Detection rules › Splunk
masscan Execution - Windows (Sysmon)
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
| Tactic | Techniques |
|---|---|
| Discovery |
References
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
id: '36445.64010'
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_sysmon` (TERM(EventCode=1) OR "<EventID>1<")
(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 Sysmon
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_sysmon` (TERM(EventCode=1) OR "<EventID>1<") (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.
| Field | Kind | Values | Search |
|---|---|---|---|
EventCode | eq |
| field:"EventID" kind:eq value:"1" |
process_name | regex_match |
| field:"process_name" kind:regex_match |
Search terms
These SPL tokens match against raw event text.
| Stage | Term |
|---|---|
| 1 | "<EventID>1<" |
| 1 | masscan |
| 1 | "masscan.exe" |