Sigma rule: Small Sieve Malware File Indicator Creation

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-a9255632b9dd, updated 2023-05-19T00:00:00.000Z.

Rule

Title
Small Sieve Malware File Indicator Creation
Status
test
Level
high
Author
Nasreddine Bencherchali (Nextron Systems), X__Junior (Nextron Systems)
Date
2023-05-19
File
rules-emerging-threats/2021/Malware/Small-Sieve/file_event_win_malware_small_sieve_evasion_typo.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects filename indicators that contain a specific typo seen used by the Small Sieve malware.

Log source

product
windows
category
file_event

Detection

selection_typo_path:
    TargetFilename|contains|all:
        - ':\Users\'
        - '\AppData\'
    TargetFilename|contains:
        - '\Roaming\'
        - '\Local\'
selection_typo_keyword:
    TargetFilename|contains: 'Microsift'
selection_ioc:
    TargetFilename|endswith: '\AppData\Local\MicrosoftWindowsOutlookDataPlus.txt'
condition: all of selection_typo_* or selection_ioc

False positives (as the rule lists them)

  • Unlikely

Tags

  • attack.stealth
  • attack.t1036.005
  • detection.emerging-threats

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-emerging-threats/2021/Malware/Small-Sieve/file_event_win_malware_small_sieve_evasion_typo.yml

Sources and licences

  • SigmaHQ

    "Small Sieve Malware File Indicator Creation" by Nasreddine Bencherchali (Nextron Systems), X__Junior (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Malware/Small-Sieve/file_event_win_malware_small_sieve_evasion_typo.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: Small Sieve Malware File Indicator Creation",
entity page, dataset version ref-a9255632b9dd, updated 2023-05-19T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/39466c42-c189-476a-989f-8cdb135c163a (accessed 2026-11-03).
Underlying source: SigmaHQ rule 39466c42-c189-476a-989f-8cdb135c163a, 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.