Download From Suspicious TLD - Blacklist (via proxy)

This rule detects download of certain file types from hosts in anomalous TLDs

SigmalowWebv1
sigma
title: Download From Suspicious TLD - Blacklist (via proxy)
id: f5a58843-e975-5c40-9fac-23cfdf953591
status: stable
description: This rule detects download of certain file types from hosts in anomalous TLDs
references:
    - https://attack.mitre.org/techniques/T1204/002/
    - https://attack.mitre.org/techniques/T1203/
    - https://attack.mitre.org/techniques/T1566/
    - https://www.symantec.com/connect/blogs/shady-tld-research-gdn-and-our-2016-wrap
    - https://promos.mcafee.com/en-US/PDF/MTMW_Report.pdf
    - https://www.spamhaus.org/statistics/tlds/
    - https://krebsonsecurity.com/2018/06/bad-men-at-work-please-dont-click/
author: Huntrule Team
date: 2026-03-19
tags:
    - attack.initial-access
    - attack.t1566
    - attack.execution
    - attack.t1203
    - attack.t1204.002
logsource:
    category: proxy
detection:
    selection:
        c-uri-extension:
            - 'exe'
            - 'vbs'
            - 'bat'
            - 'rar'
            - 'ps1'
            - 'doc'
            - 'docm'
            - 'xls'
            - 'xlsm'
            - 'pptm'
            - 'rtf'
            - 'hta'
            - 'dll'
            - 'ws'
            - 'wsf'
            - 'sct'
            - 'zip'
        cs-host|endswith:
            - '.country'
            - '.stream'
            - '.gdn'
            - '.mom'
            - '.xin'
            - '.kim'
            - '.men'
            - '.loan'
            - '.download'
            - '.racing'
            - '.online'
            - '.science'
            - '.ren'
            - '.gb'
            - '.win'
            - '.top'
            - '.review'
            - '.vip'
            - '.party'
            - '.tech'
            - '.xyz'
            - '.date'
            - '.faith'
            - '.zip'
            - '.cricket'
            - '.space'
            - '.info'
            - '.vn'
            - '.cm'
            - '.am'
            - '.cc'
            - '.asia'
            - '.ws'
            - '.tk'
            - '.biz'
            - '.su'
            - '.st'
            - '.ro'
            - '.ge'
            - '.ms'
            - '.pk'
            - '.nu'
            - '.me'
            - '.ph'
            - '.to'
            - '.tt'
            - '.name'
            - '.tv'
            - '.kz'
            - '.tc'
            - '.mobi'
            - '.study'
            - '.click'
            - '.link'
            - '.trade'
            - '.accountant'
            - '.cf'
            - '.gq'
            - '.ml'
            - '.ga'
            - '.pw'
    condition: selection
falsepositives:
    - Unknown
level: low

Known false positives

  • Unknown

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.