AWS CloudTrail Important Change

Status: test
Severity: medium
Log source: product aws, service cloudtrail
Author: vitaliy0x1
Source: github.com/SigmaHQ/sigma

Detects disabling, deleting and updating of a Trail

MITRE ATT&CK coverage

Tactic	Techniques
Defense Impairment	`T1685.002` Disable or Modify Tools: Disable or Modify Cloud Log

Event coverage

Provider	Event
AWS-cloudtrail	DeleteTrail
AWS-cloudtrail	StopLogging
AWS-cloudtrail	UpdateTrail

Rules detecting the same action

Other rules on this platform that filter on the same API call or operation.

Attempt To Delete A CloudTrail Log (Sigma)
Attempt To Modify CloudTrail Log Settings (Sigma)
Attempt To Stop CloudTrail Logging (Sigma)
AWS CloudTrail Log Deleted (Elastic)
AWS CloudTrail Log Suspended (Elastic)
AWS CloudTrail Log Updated (Elastic)
AWS Defense Evasion Delete Cloudtrail (Splunk)
AWS Defense Evasion Stop Logging Cloudtrail (Splunk)

Rule body yaml

title: AWS CloudTrail Important Change
id: 4db60cc0-36fb-42b7-9b58-a5b53019fb74
status: test
description: Detects disabling, deleting and updating of a Trail
references:
    - https://docs.aws.amazon.com/awscloudtrail/latest/userguide/best-practices-security.html
author: vitaliy0x1
date: 2020-01-21
modified: 2022-10-09
tags:
    - attack.defense-impairment
    - attack.t1685.002
logsource:
    product: aws
    service: cloudtrail
detection:
    selection_source:
        eventSource: cloudtrail.amazonaws.com
        eventName:
            - StopLogging
            - UpdateTrail
            - DeleteTrail
    condition: selection_source
falsepositives:
    - Valid change in a Trail
level: medium

Stages and Predicates

Stage 0: `condition`

selection_source

Stage 1: `selection_source`

selection_source:
    eventSource: cloudtrail.amazonaws.com
    eventName:
        - StopLogging
        - UpdateTrail
        - DeleteTrail

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
`eventName`	eq	`DeleteTrail` `StopLogging` `UpdateTrail`
`eventSource`	eq	`cloudtrail.amazonaws.com`

`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)

AWS CloudTrail Important Change

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_source`

Indicators

Keyboard shortcuts

Search operators

AWS CloudTrail Important Change

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_source

Indicators

Stage 0: `condition`

Stage 1: `selection_source`