Windows NirSoft Tool Bundle File Created
The following analytic detects the creation of files associated with the NirSoft tool bundles on Windows endpoints. NirSoft is a well-known provider of free, portable utilities that can be used for various system and…
Description
The following analytic detects the creation of files associated with the NirSoft tool bundles on Windows endpoints. NirSoft is a well-known provider of free, portable utilities that can be used for various system and network tasks. However, threat actors often leverage these tools for malicious purposes, such as credential harvesting, network reconnaissance, and data exfiltration. The detection focuses on the creation of specific NirSoft tool bundle files, which may indicate that an attacker is preparing to use these utilities on a compromised system. Security teams should investigate any instances of these files being created, especially if they are found in unexpected locations or on systems that should not be using such tools.
Detection logic
Detection requirements
- Platform
- PRE
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- sysmon_eventid_11
Known benign triggers
- Administrators or users may download NirSoft tools for legitimate purposes, such as system maintenance or troubleshooting. These instances should be reviewed to determine if the activity is authorized.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| asec.ahnlab.com/en/48940/ | Only this detection cites it |
| thedfirreport.com/2020/04/04/gogoogle-ransomware/ | 2 |
| www.trendmicro.com/en_gb/research/23/c/emotet-returns-now-adopts-binary-padding-for-evasion.html | Only this detection cites it |
| www.welivesecurity.com/2022/06/16/how-emotet-is-changing-tactics-microsoft-tightening-office-macro-security/ | Only this detection cites it |
From the source
- At source
- Open at source
- Upstream identifier
- a2c8e8f8-18d6-4ad4-acf4-f58903bebe41
- Tagged by the source as
- Data DestructionUnusual ProcessesWhisperGateEndpointendpointSplunk CloudSplunk EnterpriseSplunk Enterprise Securityendpoint
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Published
- Oct 14, 2026
- Version
- 2