Sigma rule: Suspicious Explorer Process with Whitespace Padding - ClickFix/FileFix

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-571fc9c37533, updated 2025-11-26T00:00:00.000Z.

Rule

Title: Suspicious Explorer Process with Whitespace Padding - ClickFix/FileFix
Status: experimental
Level: high
Author: Swachchhanda Shrawan Poudel (Nextron Systems)
Date: 2025-11-04
Modified: 2025-11-26
File: rules/windows/process_creation/proc_creation_win_susp_clickfix_filefix_whitespace_padding.yml
Commit: ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects process creation with suspicious whitespace padding followed by a '#' character, which may indicate ClickFix or FileFix techniques used to conceal malicious commands from visual inspection.
ClickFix and FileFix are social engineering attack techniques where adversaries distribute phishing documents or malicious links that deceive users into opening the Windows Run dialog box or File Explorer search bar.
The victims are then instructed to paste commands from their clipboard, which contain extensive whitespace padding using various Unicode space characters to push the actual malicious command far to the right, effectively hiding it from immediate view.

Log source

product: windows
category: process_creation

Detection

selection_explorer:
    ParentImage|endswith: '\explorer.exe'
    CommandLine|contains: '#'
selection_space_variation:
    CommandLine|contains:
        - '            ' # En Quad (U+2000)
        - '            ' # Em Quad (U+2001)
        - '            ' # En Space (U+2002)
        - '            ' # Em Space (U+2003)
        - '            ' # Three-Per-Em Space (U+2004)
        - '            ' # Four-Per-Em Space (U+2005)
        - '            ' # Six-Per-Em Space (U+2006)
        - '            ' # Figure Space (U+2007)
        - '            ' # Punctuation Space (U+2008)
        - '            ' # Thin Space (U+2009)
        - '            ' # Hair Space (U+200A)
        - '            ' # No-Break Space (U+00A0)
        - '            ' # Normal space (0x20)
condition: all of selection_*

False positives (as the rule lists them)

Unknown

MITRE ATT&CK ids this rule names

Related rules

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_susp_clickfix_filefix_whitespace_padding.yml

Sources and licences

SigmaHQ
"Suspicious Explorer Process with Whitespace Padding - ClickFix/FileFix" by Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_susp_clickfix_filefix_whitespace_padding.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 Explorer Process with Whitespace Padding - ClickFix/FileFix",
entity page, dataset version ref-571fc9c37533, updated 2025-11-26T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/3ae9974a-eb09-4044-8e70-8980a50c12c8 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 3ae9974a-eb09-4044-8e70-8980a50c12c8, 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.