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Elastic Docs ›Elastic Security Solution [7.11] ›Detections and Alerts ›Prebuilt rule reference

Encrypting Files with WinRar or 7z

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Encrypting Files with WinRar or 7z

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Identifies use of WinRar or 7z to create an encrypted files. Adversaries will often compress and encrypt data in preparation for exfiltration.

Rule type: eql

Rule indices:

  • logs-endpoint.events.*
  • winlogbeat-*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-6m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Exfiltration

Version: 2 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 7.11.2

Rule authors: Elastic

Rule license: Elastic License

Rule query

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process where event.type in ("start", "process_started") and
((process.name:"rar.exe" or process.code_signature.subject_name ==
"win.rar GmbH" or process.pe.original_file_name == "Command line
RAR") and process.args == "a" and process.args : ("-hp*", "-p*",
"-dw", "-tb", "-ta", "/hp*", "/p*", "/dw", "/tb", "/ta")) or
(process.pe.original_file_name in ("7z.exe", "7za.exe") and
process.args == "a" and process.args : ("-p*", "-sdel")) /*
uncomment if noisy for backup software related FPs */ /* not
process.parent.executable : ("C:\\Program Files\\*.exe", "C:\\Program
Files (x86)\\*.exe") */

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 2 (7.11.2 release)
  • Formatting only
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