Powershell script: MemoryStream usage detected (in-memory execution)

Description

Powershell script: MemoryStream usage detected (in-memory execution)

Query · wazuh

View raw source upstream ↗ Wazuh XML 
field win.eventdata.scriptBlockText="(?i)IO\.MemoryStream"

No license declared

socfortress/Wazuh-Rules publishes no license, and without an express grant the default is all rights reserved. The query above is synthesized from the rule rather than copied out of it, so you can see what the rule matches on; the rule as written stays upstream.

Read the full rule at Windows Powershell/100535-win_powershell_rules.xml ↗. Why this rule is treated this way.

Fires when

Wazuh evaluates a chain top-down. Every rule above this one must match on the same event before this rule is tested at all.

  1. 60000 Group of windows rules. anchor level 0
    decoded_as=windows_eventchannel AND field win.system.providerName="\.+"
  2. 91801 Group of Windows rules for the Powershell/Operational channel. anchor level 0
    field win.system.channel="^Microsoft-Windows-PowerShell/Operational$"
  3. 91802 Group of Windows rules for the Powershell/Operational channel. anchor level 0
    field win.eventdata.ScriptBlockId=".+"
  4. 101331 Powershell script: MemoryStream usage detected (in-memory execution) refinement level 10 this rule
    field win.eventdata.scriptBlockText="(?i)IO\.MemoryStream"

Rule dependencies

Depends on

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