Detectionmediumtest
Invoke-Obfuscation COMPRESS OBFUSCATION - PowerShell
Detects Obfuscated Powershell via COMPRESS OBFUSCATION
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Timur Zinniatullin, oscd.communityCreated Sun Oct 18Updated Tue Nov 2920e5497e-331c-4cd5-8d36-935f6e2a9a07windows
Log Source
WindowsPowerShell Script
ProductWindows← raw: windows
CategoryPowerShell Script← raw: ps_script
Definition
Requirements: Script Block Logging must be enabled
Detection Logic
Detection Logic1 selector
detection:
selection_4104:
ScriptBlockText|contains|all:
- 'new-object'
- 'text.encoding]::ascii'
ScriptBlockText|contains:
- 'system.io.compression.deflatestream'
- 'system.io.streamreader'
ScriptBlockText|endswith: 'readtoend'
condition: selection_4104False Positives
Unknown
False positive likelihood has not been assessed. Additional context may be needed during triage.
References
MITRE ATT&CK
Techniques
Sub-techniques
Rule Metadata
Rule ID
20e5497e-331c-4cd5-8d36-935f6e2a9a07
Status
test
Level
medium
Type
Detection
Created
Sun Oct 18
Modified
Tue Nov 29
Author
Path
rules/windows/powershell/powershell_script/posh_ps_invoke_obfuscation_via_compress.yml
Raw Tags
attack.defense-evasionattack.t1027attack.executionattack.t1059.001