Detection rules › Splunk

Nslookup Execution (Windows Event Log)

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

nslookup (from name server lookup) is a network administration command-line tool for querying the Domain Name System (DNS) to obtain domain name or IP address mapping, or other DNS records. Adversaries can use nslookup for various attack methods

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

id: '6172.6717'
title: Nslookup Execution
description: 'nslookup (from name server lookup) is a network administration command-line
  tool for querying the Domain Name System (DNS) to obtain domain name or IP address
  mapping, or other DNS records. Adversaries can use nslookup for various attack methods.
  Living Off the Land Binary and Scripts (LOLBAS) (LOLBIN) Threat Actor Association:
  FIN7'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
  "<EventID>4688<" OR Type=Process) (TERM(nslookup) OR "nslookup.exe") | table _time,
  host, user, signature_id, process, process_*, parent_process_* | bin span=1s | stats
  values(*) as * by _time, host '
techniques:
- defense-evasion:system binary proxy execution
- discovery:system network configuration discovery
technique_id: 
- T1218
- T1016
data_category:
- Windows event logs
references:
- https://isc.sans.edu/forums/diary/Exfiltrating+data+from+very+isolated+environments/23645/
- https://www.securityfocus.com/images/guestfeature/xinetica/How%20attackers%20exploit%20information%20for%20their%20own%20purposes.htm

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR "<EventID>4688<" OR Type=Process) (TERM(nslookup) OR "nslookup.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
1nslookup
1"nslookup.exe"