Service permissions hijacked for privileges abuse (service)

Status: experimental
Severity: high
Log source: product windows, category process_creation
Author: mdecrevoisier
Source: github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker modify the permissions of a service in order to abuse its privileges

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1574.010` Hijack Execution Flow: Services File Permissions Weakness
Persistence	`T1543.003` Create or Modify System Process: Windows Service
Stealth	`T1574.010` Hijack Execution Flow: Services File Permissions Weakness

Event coverage

Provider	Event	Title
Sysmon	Event ID 1	Process creation
Security-Auditing	Event ID 4688	A new process has been created.

Rule body yaml

title: Service permissions hijacked for privileges abuse (service)
description: Detects scenarios where an attacker modify the permissions of a service in order to abuse its privileges
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0003-Persistence/T1543.003-Create%20or%20Modify%20System%20Process-Windows%20Service
- http://woshub.com/set-permissions-on-windows-service/
- https://www.winhelponline.com/blog/view-edit-service-permissions-windows/
- https://decoder.cloud/2019/02/07/demystifying-windows-service-permissions-configuration/
- https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.management/set-service?view=powershell-7.1
- https://medium.com/r3d-buck3t/abuse-service-registry-acls-windows-privesc-f88079140509
- https://github.com/rohnedwards/PowerShellAccessControl
tags:
- attack.persistence
- attack.t1543.003
- attack.t1574.010
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  category: process_creation
detection:
  selection_sdset: # full command (native commmand): "sc sdset XblGameSave "D:(A;;CCLCSWRPWPDTLOCRRC;;;SY)"
    NewProcessName|endswith: '\sc.exe'
    CommandLine|contains: sdset

  selection_subinACL: # full command (3rd party tool): subinacl.exe /service Spooler /grant=contoso\tuser=PTO
    CommandLine|contains|all:
      #- subinacl # not considered as executable name can be changed
      - 'service'
      - 'grant='

  selection_setACL: # full command (3rd party tool): SetACL.exe -on "schedule" -ot srv -actn list
    CommandLine|contains|all:
      #- setacl # not considered as executable name can be changed
      - 'on'   # object name
      - 'srv'  # object type
      - 'actn' # action

  condition: selection_sdset OR selection_subinACL OR selection_setACL
falsepositives:
- administrator reconfiguring service
level: high

Stages and Predicates

Stage 0: `condition`

selection_sdset OR selection_subinACL OR selection_setACL

Stage 1: `selection_sdset`

selection_sdset:
  NewProcessName|endswith: '\sc.exe'
  CommandLine|contains: sdset

Stage 2: `selection_subinACL`

selection_subinACL:
  CommandLine|contains|all:
    - 'service'
    - 'grant='

Stage 3: `selection_setACL`

selection_setACL:
  CommandLine|contains|all:
    - 'on'
    - 'srv'
    - 'actn'

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
`CommandLine`	match	`actn` `grant=` `on` `sdset` corpus 5 (sigma 5) `service` corpus 5 (sigma 4, splunk 1) `srv`
`NewProcessName`	ends_with	`\sc.exe` corpus 30 (sigma 30)

`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)

Service permissions hijacked for privileges abuse (service)

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_sdset`

Stage 2: `selection_subinACL`

Stage 3: `selection_setACL`

Indicators

Keyboard shortcuts

Search operators

Service permissions hijacked for privileges abuse (service)

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_sdset

Stage 2: selection_subinACL

Stage 3: selection_setACL

Indicators

Stage 0: `condition`

Stage 1: `selection_sdset`

Stage 2: `selection_subinACL`

Stage 3: `selection_setACL`