Use Short Name Path in Image

Status: test
Severity: medium
Log source: product windows, category process_creation
Author: frack113, Nasreddine Bencherchali
Source: github.com/SigmaHQ/sigma

Detect use of the Windows 8.3 short name. Which could be used as a method to avoid Image detection

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1564.004` Hide Artifacts: NTFS File Attributes

Event coverage

Provider	Event	Title
Sysmon	Event ID 1	Process creation

Rule body yaml

title: Use Short Name Path in Image
id: a96970af-f126-420d-90e1-d37bf25e50e1
related:
    - id: 349d891d-fef0-4fe4-bc53-eee623a15969
      type: similar
status: test
description: Detect use of the Windows 8.3 short name. Which could be used as a method to avoid Image detection
references:
    - https://www.acunetix.com/blog/articles/windows-short-8-3-filenames-web-security-problem/
    - https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc959352(v=technet.10)
    - https://twitter.com/frack113/status/1555830623633375232
author: frack113, Nasreddine Bencherchali
date: 2022-08-07
modified: 2025-10-20
tags:
    - attack.stealth
    - attack.t1564.004
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|contains:
            - '~1\'
            - '~2\'
    filter_main_system_process:
        ParentImage:
            - 'C:\Windows\System32\Dism.exe'
            - 'C:\Windows\System32\cleanmgr.exe'  # Spawns DismHost.exe with a shortened username (if too long)
    filter_main_installers:
        - Image|contains|all:
              - '\AppData\'
              - '\Temp\'
        - Image|endswith:
              - '~1\unzip.exe'
              - '~1\7zG.exe'
    filter_optional_webex:
        ParentImage|endswith: '\WebEx\WebexHost.exe' # Spawns a shortened version of the CLI and Image processes
    filter_optional_thor:
        ParentImage|endswith: '\thor\thor64.exe'
    filter_optional_installshield:
        - Product: 'InstallShield (R)'
        - Description: 'InstallShield (R) Setup Engine'
        - Company: 'InstallShield Software Corporation'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Applications could use this notation occasionally which might generate some false positives. In that case Investigate the parent and child process.
level: medium

Stages and Predicates

Stage 0: `condition`

selection and not 1 of filter_main_* and not 1 of filter_optional_*

Stage 1: `selection`

selection:
    Image|contains:
        - '~1\'
        - '~2\'

Stage 2: `not filter_main_*`

filter_main_system_process:
    ParentImage:
        - 'C:\Windows\System32\Dism.exe'
        - 'C:\Windows\System32\cleanmgr.exe'
filter_main_installers:
    - Image|contains|all:
          - '\AppData\'
          - '\Temp\'
    - Image|endswith:
          - '~1\unzip.exe'
          - '~1\7zG.exe'

Stage 3: `not filter_optional_*`

filter_optional_webex:
    ParentImage|endswith: '\WebEx\WebexHost.exe'
filter_optional_thor:
    ParentImage|endswith: '\thor\thor64.exe'
filter_optional_installshield:
    - Product: 'InstallShield (R)'
    - Description: 'InstallShield (R) Setup Engine'
    - Company: 'InstallShield Software Corporation'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`Image`	match	`\AppData\`
`Image`	match	`\Temp\`
`Image`	ends_with	`~1\7zG.exe`
`Image`	ends_with	`~1\unzip.exe`
`ParentImage`	eq	`C:\Windows\System32\Dism.exe`
`ParentImage`	eq	`C:\Windows\System32\cleanmgr.exe`
`Company`	eq	`InstallShield Software Corporation`
`Description`	eq	`InstallShield (R) Setup Engine`
`ParentImage`	ends_with	`\WebEx\WebexHost.exe`
`ParentImage`	ends_with	`\thor\thor64.exe`
`Product`	eq	`InstallShield (R)`

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
`Image`	match	`~1\` `~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)

Use Short Name Path in Image

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection`

Stage 2: `not filter_main_*`

Stage 3: `not filter_optional_*`

Exclusions

Indicators

Keyboard shortcuts

Search operators

Use Short Name Path in Image

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection

Stage 2: not filter_main_*

Stage 3: not filter_optional_*

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection`

Stage 2: `not filter_main_*`

Stage 3: `not filter_optional_*`