReflect Script PowerShell is one of the main tools in the belt of system administrators for automation, report routines, and other tasks. PSReflect is a library that enables PowerShell to access win32 API functions in an uncomplicated way. It also helps to create enums and structs easily—all without touching the disk. Although this is an interesting project for every developer and admin out there, it is mainly used in the red team and malware tooling for its capabilities. Detecting the core implementation of PSReflect means detecting most of the tooling that uses Windows API through PowerShell, enabling the defender to discover tools being dropped in the environment. #### Possible investigation steps: - Check for additional PowerShell logs that indicate that the script/command was run. - Gather the script content that may be split into multiple script blocks, and identify its capabilities. - If the action is suspicious for the user, check for any other activities done by the user in the last 48 hours. - Look for additional alerts involving the host and the user. ### False Positive Analysis - Verify whether the script content is malicious/harmful. ### Related Rules - PowerShell Suspicious Discovery Related Windows API Functions - 61ac3638-40a3-44b2-855a-985636ca985e - PowerShell Keylogging Script - bd2c86a0-8b61-4457-ab38-96943984e889 - PowerShell Suspicious Script with Audio Capture Capabilities - 2f2f4939-0b34-40c2-a0a3-844eb7889f43 - Potential Process Injection via PowerShell - 2e29e96a-b67c-455a-afe4-de6183431d0d - PowerShell Reflection Assembly Load - e26f042e-c590-4e82-8e05-41e81bd822ad - PowerShell Suspicious Payload Encoded and Compressed - 81fe9dc6-a2d7-4192-a2d8-eed98afc766a - PowerShell Suspicious Script with Screenshot Capabilities - 959a7353-1129-4aa7-9084-30746b256a70 ### Response and Remediation - Immediate response should be taken to validate activity, investigate, and potentially isolate activity to prevent further post-compromise behavior. ## Config The 'PowerShell Script Block Logging' logging policy is required be configured (Enable). Steps to implement the logging policy with with Advanced Audit Configuration: ``` Computer Configuration > Administrative Templates > Windows PowerShell > Turn on PowerShell Script Block Logging (Enable) ``` Steps to implement the logging policy via registry: ``` reg add "hklm\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ScriptBlockLogging" /v EnableScriptBlockLogging /t REG_DWORD /d 1 ```
Rule query
editevent.category:process and powershell.file.script_block_text:( New-InMemoryModule or Add-Win32Type or psenum or DefineDynamicAssembly or DefineDynamicModule or Reflection.TypeAttributes or Reflection.Emit.OpCodes or Reflection.Emit.CustomAttributeBuilder or Runtime.InteropServices.DllImportAttribute )
Framework: MITRE ATT&CKTM
-
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/
-
Sub-technique:
- Name: PowerShell
- ID: T1059.001
- Reference URL: https://attack.mitre.org/techniques/T1059/001/
-
Technique:
- Name: Native API
- ID: T1106
- Reference URL: https://attack.mitre.org/techniques/T1106/