Detection rules › Sigma

Network Connection Initiated From Process Located In Potentially Suspicious Or Uncommon Location

Status
test
Severity
high
Log source
product windows, category network_connection
Author
Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects a network connection initiated by programs or processes running from suspicious or uncommon files system locations.

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1105 Ingress Tool Transfer

Event coverage

ProviderEventTitle
SysmonEvent ID 3Network connection

Rule body yaml

title: Network Connection Initiated From Process Located In Potentially Suspicious Or Uncommon Location
id: 7b434893-c57d-4f41-908d-6a17bf1ae98f
status: test
description: |
    Detects a network connection initiated by programs or processes running from suspicious or uncommon files system locations.
references:
    - https://docs.google.com/spreadsheets/d/17pSTDNpa0sf6pHeRhusvWG6rThciE8CsXTSlDUAZDyo
author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2017-03-19
modified: 2025-12-10
tags:
    - attack.command-and-control
    - attack.t1105
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        Image|contains:
            - ':\$Recycle.bin'
            - ':\Perflogs\'
            - ':\Temp\'
            - ':\Users\Default\'
            - ':\Users\Public\'
            - ':\Windows\Fonts\'
            - ':\Windows\IME\'
            - ':\Windows\System32\Tasks\'
            - ':\Windows\Tasks\'
            - '\config\systemprofile\'
            - '\Contacts\'
            - '\Favorites\'
            - '\Favourites\'
            - '\Music\'
            - '\Pictures\'
            - '\Videos\'
            - '\Windows\addins\'
    filter_main_domains:
        # Note: We exclude these domains to avoid duplicate filtering from e0f8ab85-0ac9-423b-a73a-81b3c7b1aa97
        DestinationHostname|endswith:
            - '.githubusercontent.com'       # Includes both gists and github repositories / Michael Haag (idea)
            - 'anonfiles.com'
            - 'cdn.discordapp.com'
            - 'ddns.net'
            - 'dl.dropboxusercontent.com'
            - 'ghostbin.co'
            - 'github.com'
            - 'glitch.me'
            - 'gofile.io'
            - 'hastebin.com'
            - 'mediafire.com'
            - 'mega.co.nz'
            - 'mega.nz'
            - 'onrender.com'
            - 'pages.dev'
            - 'paste.ee'
            - 'pastebin.com'
            - 'pastebin.pl'
            - 'pastetext.net'
            - 'portmap.io'  # https://pro.twitter.com/JaromirHorejsi/status/1795001037746761892/photo/2
            - 'privatlab.com'
            - 'privatlab.net'
            - 'send.exploit.in'
            - 'sendspace.com'
            - 'storage.googleapis.com'
            - 'storjshare.io'
            - 'supabase.co'
            - 'temp.sh'
            - 'transfer.sh'
            - 'trycloudflare.com'
            - 'ufile.io'
            - 'w3spaces.com'
            - 'workers.dev'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    Initiated: 'true'
    Image|contains:
        - ':\$Recycle.bin'
        - ':\Perflogs\'
        - ':\Temp\'
        - ':\Users\Default\'
        - ':\Users\Public\'
        - ':\Windows\Fonts\'
        - ':\Windows\IME\'
        - ':\Windows\System32\Tasks\'
        - ':\Windows\Tasks\'
        - '\config\systemprofile\'
        - '\Contacts\'
        - '\Favorites\'
        - '\Favourites\'
        - '\Music\'
        - '\Pictures\'
        - '\Videos\'
        - '\Windows\addins\'

Stage 2: not filter_main_domains

filter_main_domains:
    DestinationHostname|endswith:
        - '.githubusercontent.com'
        - 'anonfiles.com'
        - 'cdn.discordapp.com'
        - 'ddns.net'
        - 'dl.dropboxusercontent.com'
        - 'ghostbin.co'
        - 'github.com'
        - 'glitch.me'
        - 'gofile.io'
        - 'hastebin.com'
        - 'mediafire.com'
        - 'mega.co.nz'
        - 'mega.nz'
        - 'onrender.com'
        - 'pages.dev'
        - 'paste.ee'
        - 'pastebin.com'
        - 'pastebin.pl'
        - 'pastetext.net'
        - 'portmap.io'
        - 'privatlab.com'
        - 'privatlab.net'
        - 'send.exploit.in'
        - 'sendspace.com'
        - 'storage.googleapis.com'
        - 'storjshare.io'
        - 'supabase.co'
        - 'temp.sh'
        - 'transfer.sh'
        - 'trycloudflare.com'
        - 'ufile.io'
        - 'w3spaces.com'
        - 'workers.dev'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
DestinationHostnameends_with.githubusercontent.com
DestinationHostnameends_withanonfiles.com
DestinationHostnameends_withcdn.discordapp.com
DestinationHostnameends_withddns.net
DestinationHostnameends_withdl.dropboxusercontent.com
DestinationHostnameends_withghostbin.co
DestinationHostnameends_withgithub.com
DestinationHostnameends_withglitch.me
DestinationHostnameends_withgofile.io
DestinationHostnameends_withhastebin.com
DestinationHostnameends_withmediafire.com
DestinationHostnameends_withmega.co.nz
DestinationHostnameends_withmega.nz
DestinationHostnameends_withonrender.com
DestinationHostnameends_withpages.dev
DestinationHostnameends_withpaste.ee
DestinationHostnameends_withpastebin.com
DestinationHostnameends_withpastebin.pl
DestinationHostnameends_withpastetext.net
DestinationHostnameends_withportmap.io
DestinationHostnameends_withprivatlab.com
DestinationHostnameends_withprivatlab.net
DestinationHostnameends_withsend.exploit.in
DestinationHostnameends_withsendspace.com
DestinationHostnameends_withstorage.googleapis.com
DestinationHostnameends_withstorjshare.io
DestinationHostnameends_withsupabase.co
DestinationHostnameends_withtemp.sh
DestinationHostnameends_withtransfer.sh
DestinationHostnameends_withtrycloudflare.com
DestinationHostnameends_withufile.io
DestinationHostnameends_withw3spaces.com
DestinationHostnameends_withworkers.dev

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imagematch
  • :\$Recycle.bin corpus 2 (sigma 2)
  • :\Perflogs\ corpus 10 (sigma 10)
  • :\Temp\ corpus 13 (sigma 13)
  • :\Users\Default\ corpus 3 (sigma 3)
  • :\Users\Public\ corpus 15 (sigma 15)
  • :\Windows\Fonts\ corpus 3 (sigma 3)
  • :\Windows\IME\ corpus 3 (sigma 3)
  • :\Windows\System32\Tasks\ corpus 4 (sigma 4)
  • :\Windows\Tasks\ corpus 5 (sigma 5)
  • \Contacts\ corpus 5 (sigma 5)
  • \Favorites\ corpus 6 (sigma 6)
  • \Favourites\ corpus 5 (sigma 5)
  • \Music\ corpus 4 (sigma 4)
  • \Pictures\ corpus 5 (sigma 5)
  • \Videos\ corpus 4 (sigma 4)
  • \Windows\addins\ corpus 4 (sigma 4)
  • \config\systemprofile\ corpus 4 (sigma 4)
Initiatedeq
  • true corpus 50 (sigma 50)