Sigma rule: Suspicious Network Connection to IP Lookup Service APIs

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-329c19acc5c7, updated 2024-03-22T00:00:00.000Z.

Rule

Title
Suspicious Network Connection to IP Lookup Service APIs
Status
test
Level
medium
Author
Janantha Marasinghe, Nasreddine Bencherchali (Nextron Systems)
Date
2023-04-24
Modified
2024-03-22
File
rules/windows/network_connection/net_connection_win_domain_external_ip_lookup.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects external IP address lookups by non-browser processes via services such as "api.ipify.org". This could be indicative of potential post compromise internet test activity.

Log source

product
windows
category
network_connection

Detection

selection:
    - DestinationHostname:
          - 'www.ip.cn'
          - 'l2.io'
    - DestinationHostname|contains:
          - 'api.2ip.ua'
          - 'api.bigdatacloud.net'
          - 'api.ipify.org'
          - 'bot.whatismyipaddress.com'
          - 'canireachthe.net'
          - 'checkip.amazonaws.com'
          - 'checkip.dyndns.org'
          - 'curlmyip.com'
          - 'db-ip.com'
          - 'edns.ip-api.com'
          - 'eth0.me'
          - 'freegeoip.app'
          - 'geoipy.com'
          - 'getip.pro'
          - 'icanhazip.com'
          - 'ident.me'
          - 'ifconfig.io'
          - 'ifconfig.me'
          - 'ip-api.com'
          - 'ip.360.cn'
          - 'ip.anysrc.net'
          - 'ip.taobao.com'
          - 'ip.tyk.nu'
          - 'ipaddressworld.com'
          - 'ipapi.co'
          - 'ipconfig.io'
          - 'ipecho.net'
          - 'ipinfo.io'
          - 'ipip.net'
          - 'ipof.in'
          - 'ipv4.icanhazip.com'
          - 'ipv4bot.whatismyipaddress.com'
          - 'ipv6-test.com'
          - 'ipwho.is'
          - 'jsonip.com'
          - 'myexternalip.com'
          - 'seeip.org'
          - 'wgetip.com'
          - 'whatismyip.akamai.com'
          - 'whois.pconline.com.cn'
          - 'wtfismyip.com'
filter_optional_brave:
    Image|endswith: '\brave.exe'
filter_optional_chrome:
    Image:
        - 'C:\Program Files\Google\Chrome\Application\chrome.exe'
        - 'C:\Program Files (x86)\Google\Chrome\Application\chrome.exe'
filter_optional_firefox:
    Image:
        - 'C:\Program Files\Mozilla Firefox\firefox.exe'
        - 'C:\Program Files (x86)\Mozilla Firefox\firefox.exe'
filter_optional_ie:
    Image:
        - 'C:\Program Files (x86)\Internet Explorer\iexplore.exe'
        - 'C:\Program Files\Internet Explorer\iexplore.exe'
filter_optional_maxthon:
    Image|endswith: '\maxthon.exe'
filter_optional_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_optional_edge_2:
    Image|startswith:
        - 'C:\Program Files (x86)\Microsoft\EdgeCore\'
        - 'C:\Program Files\Microsoft\EdgeCore\'
    Image|endswith:
        - '\msedge.exe'
        - '\msedgewebview2.exe'
filter_optional_opera:
    Image|endswith: '\opera.exe'
filter_optional_safari:
    Image|endswith: '\safari.exe'
filter_optional_seamonkey:
    Image|endswith: '\seamonkey.exe'
filter_optional_vivaldi:
    Image|endswith: '\vivaldi.exe'
filter_optional_whale:
    Image|endswith: '\whale.exe'
condition: selection and not 1 of filter_optional_*

False positives (as the rule lists them)

  • Legitimate use of the external websites for troubleshooting or network monitoring

Tags

  • attack.discovery
  • attack.t1016

MITRE ATT&CK ids this rule names

Related rules

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/windows/network_connection/net_connection_win_domain_external_ip_lookup.yml

Sources and licences

  • SigmaHQ

    "Suspicious Network Connection to IP Lookup Service APIs" by Janantha Marasinghe, Nasreddine Bencherchali (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/network_connection/net_connection_win_domain_external_ip_lookup.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: Suspicious Network Connection to IP Lookup Service APIs",
entity page, dataset version ref-329c19acc5c7, updated 2024-03-22T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/edf3485d-dac4-4d50-90e4-b0e5813f7e60 (accessed 2026-11-03).
Underlying source: SigmaHQ rule edf3485d-dac4-4d50-90e4-b0e5813f7e60, 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.