Detection: Cisco NVM - Suspicious Network Connection to IP Lookup Service API

Updated Date: 2025-07-04 ID: 568cb83e-d79e-4a23-85ec-6e1f6c30cb2f Author: Nasreddine Bencherchali, Splunk, Janantha Marasinghe Type: Anomaly Product: Splunk Enterprise Security

Description

This analytic identifies non-browser processes reaching out to public IP lookup or geolocation services, such as ipinfo.io, icanhazip.com, ip-api.com, and others. These domains are commonly used by legitimate tools, but their usage outside of browsers may indicate network reconnaissance, virtual machine detection, or staging by malware. This activity is observed in post-exploitation frameworks, stealer malware, and advanced threat actor campaigns. The detection relies on Cisco Network Visibility Module (NVM) telemetry and excludes known browser processes to reduce noise.

Search

 1`cisco_network_visibility_module_flowdata`
 2dest_hostname IN (
 3        "*api.2ip.ua*", "*api.bigdatacloud.net*", "*api.ipify.org*", "*whatismyipaddress.com*",
 4        "*canireachthe.net*", "*checkip.amazonaws.com*", "*checkip.dyndns.org*", "*curlmyip.com*",
 5        "*db-ip.com*", "*edns.ip-api.com*", "*eth0.me*", "*freegeoip.app*", "*geoipy.com*", "*getip.pro*",
 6        "*icanhazip.com*", "*ident.me*", "*ifconfig.io*", "*ifconfig.me*", "*ip-api.com*", "*ip.360.cn*",
 7        "*ip.anysrc.net*", "*ip.taobao.com*", "*ip.tyk.nu*", "*ipaddressworld.com*", "*ipapi.co*",
 8        "*ipconfig.io*", "*ipecho.net*", "*ipinfo.io*", "*ipip.net*", "*iplocation.net*", 
 9        "*ipof.in*", "*ipv6-test.com*", "*ipwho.is*", "*trackip.net*", "*inet-ip.info*",
10        "*jsonip.com*", "*myexternalip.com*", "*seeip.org*",  "*wgetip.com*", 
11        "*whatismyip.akamai.com*", "*whois.pconline.com.cn*", "*wtfismyip.com*", "*ip.cn"
12        )
13NOT process_name IN (
14        "brave.exe", "chrome.exe", "firefox.exe", "iexplore.exe", "maxthon.exe",
15        "MicrosoftEdge.exe", "msedge.exe", "msedgewebview2.exe", "opera.exe", "safari.exe",
16        "seamonkey.exe", "vivaldi.exe", "whale.exe"
17  )
18
19| stats count min(_time) as firstTime max(_time) as lastTime
20        values(parent_process_arguments) as parent_process_arguments
21        values(process_arguments) as process_arguments
22        values(parent_process_hash) as parent_process_hash
23        values(process_hash) as process_hash
24        values(module_name_list) as module_name_list
25        values(module_hash_list) as module_hash_list
26        values(dest_port) as dest_port
27        values(aliul) as additional_logged_in_users_list
28        values(dest_hostname) as dest_hostname
29        by src dest parent_process_path parent_process_integrity_level process_path process_name process_integrity_level process_id transport
30
31| `security_content_ctime(firstTime)`
32
33| `security_content_ctime(lastTime)`
34
35| table
36  parent_process_integrity_level parent_process_path parent_process_arguments parent_process_hash
37  process_integrity_level process_path process_name process_arguments process_hash process_id
38  additional_logged_in_users_list module_name_list module_hash_list
39  src dest_hostname dest dest_port transport firstTime lastTime
40
41| `cisco_nvm___suspicious_network_connection_to_ip_lookup_service_api_filter`

Data Source

No data sources specified for this detection.

Macros Used

Name	Value
cisco_network_visibility_module_flowdata	`sourcetype="cisco:nvm:flowdata"`
cisco_nvm___suspicious_network_connection_to_ip_lookup_service_api_filter	`search *`

cisco_nvm___suspicious_network_connection_to_ip_lookup_service_api_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1590.005	IP Addresses	Reconnaissance
T1016	System Network Configuration Discovery	Discovery

Exploitation

Reconnaissance

DE.AE

CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Risk Event	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

This search requires Network Visibility Module logs, which includes the flow data sourcetype. This search uses an input macro named cisco_network_visibility_module_flowdata. We strongly recommend that you specify your environment-specific configurations (index, source, sourcetype, etc.) for Cisco Network Visibility Module logs. Replace the macro definition with configurations for your Splunk environment. The search also uses a post-filter macro designed to filter out known false positives. The logs are to be ingested using the Splunk Add-on for Cisco Endpoint Security Analytics (CESA) (https://splunkbase.splunk.com/app/4221).

Known False Positives

Internal scripts or agents performing network checks may query IP geolocation services. Tune by excluding known tools or adding internal allowlists for destination domains or process names and commandlines.

Associated Analytic Story

Cisco Network Visibility Module Analytics

Risk Based Analytics (RBA)

Risk Message:

The host $src$ made a network request to IP lookup service $dest_hostname$ using suspicious process $process_path$

Risk Object	Risk Object Type	Risk Score	Threat Objects
src	system	40	process_name

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`not_applicable`	`cisco:nvm:flowdata`
Integration	✅ Passing	Dataset	`not_applicable`	`cisco:nvm:flowdata`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 1