macOS Service Disruption Activity

Status: experimental
Severity: medium
Log source: product macos, service endpointsecurity
Author: Eric Brown - Nebulock, Inc.
Source: github.com/Nebulock-Inc/macos-coresigma

Detects execution of service control tools (launchctl, killall, pkill) with parameters targeting system services or multiple processes. May indicate service disruption for impact or denial of service attacks.

MITRE ATT&CK coverage

Tactic	Techniques
Impact	`T1489` Service Stop, `T1529` System Shutdown/Reboot

Rule body yaml

title: macOS Service Disruption Activity
id: e673e584-70d1-4b1e-9bdf-48f7eb0064d9
status: experimental
description: 'Detects execution of service control tools (launchctl, killall, pkill)
  with

  parameters targeting system services or multiple processes. May indicate service

  disruption for impact or denial of service attacks.

  '
author: Eric Brown - Nebulock, Inc.
date: 2025/10/31
modified: 2025/10/31
references:
- https://attack.mitre.org/techniques/T1489/
- https://attack.mitre.org/techniques/T1529/
logsource:
  product: macos
  service: endpointsecurity
detection:
  selection_event:
    esf.event_type: 9
    event.action: exec
  selection_launchctl:
    Image|endswith: /launchctl
    CommandLine|contains:
    - unload
    - remove
    - disable
    - stop
  selection_kill:
    Image|endswith:
    - killall
    - pkill
    CommandLine|contains:
    - '-9'
    - SIGKILL
    - -KILL
  selection_root:
    UserId: 0
  condition: selection_event and (selection_launchctl or selection_kill) and not selection_root
falsepositives:
- System administration and service management
- Software updates requiring service restarts
- Legitimate process termination
- Troubleshooting and maintenance activities
- Root user administrative actions
fields:
- Image
- CommandLine
- ProcessId
- ParentProcessId
- User
tags:
- attack.impact
- attack.t1489
- attack.t1529
level: medium

Stages and Predicates

Stage 0: `condition`

selection_event and (selection_launchctl or selection_kill) and not selection_root

Stage 1: `selection_event`

selection_event:
  esf.event_type: 9
  event.action: exec

Stage 2: `selection_launchctl`

selection_launchctl:
  Image|endswith: /launchctl
  CommandLine|contains:
  - unload
  - remove
  - disable
  - stop

Stage 3: `selection_kill`

selection_kill:
  Image|endswith:
  - killall
  - pkill
  CommandLine|contains:
  - '-9'
  - SIGKILL
  - -KILL

Stage 4: `not selection_root`

selection_root:
  UserId: 0

Exclusions

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

Field	Kind	Excluded values
`UserId`	eq	`0`

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	`-9` `-KILL` `SIGKILL` `disable` `remove` `stop` `unload`
`Image`	ends_with	`/launchctl` `killall` `pkill`
`esf.event_type`	eq	`9`
`event.action`	eq	`exec`

`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)

macOS Service Disruption Activity

MITRE ATT&CK coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_event`

Stage 2: `selection_launchctl`

Stage 3: `selection_kill`

Stage 4: `not selection_root`

Exclusions

Indicators

Keyboard shortcuts

Search operators

macOS Service Disruption Activity

MITRE ATT&CK coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_event

Stage 2: selection_launchctl

Stage 3: selection_kill

Stage 4: not selection_root

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection_event`

Stage 2: `selection_launchctl`

Stage 3: `selection_kill`

Stage 4: `not selection_root`