Detection rules › Sigma
PUA - NimScan Execution
Detects usage of NimScan, a portscanner utility. In early 2025, adversaries were observed using this utility to scan for open ports on remote hosts in a compromised environment. This rule identifies the execution of NimScan based on the process image name and specific hash values associated with different versions of the tool.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Discovery | T1046 Network Service Discovery |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 1 | Process creation |
Stages and Predicates
Stage 1: selection
or:
Hashes|contains: 'IMPHASH=0D1F896DC7642AD8384F9042F30279C2'
Hashes|contains: 'IMPHASH=41BB1C7571B3A724EB83A1D2B96DBB8C'
Hashes|contains: 'IMPHASH=B1B6ADACB172795480179EFD18A29549'
Image|endswith: '\NimScan.exe'
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 |
|---|---|---|
Hashes | match |
|
Image | ends_with |
|