Suspicious Network Connection to IP Lookup Service APIs

 1title: Suspicious Network Connection to IP Lookup Service APIs
 2id: edf3485d-dac4-4d50-90e4-b0e5813f7e60
 3related:
 4    - id: ec82e2a5-81ea-4211-a1f8-37a0286df2c2
 5      type: derived
 6status: experimental
 7description: 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.
 8references:
 9    - https://github.com/rsp/scripts/blob/c8bb272d68164a9836e4f273d8f924927f39b8c6/externalip-benchmark.md
10    - https://www.cisa.gov/news-events/cybersecurity-advisories/aa20-302a
11    - https://thedfirreport.com/2022/11/28/emotet-strikes-again-lnk-file-leads-to-domain-wide-ransomware/
12    - https://www.trendmicro.com/en_us/research/23/e/managed-xdr-investigation-of-ducktail-in-trend-micro-vision-one.html
13author: Janantha Marasinghe, Nasreddine Bencherchali (Nextron Systems)
14date: 2023/04/24
15modified: 2023/05/12
16tags:
17    - attack.discovery
18    - attack.t1016
19logsource:
20    category: network_connection
21    product: windows
22detection:
23    selection:
24        DestinationHostname|contains:
25            - 'api.2ip.ua'
26            - 'api.ipify.org'
27            - 'bot.whatismyipaddress.com'
28            - 'canireachthe.net'
29            - 'checkip.amazonaws.com'
30            - 'checkip.dyndns.org'
31            - 'curlmyip.com'
32            - 'edns.ip-api.com'
33            - 'eth0.me'
34            - 'freegeoip.app'
35            - 'geoipy.com'
36            - 'getip.pro'
37            - 'icanhazip.com'
38            - 'ident.me'
39            - 'ifconfig.io'
40            - 'ifconfig.me'
41            - 'ip-api.com'
42            - 'ip.anysrc.net'
43            - 'ip.tyk.nu'
44            - 'ipaddressworld.com'
45            - 'ipecho.net'
46            - 'ipinfo.io'
47            - 'ipof.in'
48            - 'ipv4.icanhazip.com'
49            - 'ipv4bot.whatismyipaddress.com'
50            - 'ipwho.is'
51            - 'l2.io'
52            - 'myexternalip.com'
53            - 'wgetip.com'
54            - 'whatismyip.akamai.com'
55            - 'wtfismyip.com'
56    filter_optional_brave:
57        Image|endswith: '\brave.exe'
58    filter_optional_chrome:
59        Image:
60            - 'C:\Program Files\Google\Chrome\Application\chrome.exe'
61            - 'C:\Program Files (x86)\Google\Chrome\Application\chrome.exe'
62    filter_optional_firefox:
63        Image:
64            - 'C:\Program Files\Mozilla Firefox\firefox.exe'
65            - 'C:\Program Files (x86)\Mozilla Firefox\firefox.exe'
66    filter_optional_ie:
67        Image:
68            - 'C:\Program Files (x86)\Internet Explorer\iexplore.exe'
69            - 'C:\Program Files\Internet Explorer\iexplore.exe'
70    filter_optional_maxthon:
71        Image|endswith: '\maxthon.exe'
72    filter_optional_edge_1:
73        - Image|startswith: 'C:\Program Files (x86)\Microsoft\EdgeWebView\Application\'
74        - Image|endswith: '\WindowsApps\MicrosoftEdge.exe'
75        - Image:
76            - 'C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe'
77            - 'C:\Program Files\Microsoft\Edge\Application\msedge.exe'
78    filter_optional_edge_2:
79        Image|startswith:
80            - 'C:\Program Files (x86)\Microsoft\EdgeCore\'
81            - 'C:\Program Files\Microsoft\EdgeCore\'
82        Image|endswith:
83            - '\msedge.exe'
84            - '\msedgewebview2.exe'
85    filter_optional_opera:
86        Image|endswith: '\opera.exe'
87    filter_optional_safari:
88        Image|endswith: '\safari.exe'
89    filter_optional_seamonkey:
90        Image|endswith: '\seamonkey.exe'
91    filter_optional_vivaldi:
92        Image|endswith: '\vivaldi.exe'
93    filter_optional_whale:
94        Image|endswith: '\whale.exe'
95    condition: selection and not 1 of filter_optional_*
96falsepositives:
97    - Legitimate use of the external websites for troubleshooting or network monitoring
98level: medium