Detection rules › Splunk

masscan Execution - Windows (Windows Event Log)

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

Masscan is a high-performance, open-source network scanning tool designed to scan large ranges of IP addresses for open ports, offering similar functionality to Nmap but with significantly faster scanning capabilities. Threat actors may use port and vulnerability scanning tools to identify running services and potential exploits on remote hosts and network devices. This use case detects masscan executions.

MITRE ATT&CK coverage

TacticTechniques
Discovery

References

Telemetry coverage

Rule body

id: '36445.64009'
title: masscan Execution - Windows
description: Masscan is a high-performance, open-source network scanning tool designed
  to scan large ranges of IP addresses for open ports, offering similar functionality
  to Nmap but with significantly faster scanning capabilities. Threat actors may use
  port and vulnerability scanning tools to identify running services and potential
  exploits on remote hosts and network devices. This use case detects masscan executions.
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
  "<EventID>4688<" OR Type=Process) (TERM(masscan) OR "masscan.exe") | regex process_name="(?i)masscan\.exe"
  | table _time, host, user, process, process_*, parent_* | bin span=1s | stats values(*)
  as * by _time, host '
techniques:
- discovery:network service discovery
technique_id: 
- T1046
data_category:
- Windows event logs
references:
- https://github.com/robertdavidgraham/masscan/tree/master
- https://attack.mitre.org/techniques/T1046/
- https://cybersecurity.att.com/blogs/labs-research/teamtnt-with-new-campaign-aka-chimaera
- https://unit42.paloaltonetworks.com/hildegard-malware-teamtnt/
- https://www.kali.org/tools/masscan/

Stages and Predicates

Stage 1: search

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

Stage 2: regex

| regex process_name="(?i)masscan\.exe"

Stage 3: table

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

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
EventCodeeq
  • 4688 corpus 317 (splunk 283, kusto 33, elastic 1)
field:"EventID" kind:eq value:"4688"
process_nameregex_match
  • "(?i)masscan.exe" corpus 2 (splunk 2)
field:"process_name" kind:regex_match

Search terms

These SPL tokens match against raw event text.

StageTerm
1"<EventID>4688<"
1masscan
1"masscan.exe"