FileFix - Command Evidence in TypedPaths

Status: experimental
Severity: high
Log source: product windows, category registry_set
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

Event coverage

Provider	Event	Title
Sysmon	Event ID 13	RegistryEvent (Value Set)

Rule body yaml

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

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`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 2 (sigma 2) `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 10 (sigma 9, 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)
`TargetObject`	ends_with	`\Software\Microsoft\Windows\CurrentVersion\Explorer\TypedPaths\url1` corpus 2 (sigma 2)

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

FileFix - Command Evidence in TypedPaths

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_base`

Stage 2: `selection_cmd`

Indicators

Keyboard shortcuts

Search operators

FileFix - Command Evidence in TypedPaths

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_base

Stage 2: selection_cmd

Indicators

Stage 0: `condition`

Stage 1: `selection_base`

Stage 2: `selection_cmd`