Detection rules › Splunk

NMAP Execution (Windows Event Log)

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
DiscoveryT1018 Remote System Discovery

References

Event coverage

Rule body yaml

id: '6127.6610'
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_winevent` (TERM(EventCode=4688) OR
  "<EventID>4688<" OR Type=Process) (TERM(nmap) OR "nmap.exe") | table _time, host,
  user, signature_id, process, process_*, parent_process_* | bin span=1s | stats values(*)
  as * by _time, host '
techniques:
- discovery:remote system discovery
technique_id: 
- T1018
data_category:
- Windows event logs
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_winevent` (TERM(EventCode=4688) OR "<EventID>4688<" OR Type=Process) (TERM(nmap) OR "nmap.exe")

Stage 2: table

| table _time, host, user, signature_id, process, process_*, parent_process_*

Stage 3: bucket

| bin span=1s

Stage 4: stats

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

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
EventCodeeq
  • 4688 corpus 313 (splunk 283, kusto 30)

Search terms

Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.

StageTerm
1TERM
1"<EventID>4688<"
1TERM
1nmap
1"nmap.exe"