Detection rules › Splunk
Advanced Port Scanner Execution (Windows Event Log)
Advanced Port Scanner is a free network scanner that allows users to quickly find open ports on network computers and retrieve versions of programs running on the ports it detects. Threat actors using Rhysida ransomware have been reported to use Advanced Port Scanner during reconnaissance activities.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Discovery | T1046 Network Service Discovery |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
id: '25757.47714'
title: Advanced Port Scanner Execution
description: Advanced Port Scanner is a free network scanner that allows users to
quickly find open ports on network computers and retrieve versions of programs running
on the ports it detects. Threat actors using Rhysida ransomware have been reported
to use Advanced Port Scanner during reconnaissance activities.
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
"<EventID>4688<" OR Type=Process) "advanced_port_scanner.exe" | where match(process_name,
"(?i)advanced_port_scanner\.exe") | table _time, host, user, process, process_*,
parent_process_* | bin span=1s | stats values(*) as * by _time, host '
techniques:
- discovery:network service discovery
technique_id:
- T1046
data_category:
- Windows event logs
references:
- https://www.fortinet.com/content/dam/fortinet/assets/threat-reports/rhysida-ransomware-intrusion.pdf?utm_source=blog&utm_medium=blog&utm_campaign=rhysida-ransomware
- https://www.advanced-port-scanner.com/
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR "<EventID>4688<" OR Type=Process) "advanced_port_scanner.exe"
Stage 2: where
| where match(process_name, "(?i)advanced_port_scanner\.exe")
Stage 3: table
| table _time, host, user, process, process_*, parent_process_*
Stage 4: bucket
| bin span=1s
Stage 5: 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.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
process_name | match |
|
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.
| Stage | Term |
|---|---|
| 1 | TERM |
| 1 | "<EventID>4688<" |
| 1 | "advanced_port_scanner.exe" |