Sigma rule: Suspicious Calculator Usage

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-5ebd321d452a, updated 2023-11-09T00:00:00.000Z.

Rule

Title
Suspicious Calculator Usage
Status
test
Level
high
Author
Florian Roth (Nextron Systems)
Date
2019-02-09
Modified
2023-11-09
File
rules/windows/process_creation/proc_creation_win_calc_uncommon_exec.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects suspicious use of 'calc.exe' with command line parameters or in a suspicious directory, which is likely caused by some PoC or detection evasion.

Log source

product
windows
category
process_creation

Detection

selection_1:
    CommandLine|contains: '\calc.exe '
selection_2:
    Image|endswith: '\calc.exe'
filter_main_known_locations:
    Image|contains:
        - ':\Windows\System32\'
        - ':\Windows\SysWOW64\'
        - ':\Windows\WinSxS\'
condition: selection_1 or ( selection_2 and not filter_main_known_locations )

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.stealth
  • attack.t1036

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_calc_uncommon_exec.yml

Sources and licences

  • SigmaHQ

    "Suspicious Calculator Usage" by Florian Roth (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_calc_uncommon_exec.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: Suspicious Calculator Usage",
entity page, dataset version ref-5ebd321d452a, updated 2023-11-09T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/737e618a-a410-49b5-bec3-9e55ff7fbc15 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 737e618a-a410-49b5-bec3-9e55ff7fbc15, 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.