New Connection Initiated To Potential Dead Drop Resolver Domain

Status: test
Severity: high
Log source: product windows, category network_connection
Author: Sorina Ionescu, X__Junior (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects an executable, which is not an internet browser or known application, initiating network connections to legit popular websites, which were seen to be used as dead drop resolvers in previous attacks. In this context attackers leverage known websites such as "facebook", "youtube", etc. In order to pass through undetected.

MITRE ATT&CK coverage

Tactic	Techniques
Command & Control	`T1102.001` Web Service: Dead Drop Resolver

Event coverage

Provider	Event	Title
Sysmon	Event ID 3	Network connection

Rule body yaml

title: New Connection Initiated To Potential Dead Drop Resolver Domain
id: 297ae038-edc2-4b2e-bb3e-7c5fc94dd5c7
related:
    - id: d7b09985-95a3-44be-8450-b6eadf49833e
      type: obsolete
status: test
description: |
    Detects an executable, which is not an internet browser or known application, initiating network connections to legit popular websites, which were seen to be used as dead drop resolvers in previous attacks.
    In this context attackers leverage known websites such as "facebook", "youtube", etc. In order to pass through undetected.
references:
    - https://web.archive.org/web/20220830134315/https://content.fireeye.com/apt-41/rpt-apt41/
    - https://securelist.com/the-tetrade-brazilian-banking-malware/97779/
    - https://blog.bushidotoken.net/2021/04/dead-drop-resolvers-espionage-inspired.html
    - https://github.com/kleiton0x00/RedditC2
    - https://twitter.com/kleiton0x7e/status/1600567316810551296
    - https://www.linkedin.com/posts/kleiton-kurti_github-kleiton0x00redditc2-abusing-reddit-activity-7009939662462984192-5DbI/?originalSubdomain=al
author: Sorina Ionescu, X__Junior (Nextron Systems)
date: 2022-08-17
modified: 2024-10-21
tags:
    - attack.command-and-control
    - attack.t1102
    - attack.t1102.001
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        DestinationHostname|endswith:
            - '.t.me'
            - '4shared.com'
            - 'abuse.ch'
            - 'anonfiles.com'
            - 'cdn.discordapp.com'
            - 'cloudflare.com'
            - 'ddns.net'
            - 'discord.com'
            - 'docs.google.com'
            - 'drive.google.com'
            - 'dropbox.com'
            - 'dropmefiles.com'
            - 'facebook.com'
            - 'feeds.rapidfeeds.com'
            - 'fotolog.com'
            - 'ghostbin.co/'
            - 'githubusercontent.com'
            - 'gofile.io'
            - 'hastebin.com'
            - 'imgur.com'
            - 'livejournal.com'
            - 'mediafire.com'
            - 'mega.co.nz'
            - 'mega.nz'
            - 'onedrive.com'
            - 'pages.dev'
            - 'paste.ee'
            - 'pastebin.com'
            - 'pastebin.pl'
            - 'pastetext.net'
            - 'pixeldrain.com'
            - 'privatlab.com'
            - 'privatlab.net'
            - 'reddit.com'
            - 'send.exploit.in'
            - 'sendspace.com'
            - 'steamcommunity.com'
            - 'storage.googleapis.com'
            - 'technet.microsoft.com'
            - 'temp.sh'
            - 'transfer.sh'
            - 'trycloudflare.com'
            - 'twitter.com'
            - 'ufile.io'
            - 'vimeo.com'
            - 'w3spaces.com'
            - 'wetransfer.com'
            - 'workers.dev'
            - 'youtube.com'
    # Note: Add/Remove browsers/applications that you don't use or those that have custom install locations
    # Note: To avoid complex conditions the filters for some apps are generic by name only. A custom tuning is recommended for best results
    filter_main_chrome:
        Image:
            - 'C:\Program Files\Google\Chrome\Application\chrome.exe'
            - 'C:\Program Files (x86)\Google\Chrome\Application\chrome.exe'
    filter_main_chrome_appdata:
        Image|startswith: 'C:\Users\'
        Image|endswith: '\AppData\Local\Google\Chrome\Application\chrome.exe'
    filter_main_firefox:
        Image:
            - 'C:\Program Files\Mozilla Firefox\firefox.exe'
            - 'C:\Program Files (x86)\Mozilla Firefox\firefox.exe'
    filter_main_firefox_appdata:
        Image|startswith: 'C:\Users\'
        Image|endswith: '\AppData\Local\Mozilla Firefox\firefox.exe'
    filter_main_ie:
        Image:
            - 'C:\Program Files (x86)\Internet Explorer\iexplore.exe'
            - 'C:\Program Files\Internet Explorer\iexplore.exe'
    filter_main_edge_1:
        - Image|startswith: 'C:\Program Files (x86)\Microsoft\EdgeWebView\Application\'
        - Image|endswith: '\WindowsApps\MicrosoftEdge.exe'
        - Image:
              - 'C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe'
              - 'C:\Program Files\Microsoft\Edge\Application\msedge.exe'
    filter_main_edge_2:
        Image|startswith:
            - 'C:\Program Files (x86)\Microsoft\EdgeCore\'
            - 'C:\Program Files\Microsoft\EdgeCore\'
        Image|endswith:
            - '\msedge.exe'
            - '\msedgewebview2.exe'
    filter_main_safari:
        Image|contains:
            - 'C:\Program Files (x86)\Safari\'
            - 'C:\Program Files\Safari\'
        Image|endswith: '\safari.exe'
    filter_main_defender:
        Image|contains:
            - 'C:\Program Files\Windows Defender Advanced Threat Protection\'
            - 'C:\Program Files\Windows Defender\'
            - 'C:\ProgramData\Microsoft\Windows Defender\Platform\'
        Image|endswith:
            - '\MsMpEng.exe' # Microsoft Defender executable
            - '\MsSense.exe' # Windows Defender Advanced Threat Protection Service Executable
    filter_main_prtg:
        # Paessler's PRTG Network Monitor
        Image|endswith:
            - 'C:\Program Files (x86)\PRTG Network Monitor\PRTG Probe.exe'
            - 'C:\Program Files\PRTG Network Monitor\PRTG Probe.exe'
    filter_main_brave:
        Image|startswith: 'C:\Program Files\BraveSoftware\'
        Image|endswith: '\brave.exe'
    filter_main_maxthon:
        Image|contains: '\AppData\Local\Maxthon\'
        Image|endswith: '\maxthon.exe'
    filter_main_opera:
        Image|contains: '\AppData\Local\Programs\Opera\'
        Image|endswith: '\opera.exe'
    filter_main_seamonkey:
        Image|startswith:
            - 'C:\Program Files\SeaMonkey\'
            - 'C:\Program Files (x86)\SeaMonkey\'
        Image|endswith: '\seamonkey.exe'
    filter_main_vivaldi:
        Image|contains: '\AppData\Local\Vivaldi\'
        Image|endswith: '\vivaldi.exe'
    filter_main_whale:
        Image|startswith:
            - 'C:\Program Files\Naver\Naver Whale\'
            - 'C:\Program Files (x86)\Naver\Naver Whale\'
        Image|endswith: '\whale.exe'
    # Note: The TOR browser shouldn't be something you allow in your corporate network.
    # filter_main_tor:
    #     Image|contains: '\Tor Browser\'
    filter_main_whaterfox:
        Image|startswith:
            - 'C:\Program Files\Waterfox\'
            - 'C:\Program Files (x86)\Waterfox\'
        Image|endswith: '\Waterfox.exe'
    filter_main_midori:
        Image|contains: '\AppData\Local\Programs\midori-ng\'
        Image|endswith: '\Midori Next Generation.exe'
    filter_main_slimbrowser:
        Image|startswith:
            - 'C:\Program Files\SlimBrowser\'
            - 'C:\Program Files (x86)\SlimBrowser\'
        Image|endswith: '\slimbrowser.exe'
    filter_main_flock:
        Image|contains: '\AppData\Local\Flock\'
        Image|endswith: '\Flock.exe'
    filter_main_phoebe:
        Image|contains: '\AppData\Local\Phoebe\'
        Image|endswith: '\Phoebe.exe'
    filter_main_falkon:
        Image|startswith:
            - 'C:\Program Files\Falkon\'
            - 'C:\Program Files (x86)\Falkon\'
        Image|endswith: '\falkon.exe'
    filter_main_qtweb:
        Image|startswith:
            - 'C:\Program Files (x86)\QtWeb\'
            - 'C:\Program Files\QtWeb\'
        Image|endswith: '\QtWeb.exe'
    filter_main_avant:
        Image|startswith:
            - 'C:\Program Files (x86)\Avant Browser\'
            - 'C:\Program Files\Avant Browser\'
        Image|endswith: '\avant.exe'
    filter_main_whatsapp:
        Image|startswith:
            - 'C:\Program Files (x86)\WindowsApps\'
            - 'C:\Program Files\WindowsApps\'
        Image|endswith: '\WhatsApp.exe'
        DestinationHostname|endswith: 'facebook.com'
    filter_main_telegram:
        Image|contains: '\AppData\Roaming\Telegram Desktop\'
        Image|endswith: '\Telegram.exe'
        DestinationHostname|endswith: '.t.me'
    filter_main_onedrive:
        Image|contains: '\AppData\Local\Microsoft\OneDrive\'
        Image|endswith: '\OneDrive.exe'
        DestinationHostname|endswith: 'onedrive.com'
    filter_main_dropbox:
        Image|startswith:
            - 'C:\Program Files (x86)\Dropbox\Client\'
            - 'C:\Program Files\Dropbox\Client\'
        Image|endswith:
            - '\Dropbox.exe'
            - '\DropboxInstaller.exe'
        DestinationHostname|endswith: 'dropbox.com'
    filter_main_mega:
        Image|endswith:
            # Note: This is a basic/best effort filter in order to avoid FP with the MEGA installer and executable.
            #       In practice please apply exact path to avoid basic path bypass techniques.
            - '\MEGAsync.exe'
            - '\MEGAsyncSetup32_*RC.exe' # Beta versions
            - '\MEGAsyncSetup32.exe' # Installers 32bit
            - '\MEGAsyncSetup64.exe' # Installers 64bit
            - '\MEGAupdater.exe'
        DestinationHostname|endswith:
            - 'mega.co.nz'
            - 'mega.nz'
    filter_main_googledrive:
        Image|contains:
            - 'C:\Program Files\Google\Drive File Stream\'
            - 'C:\Program Files (x86)\Google\Drive File Stream\'
        Image|endswith: 'GoogleDriveFS.exe'
        DestinationHostname|endswith: 'drive.google.com'
    filter_main_discord:
        Image|contains: '\AppData\Local\Discord\'
        Image|endswith: '\Discord.exe'
        DestinationHostname|endswith:
            - 'discord.com'
            - 'cdn.discordapp.com'
    filter_main_null:
        Image: null
    filter_main_empty:
        Image: ''
    # filter_optional_qlik:
    #     Image|endswith: '\Engine.exe' # Process from qlik.com app
    condition: selection and not 1 of filter_main_*
falsepositives:
    - One might need to exclude other internet browsers found in it's network or other applications like ones mentioned above from Microsoft Defender.
    - Ninite contacting githubusercontent.com
level: high

Stages and Predicates

Stage 0: `condition`

selection and not 1 of filter_main_*

Stage 1: `selection`

selection:
    Initiated: 'true'
    DestinationHostname|endswith:
        - '.t.me'
        - '4shared.com'
        - 'abuse.ch'
        - 'anonfiles.com'
        - 'cdn.discordapp.com'
        - 'cloudflare.com'
        - 'ddns.net'
        - 'discord.com'
        - 'docs.google.com'
        - 'drive.google.com'
        - 'dropbox.com'
        - 'dropmefiles.com'
        - 'facebook.com'
        - 'feeds.rapidfeeds.com'
        - 'fotolog.com'
        - 'ghostbin.co/'
        - 'githubusercontent.com'
        - 'gofile.io'
        - 'hastebin.com'
        - 'imgur.com'
        - 'livejournal.com'
        - 'mediafire.com'
        - 'mega.co.nz'
        - 'mega.nz'
        - 'onedrive.com'
        - 'pages.dev'
        - 'paste.ee'
        - 'pastebin.com'
        - 'pastebin.pl'
        - 'pastetext.net'
        - 'pixeldrain.com'
        - 'privatlab.com'
        - 'privatlab.net'
        - 'reddit.com'
        - 'send.exploit.in'
        - 'sendspace.com'
        - 'steamcommunity.com'
        - 'storage.googleapis.com'
        - 'technet.microsoft.com'
        - 'temp.sh'
        - 'transfer.sh'
        - 'trycloudflare.com'
        - 'twitter.com'
        - 'ufile.io'
        - 'vimeo.com'
        - 'w3spaces.com'
        - 'wetransfer.com'
        - 'workers.dev'
        - 'youtube.com'

Stage 2: `not filter_main_*`

filter_main_chrome:
    Image:
        - 'C:\Program Files\Google\Chrome\Application\chrome.exe'
        - 'C:\Program Files (x86)\Google\Chrome\Application\chrome.exe'
filter_main_chrome_appdata:
    Image|startswith: 'C:\Users\'
    Image|endswith: '\AppData\Local\Google\Chrome\Application\chrome.exe'
filter_main_firefox:
    Image:
        - 'C:\Program Files\Mozilla Firefox\firefox.exe'
        - 'C:\Program Files (x86)\Mozilla Firefox\firefox.exe'
filter_main_firefox_appdata:
    Image|startswith: 'C:\Users\'
    Image|endswith: '\AppData\Local\Mozilla Firefox\firefox.exe'
filter_main_ie:
    Image:
        - 'C:\Program Files (x86)\Internet Explorer\iexplore.exe'
        - 'C:\Program Files\Internet Explorer\iexplore.exe'
filter_main_edge_1:
    - Image|startswith: 'C:\Program Files (x86)\Microsoft\EdgeWebView\Application\'
    - Image|endswith: '\WindowsApps\MicrosoftEdge.exe'
    - Image:
          - 'C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe'
          - 'C:\Program Files\Microsoft\Edge\Application\msedge.exe'
filter_main_edge_2:
    Image|startswith:
        - 'C:\Program Files (x86)\Microsoft\EdgeCore\'
        - 'C:\Program Files\Microsoft\EdgeCore\'
    Image|endswith:
        - '\msedge.exe'
        - '\msedgewebview2.exe'
filter_main_safari:
    Image|contains:
        - 'C:\Program Files (x86)\Safari\'
        - 'C:\Program Files\Safari\'
    Image|endswith: '\safari.exe'
filter_main_defender:
    Image|contains:
        - 'C:\Program Files\Windows Defender Advanced Threat Protection\'
        - 'C:\Program Files\Windows Defender\'
        - 'C:\ProgramData\Microsoft\Windows Defender\Platform\'
    Image|endswith:
        - '\MsMpEng.exe'
        - '\MsSense.exe'
filter_main_prtg:
    Image|endswith:
        - 'C:\Program Files (x86)\PRTG Network Monitor\PRTG Probe.exe'
        - 'C:\Program Files\PRTG Network Monitor\PRTG Probe.exe'
filter_main_brave:
    Image|startswith: 'C:\Program Files\BraveSoftware\'
    Image|endswith: '\brave.exe'
filter_main_maxthon:
    Image|contains: '\AppData\Local\Maxthon\'
    Image|endswith: '\maxthon.exe'
filter_main_opera:
    Image|contains: '\AppData\Local\Programs\Opera\'
    Image|endswith: '\opera.exe'
filter_main_seamonkey:
    Image|startswith:
        - 'C:\Program Files\SeaMonkey\'
        - 'C:\Program Files (x86)\SeaMonkey\'
    Image|endswith: '\seamonkey.exe'
filter_main_vivaldi:
    Image|contains: '\AppData\Local\Vivaldi\'
    Image|endswith: '\vivaldi.exe'
filter_main_whale:
    Image|startswith:
        - 'C:\Program Files\Naver\Naver Whale\'
        - 'C:\Program Files (x86)\Naver\Naver Whale\'
    Image|endswith: '\whale.exe'
filter_main_whaterfox:
    Image|startswith:
        - 'C:\Program Files\Waterfox\'
        - 'C:\Program Files (x86)\Waterfox\'
    Image|endswith: '\Waterfox.exe'
filter_main_midori:
    Image|contains: '\AppData\Local\Programs\midori-ng\'
    Image|endswith: '\Midori Next Generation.exe'
filter_main_slimbrowser:
    Image|startswith:
        - 'C:\Program Files\SlimBrowser\'
        - 'C:\Program Files (x86)\SlimBrowser\'
    Image|endswith: '\slimbrowser.exe'
filter_main_flock:
    Image|contains: '\AppData\Local\Flock\'
    Image|endswith: '\Flock.exe'
filter_main_phoebe:
    Image|contains: '\AppData\Local\Phoebe\'
    Image|endswith: '\Phoebe.exe'
filter_main_falkon:
    Image|startswith:
        - 'C:\Program Files\Falkon\'
        - 'C:\Program Files (x86)\Falkon\'
    Image|endswith: '\falkon.exe'
filter_main_qtweb:
    Image|startswith:
        - 'C:\Program Files (x86)\QtWeb\'
        - 'C:\Program Files\QtWeb\'
    Image|endswith: '\QtWeb.exe'
filter_main_avant:
    Image|startswith:
        - 'C:\Program Files (x86)\Avant Browser\'
        - 'C:\Program Files\Avant Browser\'
    Image|endswith: '\avant.exe'
filter_main_whatsapp:
    Image|startswith:
        - 'C:\Program Files (x86)\WindowsApps\'
        - 'C:\Program Files\WindowsApps\'
    Image|endswith: '\WhatsApp.exe'
    DestinationHostname|endswith: 'facebook.com'
filter_main_telegram:
    Image|contains: '\AppData\Roaming\Telegram Desktop\'
    Image|endswith: '\Telegram.exe'
    DestinationHostname|endswith: '.t.me'
filter_main_onedrive:
    Image|contains: '\AppData\Local\Microsoft\OneDrive\'
    Image|endswith: '\OneDrive.exe'
    DestinationHostname|endswith: 'onedrive.com'
filter_main_dropbox:
    Image|startswith:
        - 'C:\Program Files (x86)\Dropbox\Client\'
        - 'C:\Program Files\Dropbox\Client\'
    Image|endswith:
        - '\Dropbox.exe'
        - '\DropboxInstaller.exe'
    DestinationHostname|endswith: 'dropbox.com'
filter_main_mega:
    Image|endswith:
        - '\MEGAsync.exe'
        - '\MEGAsyncSetup32_*RC.exe'
        - '\MEGAsyncSetup32.exe'
        - '\MEGAsyncSetup64.exe'
        - '\MEGAupdater.exe'
    DestinationHostname|endswith:
        - 'mega.co.nz'
        - 'mega.nz'
filter_main_googledrive:
    Image|contains:
        - 'C:\Program Files\Google\Drive File Stream\'
        - 'C:\Program Files (x86)\Google\Drive File Stream\'
    Image|endswith: 'GoogleDriveFS.exe'
    DestinationHostname|endswith: 'drive.google.com'
filter_main_discord:
    Image|contains: '\AppData\Local\Discord\'
    Image|endswith: '\Discord.exe'
    DestinationHostname|endswith:
        - 'discord.com'
        - 'cdn.discordapp.com'
filter_main_null:
    Image: null
filter_main_empty:
    Image: ''

Exclusions

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

Field	Kind	Excluded values
`DestinationHostname`	ends_with	`cdn.discordapp.com`
`DestinationHostname`	ends_with	`discord.com`
`Image`	ends_with	`\Discord.exe`
`Image`	match	`\AppData\Local\Discord\`
`DestinationHostname`	ends_with	`mega.co.nz`
`DestinationHostname`	ends_with	`mega.nz`
`Image`	ends_with	`\MEGAsync.exe`
`Image`	ends_with	`\MEGAsyncSetup32.exe`
`Image`	ends_with	`\MEGAsyncSetup32_*RC.exe`
`Image`	ends_with	`\MEGAsyncSetup64.exe`
`Image`	ends_with	`\MEGAupdater.exe`
`Image`	ends_with	`\Dropbox.exe`
`Image`	ends_with	`\DropboxInstaller.exe`
`Image`	starts_with	`C:\Program Files (x86)\Dropbox\Client\`
`Image`	starts_with	`C:\Program Files\Dropbox\Client\`
`DestinationHostname`	ends_with	`dropbox.com`
`Image`	ends_with	`\MsMpEng.exe`
`Image`	ends_with	`\MsSense.exe`
`Image`	match	`C:\Program Files\Windows Defender Advanced Threat Protection\`
`Image`	match	`C:\Program Files\Windows Defender\`
`Image`	match	`C:\ProgramData\Microsoft\Windows Defender\Platform\`
`Image`	ends_with	`\msedge.exe`
`Image`	ends_with	`\msedgewebview2.exe`
`Image`	starts_with	`C:\Program Files (x86)\Microsoft\EdgeCore\`
`Image`	starts_with	`C:\Program Files\Microsoft\EdgeCore\`
`Image`	match	`C:\Program Files (x86)\Google\Drive File Stream\`
`Image`	match	`C:\Program Files\Google\Drive File Stream\`
`DestinationHostname`	ends_with	`drive.google.com`
`Image`	ends_with	`GoogleDriveFS.exe`
`Image`	match	`C:\Program Files (x86)\Safari\`
`Image`	match	`C:\Program Files\Safari\`
`Image`	ends_with	`\safari.exe`
`Image`	starts_with	`C:\Program Files (x86)\Avant Browser\`
`Image`	starts_with	`C:\Program Files\Avant Browser\`
`Image`	ends_with	`\avant.exe`
`Image`	starts_with	`C:\Program Files (x86)\Falkon\`
`Image`	starts_with	`C:\Program Files\Falkon\`
`Image`	ends_with	`\falkon.exe`
`Image`	starts_with	`C:\Program Files (x86)\Naver\Naver Whale\`
`Image`	starts_with	`C:\Program Files\Naver\Naver Whale\`
`Image`	ends_with	`\whale.exe`
`Image`	starts_with	`C:\Program Files (x86)\QtWeb\`
`Image`	starts_with	`C:\Program Files\QtWeb\`
`Image`	ends_with	`\QtWeb.exe`
`Image`	starts_with	`C:\Program Files (x86)\SeaMonkey\`
`Image`	starts_with	`C:\Program Files\SeaMonkey\`
`Image`	ends_with	`\seamonkey.exe`
`Image`	starts_with	`C:\Program Files (x86)\SlimBrowser\`
`Image`	starts_with	`C:\Program Files\SlimBrowser\`
`Image`	ends_with	`\slimbrowser.exe`
`Image`	starts_with	`C:\Program Files (x86)\Waterfox\`
`Image`	starts_with	`C:\Program Files\Waterfox\`
`Image`	ends_with	`\Waterfox.exe`
`Image`	starts_with	`C:\Program Files (x86)\WindowsApps\`
`Image`	starts_with	`C:\Program Files\WindowsApps\`
`DestinationHostname`	ends_with	`facebook.com`
`Image`	ends_with	`\WhatsApp.exe`
`DestinationHostname`	ends_with	`.t.me`
`Image`	ends_with	`\Telegram.exe`
`Image`	match	`\AppData\Roaming\Telegram Desktop\`
`DestinationHostname`	ends_with	`onedrive.com`
`Image`	ends_with	`\OneDrive.exe`
`Image`	match	`\AppData\Local\Microsoft\OneDrive\`
`Image`	ends_with	`\AppData\Local\Google\Chrome\Application\chrome.exe`
`Image`	starts_with	`C:\Users\`
`Image`	ends_with	`\AppData\Local\Mozilla Firefox\firefox.exe`
`Image`	starts_with	`C:\Users\`
`Image`	ends_with	`\Flock.exe`
`Image`	match	`\AppData\Local\Flock\`
`Image`	ends_with	`\Midori Next Generation.exe`
`Image`	match	`\AppData\Local\Programs\midori-ng\`
`Image`	ends_with	`\Phoebe.exe`
`Image`	match	`\AppData\Local\Phoebe\`
`Image`	ends_with	`\brave.exe`
`Image`	starts_with	`C:\Program Files\BraveSoftware\`
`Image`	ends_with	`\maxthon.exe`
`Image`	match	`\AppData\Local\Maxthon\`
`Image`	ends_with	`\opera.exe`
`Image`	match	`\AppData\Local\Programs\Opera\`
`Image`	ends_with	`\vivaldi.exe`
`Image`	match	`\AppData\Local\Vivaldi\`
`Image`	ends_with	`C:\Program Files (x86)\PRTG Network Monitor\PRTG Probe.exe`
`Image`	ends_with	`C:\Program Files\PRTG Network Monitor\PRTG Probe.exe`
`Image`	ends_with	`\WindowsApps\MicrosoftEdge.exe`
`Image`	eq	`C:\Program Files (x86)\Google\Chrome\Application\chrome.exe`
`Image`	eq	`C:\Program Files (x86)\Internet Explorer\iexplore.exe`
`Image`	eq	`C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe`
`Image`	eq	`C:\Program Files (x86)\Mozilla Firefox\firefox.exe`
`Image`	eq	`C:\Program Files\Google\Chrome\Application\chrome.exe`
`Image`	eq	`C:\Program Files\Internet Explorer\iexplore.exe`
`Image`	eq	`C:\Program Files\Microsoft\Edge\Application\msedge.exe`
`Image`	eq	`C:\Program Files\Mozilla Firefox\firefox.exe`
`Image`	is_null	(no value, null check)
`Image`	starts_with	`C:\Program Files (x86)\Microsoft\EdgeWebView\Application\`

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.

Field	Kind	Values
`DestinationHostname`	ends_with	`.t.me` `4shared.com` `abuse.ch` `anonfiles.com` corpus 2 (sigma 2) `cdn.discordapp.com` corpus 2 (sigma 2) `cloudflare.com` `ddns.net` corpus 2 (sigma 2) `discord.com` `docs.google.com` `drive.google.com` `dropbox.com` `dropmefiles.com` `facebook.com` `feeds.rapidfeeds.com` `fotolog.com` `ghostbin.co/` `githubusercontent.com` `gofile.io` corpus 2 (sigma 2) `hastebin.com` corpus 2 (sigma 2) `imgur.com` `livejournal.com` `mediafire.com` corpus 2 (sigma 2) `mega.co.nz` corpus 3 (sigma 3) `mega.nz` corpus 3 (sigma 3) `onedrive.com` `pages.dev` corpus 2 (sigma 2) `paste.ee` corpus 2 (sigma 2) `pastebin.com` corpus 2 (sigma 2) `pastebin.pl` corpus 2 (sigma 2) `pastetext.net` corpus 2 (sigma 2) `pixeldrain.com` corpus 2 (sigma 2) `privatlab.com` corpus 2 (sigma 2) `privatlab.net` corpus 2 (sigma 2) `reddit.com` `send.exploit.in` corpus 2 (sigma 2) `sendspace.com` corpus 2 (sigma 2) `steamcommunity.com` `storage.googleapis.com` corpus 2 (sigma 2) `technet.microsoft.com` `temp.sh` corpus 2 (sigma 2) `transfer.sh` corpus 2 (sigma 2) `trycloudflare.com` corpus 3 (sigma 3) `twitter.com` `ufile.io` corpus 2 (sigma 2) `vimeo.com` `w3spaces.com` corpus 2 (sigma 2) `wetransfer.com` `workers.dev` corpus 2 (sigma 2) `youtube.com`
`Initiated`	eq	`true` corpus 50 (sigma 50)

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

New Connection Initiated To Potential Dead Drop Resolver Domain

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection`

Stage 2: `not filter_main_*`

Exclusions

Indicators

Keyboard shortcuts

Search operators

New Connection Initiated To Potential Dead Drop Resolver Domain

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection

Stage 2: not filter_main_*

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection`

Stage 2: `not filter_main_*`