Circle CI Disable Security Step

Status: experimental
Severity: low
Group by: "owners{}", "vcs.committer_name", "vcs.subject", "vcs.url", job_id, job_name, step_names
Author: Patrick Bareiss, Splunk
Source: github.com/splunk/security_content

The following analytic detects the disablement of security steps in a CircleCI pipeline. It leverages CircleCI logs, using field renaming, joining, and statistical analysis to identify instances where mandatory security steps are not executed. This activity is significant because disabling security steps can introduce vulnerabilities, unauthorized changes, or malicious code into the pipeline. If confirmed malicious, this could lead to potential attacks, data breaches, or compromised infrastructure. Investigate by reviewing job names, commit details, and user information associated with the disablement, and examine any relevant artifacts and concurrent processes.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1554` Compromise Host Software Binary

Rule body splunk

name: Circle CI Disable Security Step
id: 72cb9de9-e98b-4ac9-80b2-5331bba6ea97
version: 9
creation_date: '2021-09-01'
modification_date: '2026-05-13'
author: Patrick Bareiss, Splunk
status: experimental
type: Anomaly
description: The following analytic detects the disablement of security steps in a CircleCI pipeline. It leverages CircleCI logs, using field renaming, joining, and statistical analysis to identify instances where mandatory security steps are not executed. This activity is significant because disabling security steps can introduce vulnerabilities, unauthorized changes, or malicious code into the pipeline. If confirmed malicious, this could lead to potential attacks, data breaches, or compromised infrastructure. Investigate by reviewing job names, commit details, and user information associated with the disablement, and examine any relevant artifacts and concurrent processes.
data_source:
    - CircleCI
search: |-
    `circleci`
      | rename workflows.job_id AS job_id
      | join job_id [
      | search `circleci`
      | stats values(name) as step_names count
        BY job_id job_name ]
      | stats count
        BY step_names job_id job_name
           vcs.committer_name vcs.subject vcs.url
           owners{}
      | rename vcs.* as * , owners{} as user
      | lookup mandatory_step_for_job job_name OUTPUTNEW step_name AS mandatory_step
      | search mandatory_step=*
      | eval mandatory_step_executed=if(like(step_names, "%".mandatory_step."%"), 1, 0)
      | where mandatory_step_executed=0
      | rex field=url "(?<repository>[^\/]*\/[^\/]*)$"
      | eval phase="build"
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `circle_ci_disable_security_step_filter`
how_to_implement: You must index CircleCI logs.
known_false_positives: No false positives have been identified at this time.
references: []
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 20
          message: Disable security step $mandatory_step$ in job $job_name$ 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_step/circle_ci_disable_security_step.json
          sourcetype: circleci
          source: circleci
      test_type: experimental
      description: This test is a legacy experimental test and may not be accurate.

Stages and Predicates

Stage 1: `search`

`circleci`

Stage 2: `rename`

| rename workflows.job_id AS job_id

Stage 3: `join`

| join job_id [
  | search `circleci`
  | stats values(name) as step_names count
    BY job_id job_name ]

Stage 4: `stats`

| stats count
    BY step_names job_id job_name
       vcs.committer_name vcs.subject vcs.url
       owners{}

Stage 5: `rename`

| rename vcs.* as * , owners{} as user

Stage 6: `lookup`

| lookup mandatory_step_for_job job_name OUTPUTNEW step_name AS mandatory_step

Lookup table: mandatory_step_for_job
Key field: job_name
Output columns: ['step_name', 'mandatory_step']

Stage 7: `search`

| search mandatory_step=*

Stage 8: `eval`

| eval mandatory_step_executed=if(like(step_names, "%".mandatory_step."%"), 1, 0)

mandatory_step_executed =

iflike(step_names, concat("%", mandatory_step, "%"))1

else0

Stage 9: `where`

| where mandatory_step_executed=0

Stage 10: `rex`

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

Stage 11: `eval`

| eval phase="build"

Stage 12: `search`

| `security_content_ctime(firstTime)`

Stage 13: `search`

| `security_content_ctime(lastTime)`

Stage 14: `search`

| `circle_ci_disable_security_step_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_step`	eq	`*`
`mandatory_step_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 Step

MITRE ATT&CK coverage

Rule body splunk

Stages and Predicates

Stage 1: `search`

Stage 2: `rename`

Stage 3: `join`

Stage 4: `stats`

Stage 5: `rename`

Stage 6: `lookup`

Stage 7: `search`

Stage 8: `eval`

Stage 9: `where`

Stage 10: `rex`

Stage 11: `eval`

Stage 12: `search`

Stage 13: `search`

Stage 14: `search`

Indicators

Keyboard shortcuts

Search operators

Circle CI Disable Security Step

MITRE ATT&CK coverage

Rule body splunk

Stages and Predicates

Stage 1: search

Stage 2: rename

Stage 3: join

Stage 4: stats

Stage 5: rename

Stage 6: lookup

Stage 7: search

Stage 8: eval

Stage 9: where

Stage 10: rex

Stage 11: eval

Stage 12: search

Stage 13: search

Stage 14: search

Indicators

Stage 1: `search`

Stage 2: `rename`

Stage 3: `join`

Stage 4: `stats`

Stage 5: `rename`

Stage 6: `lookup`

Stage 7: `search`

Stage 8: `eval`

Stage 9: `where`

Stage 10: `rex`

Stage 11: `eval`

Stage 12: `search`

Stage 13: `search`

Stage 14: `search`