Unusual File Deletion by Dns.exe — Sigma Rule

Rule metadata and linked tags

Author: Tim Rauch (Nextron Systems), Elastic (idea). Source status: test; severity: high. Source dates: 2022-09-27 / 2023-02-15.

{
  "category": "file_delete",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 94256741ead5b1c08b6f95d093a0320bc6d98d33e318d87f040c5932305779db

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: Unusual File Deletion by Dns.exe
id: 8f0b1fb1-9bd4-4e74-8cdf-a8de4d2adfd0
related:
    - id: 9f383dc0-fdeb-4d56-acbc-9f9f4f8f20f3 # FileChange version
      type: similar
status: test
description: Detects an unexpected file being deleted by dns.exe which my indicate activity related to remote code execution or other forms of exploitation as seen in CVE-2020-1350 (SigRed)
references:
    - https://www.elastic.co/guide/en/security/current/unusual-file-modification-by-dns-exe.html
author: Tim Rauch (Nextron Systems), Elastic (idea)
date: 2022-09-27
modified: 2023-02-15
tags:
    - attack.persistence
    - attack.initial-access
    - attack.t1133
logsource:
    category: file_delete
    product: windows
detection:
    selection:
        Image|endswith: '\dns.exe'
    filter:
        TargetFilename|endswith: '\dns.log'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.elastic.co/guide/en/security/current/unusual-file-modification-by-dns-exe.html