Linux System Network Discovery

Original Source: [splunk source]
Name:Linux System Network Discovery
id:535cb214-8b47-11ec-a2c7-acde48001122
version:10
date:2026-04-15
author:Teoderick Contreras, Splunk
status:production
type:Anomaly
Description:The following analytic identifies potential enumeration of local network configuration on Linux systems. It detects this activity by monitoring processes such as "arp," "ifconfig," "ip," "netstat," "firewall-cmd," "ufw," "iptables," "ss," and "route" within a 30-minute window. This behavior is significant as it often indicates reconnaissance efforts by adversaries to gather network information for subsequent attacks. If confirmed malicious, this activity could enable attackers to map the network, identify vulnerabilities, and plan further exploitation or lateral movement within the environment.
Data_source:
  • -Sysmon for Linux EventID 1
  • -Osquery Results
search:| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime
values(Processes.action) as action
values(Processes.original_file_name) as original_file_name
values(Processes.parent_process_exec) as parent_process_exec
values(Processes.parent_process_guid) as parent_process_guid
values(Processes.parent_process_id) as parent_process_id
values(Processes.parent_process_name) as parent_process_name
values(Processes.parent_process_path) as parent_process_path
values(Processes.parent_process) as parent_process
values(Processes.process_exec) as process_exec
values(Processes.process_guid) as process_guid
values(Processes.process_hash) as process_hash
values(Processes.process_id) as process_id
values(Processes.process_integrity_level) as process_integrity_level
values(Processes.process_name) as process_name
values(Processes.process_path) as process_path
values(Processes.process) as process
values(Processes.user_id) as user_id
values(Processes.vendor_product) as vendor_product
dc(Processes.process_name) as process_name_count
FROM datamodel=Endpoint.Processes WHERE

Processes.process_name IN (
"arp",
"firewall-cmd",
"ifconfig",
"ip",
"iptables",
"netstat",
"route",
"ss",
"ufw"
)

BY _time span=30m Processes.dest Processes.user

| where process_name_count>=4

| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `linux_system_network_discovery_filter`


how_to_implement:The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives:Administrator or network operator can execute this command. Please update the filter macros to remove false positives.
References:
  -https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1016/T1016.md
drilldown_searches:
name:'View the detection results for - "$dest$"'
search:'%original_detection_search% | search dest = "$dest$"'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
name:'View risk events for the last 7 days for - "$dest$"'
search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
tags:
  analytic_story:
    - 'Data Destruction'
    - 'Network Discovery'
    - 'Industroyer2'
    - 'VoidLink Cloud-Native Linux Malware'
  asset_type:Endpoint
  mitre_attack_id:
    - 'T1016'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1016/atomic_red_team/linux_net_discovery/sysmon_linux.log
  source: Syslog:Linux-Sysmon/Operational
  sourcetype: sysmon:linux
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1016/atomic_red_team/macos_net_discovery/macos_network_discovery.log
  sourcetype: osquery:results
  source: osquery
manual_test:None