Password Protected ZIP File Opened (Email Attachment) — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2022-05-09 / not supplied.

{
  "product": "windows",
  "service": "security"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 387d889a49e08a74061b0e6f6a09f534683f7a0f8f28ef203a3b54719f242ff0

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Password Protected ZIP File Opened (Email Attachment)
id: 571498c8-908e-40b4-910b-d2369159a3da
status: test
description: Detects the extraction of password protected ZIP archives. See the filename variable for more details on which file has been opened.
references:
    - https://twitter.com/sbousseaden/status/1523383197513379841
author: Florian Roth (Nextron Systems)
date: 2022-05-09
tags:
    - attack.initial-access
    - attack.stealth
    - attack.t1027
    - attack.t1566.001
logsource:
    product: windows
    service: security
detection:
    selection:
        EventID: 5379
        TargetName|contains|all:
            - 'Microsoft_Windows_Shell_ZipFolder:filename'
            - '\Temporary Internet Files\Content.Outlook'
    condition: selection
falsepositives:
    - Legitimate used of encrypted ZIP files
level: high

Original YAML and metadata in JSON

False positives

• Legitimate used of encrypted ZIP files

Source references

• https://twitter.com/sbousseaden/status/1523383197513379841