Sigma rule: PUA - Nimgrab Execution

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-2a4fadcc2ff0, updated 2024-11-23T00:00:00.000Z.

Rule

Title
PUA - Nimgrab Execution
Status
test
Level
high
Author
frack113
Date
2022-08-28
Modified
2024-11-23
File
rules/windows/process_creation/proc_creation_win_pua_nimgrab.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the usage of nimgrab, a tool bundled with the Nim programming framework and used for downloading files.

Log source

product
windows
category
process_creation

Detection

selection_name:
    Image|endswith: '\nimgrab.exe'
selection_hashes:
    Hashes|contains:
        - MD5=2DD44C3C29D667F5C0EF5F9D7C7FFB8B
        - SHA256=F266609E91985F0FE3E31C5E8FAEEEC4FFA5E0322D8B6F15FE69F4C5165B9559
        - IMPHASH=C07FDDD21D123EA9B3A08EEF44AAAC45
condition: 1 of selection_*

False positives (as the rule lists them)

  • Legitimate use of Nim on a developer systems

Tags

  • attack.command-and-control
  • attack.t1105

MITRE ATT&CK ids this rule names

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_pua_nimgrab.yml

Sources and licences

  • SigmaHQ

    "PUA - Nimgrab Execution" by frack113 (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_pua_nimgrab.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: PUA - Nimgrab Execution",
entity page, dataset version ref-2a4fadcc2ff0, updated 2024-11-23T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/74a12f18-505c-4114-8d0b-8448dd5485c6 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 74a12f18-505c-4114-8d0b-8448dd5485c6, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.