PowerShell Suspicious Payload Encoded and Compressededit

Identifies the use of .NET functionality for decompression and base64 decoding combined in PowerShell scripts, which malware and security tools heavily use to deobfuscate payloads and load them directly in memory to bypass defenses.

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: None


  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Defense Evasion

Version: 2

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule queryedit

event.category:process and
  powershell.file.script_block_text : (
    (System.IO.Compression.DeflateStream or System.IO.Compression.GzipStream or IO.Compression.DeflateStream or IO.Compression.GzipStream) and