Circle CI Disable Security Job

Status: production
Severity: low
Group by: branch, commit_message, url, user, workflow_id, workflow_name
Author: Patrick Bareiss, Splunk
Source: github.com/splunk/security_content

The following analytic detects the disabling of security jobs in CircleCI pipelines. It leverages CircleCI log data, renaming and extracting fields such as job names, workflow IDs, user information, commit messages, URLs, and branches. The detection identifies mandatory jobs for each workflow and checks if they were executed. This activity is significant because disabling security jobs can allow malicious code to bypass security checks, leading to potential data breaches, system downtime, and reputational damage. If confirmed malicious, this could result in unauthorized code execution and compromised pipeline integrity.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1554` Compromise Host Software Binary

Rule body splunk

name: Circle CI Disable Security Job
id: 4a2fdd41-c578-4cd4-9ef7-980e352517f2
version: 10
creation_date: '2021-09-02'
modification_date: '2026-05-13'
author: Patrick Bareiss, Splunk
status: production
type: Anomaly
description: The following analytic detects the disabling of security jobs in CircleCI pipelines. It leverages CircleCI log data, renaming and extracting fields such as job names, workflow IDs, user information, commit messages, URLs, and branches. The detection identifies mandatory jobs for each workflow and checks if they were executed. This activity is significant because disabling security jobs can allow malicious code to bypass security checks, leading to potential data breaches, system downtime, and reputational damage. If confirmed malicious, this could result in unauthorized code execution and compromised pipeline integrity.
data_source:
    - CircleCI
search: |-
    `circleci`
      | rename vcs.committer_name as user vcs.subject as commit_message vcs.url as url workflows.* as *
      | stats values(job_name) as job_names
        BY workflow_id workflow_name user
           commit_message url branch
      | lookup mandatory_job_for_workflow workflow_name OUTPUTNEW job_name AS mandatory_job
      | search mandatory_job=*
      | eval mandatory_job_executed=if(like(job_names, "%".mandatory_job."%"), 1, 0)
      | where mandatory_job_executed=0
      | eval phase="build"
      | rex field=url "(?<repository>[^\/]*\/[^\/]*)$"
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `circle_ci_disable_security_job_filter`
how_to_implement: You must index CircleCI logs.
known_false_positives: No false positives have been identified at this time.
references: []
drilldown_searches:
    - name: View the detection results for - "$user$"
      search: '%original_detection_search% | search  user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 20
          message: Disable security job $mandatory_job$ in workflow $workflow_name$ from user $user$
analytic_story:
    - Dev Sec Ops
asset_type: CircleCI
mitre_attack_id:
    - T1554
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: network
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1554/circle_ci_disable_security_job/circle_ci_disable_security_job.json
          sourcetype: circleci
          source: circleci
      test_type: unit

Stages and Predicates

Stage 1: `search`

`circleci`

Stage 2: `rename`

| rename vcs.committer_name as user vcs.subject as commit_message vcs.url as url workflows.* as *

Stage 3: `stats`

| stats values(job_name) as job_names
    BY workflow_id workflow_name user
       commit_message url branch

Stage 4: `lookup`

| lookup mandatory_job_for_workflow workflow_name OUTPUTNEW job_name AS mandatory_job

Lookup table: mandatory_job_for_workflow
Key field: workflow_name
Output columns: ['job_name', 'mandatory_job']

Stage 5: `search`

| search mandatory_job=*

Stage 6: `eval`

| eval mandatory_job_executed=if(like(job_names, "%".mandatory_job."%"), 1, 0)

mandatory_job_executed =

iflike(job_names, concat("%", mandatory_job, "%"))1

else0

Stage 7: `where`

| where mandatory_job_executed=0

Stage 8: `eval`

| eval phase="build"

Stage 9: `rex`

| rex field=url "(?<repository>[^\/]*\/[^\/]*)$"

Stage 10: `search`

| `security_content_ctime(firstTime)`

Stage 11: `search`

| `security_content_ctime(lastTime)`

Stage 12: `search`

| `circle_ci_disable_security_job_filter`

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
`mandatory_job`	eq	`*`
`mandatory_job_executed`	eq	`0`
`sourcetype`	eq	`circleci`

`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)

Circle CI Disable Security Job

MITRE ATT&CK coverage

Rule body splunk

Stages and Predicates

Stage 1: `search`

Stage 2: `rename`

Stage 3: `stats`

Stage 4: `lookup`

Stage 5: `search`

Stage 6: `eval`

Stage 7: `where`

Stage 8: `eval`

Stage 9: `rex`

Stage 10: `search`

Stage 11: `search`

Stage 12: `search`

Indicators

Keyboard shortcuts

Search operators

Circle CI Disable Security Job

MITRE ATT&CK coverage

Rule body splunk

Stages and Predicates

Stage 1: search

Stage 2: rename

Stage 3: stats

Stage 4: lookup

Stage 5: search

Stage 6: eval

Stage 7: where

Stage 8: eval

Stage 9: rex

Stage 10: search

Stage 11: search

Stage 12: search

Indicators

Stage 1: `search`

Stage 2: `rename`

Stage 3: `stats`

Stage 4: `lookup`

Stage 5: `search`

Stage 6: `eval`

Stage 7: `where`

Stage 8: `eval`

Stage 9: `rex`

Stage 10: `search`

Stage 11: `search`

Stage 12: `search`