Sigma rule: UNC4841 - Download Compressed Files From Temp.sh Using Wget

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-9bc3d8fbeca8, updated 2023-06-16T00:00:00.000Z.

Rule

Title
UNC4841 - Download Compressed Files From Temp.sh Using Wget
Status
test
Level
high
Author
Nasreddine Bencherchali (Nextron Systems)
Date
2023-06-16
File
rules-emerging-threats/2023/TA/UNC4841-Barracuda-ESG-Zero-Day-Exploitation/proc_creation_lnx_apt_unc4841_wget_download_compressed_file_tmep_sh.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects execution of "wget" to download a ".zip" or ".rar" files from "temp.sh". As seen used by UNC4841 during their Barracuda ESG zero day exploitation.

Log source

product
linux
category
process_creation

Detection

selection:
    Image|endswith: '/wget'
    CommandLine|contains: 'https://temp.sh/'
    CommandLine|endswith:
        - '.rar'
        - '.zip'
condition: selection

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.stealth
  • attack.t1140
  • detection.emerging-threats

MITRE ATT&CK ids this rule names

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-emerging-threats/2023/TA/UNC4841-Barracuda-ESG-Zero-Day-Exploitation/proc_creation_lnx_apt_unc4841_wget_download_compressed_file_tmep_sh.yml

Sources and licences

  • SigmaHQ

    "UNC4841 - Download Compressed Files From Temp.sh Using Wget" by Nasreddine Bencherchali (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2023/TA/UNC4841-Barracuda-ESG-Zero-Day-Exploitation/proc_creation_lnx_apt_unc4841_wget_download_compressed_file_tmep_sh.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: UNC4841 - Download Compressed Files From Temp.sh Using Wget",
entity page, dataset version ref-9bc3d8fbeca8, updated 2023-06-16T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/60d050c4-e253-4d9a-b673-5ac100cfddfb (accessed 2026-11-03).
Underlying source: SigmaHQ rule 60d050c4-e253-4d9a-b673-5ac100cfddfb, 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.