Detection rules › Splunk

NMAP Execution

Group by
_time, host
Source
github.com/anvilogic-forge/armory

Adversaries may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for Lateral Movement from the current system. This use case looks for executions of nmap that have been passed an IPv4 Address

MITRE ATT&CK coverage

TacticTechniques
Discovery

References

Telemetry coverage

Rule body

id: '6127.6609'
title: NMAP Execution
description: 'Adversaries may attempt to get a listing of other systems by IP address,
  hostname, or other logical identifier on a network that may be used for Lateral
  Movement from the current system. This use case looks for executions of nmap that
  have been passed an IPv4 Address. -- Threat Actor Association: Alloy Taurus/Gallium'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_unix` (TERM(nmap) type IN("proctitle",
  "execve", "USER_CMD")) | regex process="(?i)nmap\s.+?(\d{1,3}\.){3}\d{1,3}" | table
  _time, host, user, process, process_*, type | bin span=1s | stats values(*) as *
  by _time, host '
techniques:
- discovery:remote system discovery
technique_id: 
- T1018
data_category:
- Process command-line parameters
references:
- https://www.group-ib.com/resources/threat-research/silence_moving-into-the-darkside.pdf

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_unix` (TERM(nmap) type IN("proctitle", "execve", "USER_CMD"))

Stage 2: regex

| regex process="(?i)nmap\s.+?(\d{1,3}\.){3}\d{1,3}"

Stage 3: table

| table _time, host, user, process, process_*, type

Stage 4: bucket

| bin span=1s

Stage 5: stats

| stats values(*) as * by _time, host

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
processregex_match
  • "(?i)nmap\s.+?(\d{1,3}.){3}\d{1,3}"
field:"CommandLine" kind:regex_match
typein
  • "USER_CMD"
  • "execve"
  • "proctitle"
field:"type" kind:in

Search terms

These SPL tokens match against raw event text.

StageTerm
1nmap