Sigma rule: Unusual File Modification by dns.exe

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-d781bade7df7, updated 2022-09-27T00:00:00.000Z.

Rule

Title
Unusual File Modification by dns.exe
Status
test
Level
high
Author
Tim Rauch (Nextron Systems), Elastic (idea)
Date
2022-09-27
File
rules/windows/file/file_change/file_change_win_unusual_modification_by_dns_exe.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects an unexpected file being modified by dns.exe which my indicate activity related to remote code execution or other forms of exploitation as seen in CVE-2020-1350 (SigRed)

Log source

product
windows
category
file_change

Detection

selection:
    Image|endswith: '\dns.exe'
filter:
    TargetFilename|endswith: '\dns.log'
condition: selection and not filter

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.persistence
  • attack.initial-access
  • attack.t1133

MITRE ATT&CK ids this rule names

Related rules

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/file/file_change/file_change_win_unusual_modification_by_dns_exe.yml

Sources and licences

  • SigmaHQ

    "Unusual File Modification by dns.exe" by Tim Rauch (Nextron Systems), Elastic (idea) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/file/file_change/file_change_win_unusual_modification_by_dns_exe.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Unusual File Modification by dns.exe",
entity page, dataset version ref-d781bade7df7, updated 2022-09-27T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/9f383dc0-fdeb-4d56-acbc-9f9f4f8f20f3 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 9f383dc0-fdeb-4d56-acbc-9f9f4f8f20f3, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.