Windows Security Event 5379: Password-Protected ZIP Opened

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1027Obfuscated Files or Information
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies when Windows reports opening an encrypted, password-protected ZIP archive via Shell ZIP folder activity. Attackers may use password-protected archives to delay analysis and hinder casual inspection, especially during delivery or staging. It relies on Windows Security log EventID 5379 and matching the TargetName field content for the ZIP folder filename indicator, with an exclusion for temporary Outlook content.

Reporting behind it

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Windows Security Event 5379: Password-Protected ZIP Opened

Pivot detection · T1027 · 9 related

Changelog

v2

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

windows-security-password-protected-zip-opened-eventid-5379-00ba9da1

title: "Windows Security Event 5379: Password-Protected ZIP Opened"
id: 462e175e-b16a-44e9-bc41-6e379416fc23
status: test
description: This rule identifies when Windows reports opening an encrypted, password-protected ZIP archive via Shell ZIP folder activity. Attackers may use password-protected archives to delay analysis and hinder casual inspection, especially during delivery or staging. It relies on Windows Security log EventID 5379 and matching the TargetName field content for the ZIP folder filename indicator, with an exclusion for temporary Outlook content.
references:
  - https://twitter.com/sbousseaden/status/1523383197513379841
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_susp_opened_encrypted_zip.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2022-05-09
tags:
  - attack.stealth
  - attack.t1027
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 5379
    TargetName|contains: Microsoft_Windows_Shell_ZipFolder:filename
  filter:
    TargetName|contains: \Temporary Internet Files\Content.Outlook
  condition: selection and not filter
falsepositives:
  - Legitimate used of encrypted ZIP files
level: medium
license: DRL-1.1
related:
  - id: 00ba9da1-b510-4f6b-b258-8d338836180f
    type: derived

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