FileFix - Command Evidence in TypedPaths

Status: experimental
Severity: high
Log source: category registry_set, product windows
Author: Alfie Champion (delivr.to), Swachchhanda Shrawan Poudel (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects commonly-used chained commands and strings in the most recent 'url' value of the 'TypedPaths' key, which could be indicative of a user being targeted by the FileFix technique.

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1204.004` User Execution: Malicious Copy and Paste

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 13: RegistryEvent (Value Set)

Rule body

title: FileFix - Command Evidence in TypedPaths
id: 4fee3d51-8069-4a4c-a0f7-924fcaff2c70
related:
    - id: 4be03877-d5b6-4520-85c9-a5911c0a656c
      type: similar
status: experimental
description: |
    Detects commonly-used chained commands and strings in the most recent 'url' value of the 'TypedPaths' key, which could be indicative of a user being targeted by the FileFix technique.
references:
    - https://x.com/russianpanda9xx/status/1940831134759506029
    - https://mrd0x.com/filefix-clickfix-alternative/
    - https://www.scpx.com.au/2025/11/16/decades-old-finger-protocol-abused-in-clickfix-malware-attacks/
author: Alfie Champion (delivr.to), Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-07-05
modified: 2025-11-19
tags:
    - attack.execution
    - attack.t1204.004
logsource:
    category: registry_set
    product: windows
detection:
    selection_base:
        TargetObject|endswith: '\Software\Microsoft\Windows\CurrentVersion\Explorer\TypedPaths\url1'
        Details|contains|all:
            - '#'
            - 'http'
    selection_cmd:
        - Details|contains:
              # Add more suspicious keywords
              - 'account'
              - 'anti-bot'
              - 'botcheck'
              - 'captcha'
              - 'challenge'
              - 'confirmation'
              - 'fraud'
              - 'human'
              - 'identification'
              - 'identificator'
              - 'identity'
              - 'robot'
              - 'validation'
              - 'verification'
              - 'verify'
        - Details|contains:
              - '%comspec%'
              - 'bitsadmin'
              - 'certutil'
              - 'cmd'
              - 'cscript'
              - 'curl'
              - 'finger'
              - 'mshta'
              - 'powershell'
              - 'pwsh'
              - 'regsvr32'
              - 'rundll32'
              - 'schtasks'
              - 'wget'
              - 'wscript'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_base`

selection_base:
    TargetObject|endswith: '\Software\Microsoft\Windows\CurrentVersion\Explorer\TypedPaths\url1'
    Details|contains|all:
        - '#'
        - 'http'

Stage 2: `selection_cmd`

selection_cmd:
    - Details|contains:
          - 'account'
          - 'anti-bot'
          - 'botcheck'
          - 'captcha'
          - 'challenge'
          - 'confirmation'
          - 'fraud'
          - 'human'
          - 'identification'
          - 'identificator'
          - 'identity'
          - 'robot'
          - 'validation'
          - 'verification'
          - 'verify'
    - Details|contains:
          - '%comspec%'
          - 'bitsadmin'
          - 'certutil'
          - 'cmd'
          - 'cscript'
          - 'curl'
          - 'finger'
          - 'mshta'
          - 'powershell'
          - 'pwsh'
          - 'regsvr32'
          - 'rundll32'
          - 'schtasks'
          - 'wget'
          - 'wscript'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Details`	match	`#` corpus 3 (sigma 3) `%comspec%` corpus 3 (sigma 3) `account` corpus 2 (sigma 2) `anti-bot` corpus 2 (sigma 2) `bitsadmin` corpus 2 (sigma 2) `botcheck` corpus 2 (sigma 2) `captcha` corpus 2 (sigma 2) `certutil` corpus 2 (sigma 2) `challenge` corpus 2 (sigma 2) `cmd` corpus 3 (sigma 3) `confirmation` corpus 2 (sigma 2) `cscript` corpus 4 (sigma 4) `curl` corpus 2 (sigma 2) `finger` corpus 2 (sigma 2) `fraud` corpus 2 (sigma 2) `http` corpus 3 (sigma 2, elastic 1) `human` corpus 2 (sigma 2) `identification` corpus 2 (sigma 2) `identificator` corpus 2 (sigma 2) `identity` corpus 2 (sigma 2) `mshta` corpus 5 (sigma 4, splunk 1) `powershell` corpus 11 (sigma 9, elastic 1, chronicle 1) `pwsh` corpus 5 (sigma 5) `regsvr32` corpus 3 (sigma 3) `robot` corpus 2 (sigma 2) `rundll32` corpus 4 (sigma 4) `schtasks` corpus 2 (sigma 2) `validation` corpus 2 (sigma 2) `verification` corpus 2 (sigma 2) `verify` corpus 2 (sigma 2) `wget` corpus 2 (sigma 2) `wscript` corpus 4 (sigma 4)	`field:"Details" kind:match`
`TargetObject`	ends_with	`\Software\Microsoft\Windows\CurrentVersion\Explorer\TypedPaths\url1` corpus 2 (sigma 2)	`field:"TargetObject" kind:ends_with value:"\Software\Microsoft\Windows\CurrentVersion\Explorer\TypedPaths\url1"`