Modify User Shell Folders Startup Value

Status: test
Severity: high
Log source: product windows, category registry_set
Author: frack113, Swachchhanda Shrawan Poudel (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detect modification of the User Shell Folders registry values for Startup or Common Startup which could indicate persistence attempts. Attackers may modify User Shell Folders registry keys to point to malicious executables or scripts that will be executed during startup. This technique is often used to maintain persistence on a compromised system by ensuring that the malicious payload is executed automatically.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1547.001` Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder
Privilege Escalation	`T1547.001` Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder

Event coverage

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

Rule body yaml

title: Modify User Shell Folders Startup Value
id: 9c226817-8dc9-46c2-a58d-66655aafd7dc
related:
    - id: 8f3ab69a-aa22-4943-aa58-e0a52fdf6818
      type: similar
status: test
description: |
    Detect modification of the User Shell Folders registry values for Startup or Common Startup which could indicate persistence attempts.
    Attackers may modify User Shell Folders registry keys to point to malicious executables or scripts that will be executed during startup.
    This technique is often used to maintain persistence on a compromised system by ensuring that the malicious payload is executed automatically.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/9e5b12c4912c07562aec7500447b11fa3e17e254/atomics/T1547.001/T1547.001.md
    - https://www.welivesecurity.com/en/eset-research/muddywater-snakes-riverbank/
author: frack113, Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2022-10-01
modified: 2026-01-05
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1547.001
logsource:
    product: windows
    category: registry_set
detection:
    selection:
        TargetObject|contains:
            - 'SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders'
            - 'SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders'
        TargetObject|endswith:
            - '\Common Startup'
            - '\Startup'
    filter_main_details_null:
        Details: null
    filter_main_programdata_startup:
        Details|contains:
            - 'C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup'
            - '%ProgramData%\Microsoft\Windows\Start Menu\Programs\Startup'
    filter_main_userprofile_startup_1:
        Details|contains:
            - '%USERPROFILE%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup'
            - '%%USERPROFILE%%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup'
    filter_main_userprofile_startup_2:
        Details|contains|all:
            - 'C:\Users\'
            - '\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup'
    # Apply more filters if new legitimate paths are identified
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high
regression_tests_path: regression_data/rules/windows/registry/registry_set/registry_set_susp_user_shell_folders/info.yml
simulation:
    - type: atomic-red-team
      name: Change Startup Folder - HKLM Modify User Shell Folders Common Startup Value
      technique: T1547.001
      atomic_guid: acfef903-7662-447e-a391-9c91c2f00f7b

Stages and Predicates

Stage 0: `condition`

selection and not 1 of filter_main_*

Stage 1: `selection`

selection:
    TargetObject|contains:
        - 'SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders'
        - 'SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders'
    TargetObject|endswith:
        - '\Common Startup'
        - '\Startup'

Stage 2: `not filter_main_*`

filter_main_details_null:
    Details: null
filter_main_programdata_startup:
    Details|contains:
        - 'C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup'
        - '%ProgramData%\Microsoft\Windows\Start Menu\Programs\Startup'
filter_main_userprofile_startup_1:
    Details|contains:
        - '%USERPROFILE%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup'
        - '%%USERPROFILE%%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup'
filter_main_userprofile_startup_2:
    Details|contains|all:
        - 'C:\Users\'
        - '\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup'

Exclusions

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

Field	Kind	Excluded values
`Details`	match	`C:\Users\`
`Details`	match	`\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup`
`Details`	is_null	(no value, null check)
`Details`	match	`%%USERPROFILE%%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup`
`Details`	match	`%ProgramData%\Microsoft\Windows\Start Menu\Programs\Startup`
`Details`	match	`%USERPROFILE%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup`
`Details`	match	`C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup`

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
`TargetObject`	ends_with	`\Common Startup` `\Startup`
`TargetObject`	match	`SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders` `SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders`

`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)

Modify User Shell Folders Startup Value

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection`

Stage 2: `not filter_main_*`

Exclusions

Indicators

Keyboard shortcuts

Search operators

Modify User Shell Folders Startup Value

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection

Stage 2: not filter_main_*

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection`

Stage 2: `not filter_main_*`