Detectionmediumtest

Invoke-Obfuscation COMPRESS OBFUSCATION - Security

Detects Obfuscated Powershell via COMPRESS OBFUSCATION

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Launch
Timur Zinniatullin, oscd.communityCreated Sun Oct 18Updated Tue Nov 297a922f1b-2635-4d6c-91ef-af228b198ad3windows
Log Source
Windowssecurity
ProductWindows← raw: windows
Servicesecurity← raw: security

Definition

The 'System Security Extension' audit subcategory need to be enabled to log the EID 4697

Detection Logic
Detection Logic1 selector
detection:
    selection:
        EventID: 4697
        ServiceFileName|contains|all:
            - 'new-object'
            - 'text.encoding]::ascii'
            - 'readtoend'
        ServiceFileName|contains:
            - 'system.io.compression.deflatestream'
            - 'system.io.streamreader'
    condition: selection
False Positives
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

Rule Metadata
Rule ID
7a922f1b-2635-4d6c-91ef-af228b198ad3
Status
test
Level
medium
Type
Detection
Created
Sun Oct 18
Modified
Tue Nov 29
Path
rules/windows/builtin/security/win_security_invoke_obfuscation_via_compress_services_security.yml
Raw Tags
attack.defense-evasionattack.t1027attack.executionattack.t1059.001
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