Emerging Threathightest

UNC4841 - Download Compressed Files From Temp.sh Using Wget

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.

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Launch
Nasreddine Bencherchali (Nextron Systems)Created Fri Jun 1660d050c4-e253-4d9a-b673-5ac100cfddfb2023
Emerging Threat
Active Threat

Developed to detect an active or emerging threat. Prioritize investigation of any alerts and correlate with threat intelligence.

Log Source
LinuxProcess Creation
ProductLinux← raw: linux
CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic
Detection Logic1 selector
detection:
    selection:
        Image|endswith: '/wget'
        CommandLine|contains: 'https://temp.sh/'
        CommandLine|endswith:
            - '.rar'
            - '.zip'
    condition: selection
False Positives
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

MITRE ATT&CK
Rule Metadata
Rule ID
60d050c4-e253-4d9a-b673-5ac100cfddfb
Status
test
Level
high
Type
Emerging Threat
Created
Fri Jun 16
Path
rules-emerging-threats/2023/TA/UNC4841-Barracuda-ESG-Zero-Day-Exploitation/proc_creation_lnx_apt_unc4841_wget_download_compressed_file_tmep_sh.yml
Raw Tags
attack.defense-evasionattack.t1140detection.emerging-threats
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