AWSCloudTrail - Creating keys with encrypt policy without MFA

Status: available
Severity: medium
Time window: 1d
Source: github.com/Azure/Azure-Sentinel

Identifies AWS KMS key creation or policy changes that allow kms:Encrypt or kms:* to any principal. This configuration can expose encryption capability outside approved boundaries and should be investigated as overly permissive or malicious.

MITRE ATT&CK coverage

Tactic	Techniques
Impact	`T1485` Data Destruction

Rules detecting the same action

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

Rule body kusto

id: 454133a7-5427-4a7c-bdc4-0adfa84dda16
name: AWSCloudTrail - Creating keys with encrypt policy without MFA
description: |
  Identifies AWS KMS key creation or policy changes that allow `kms:Encrypt` or `kms:*` to any principal. This configuration can expose encryption capability outside approved boundaries and should be investigated as overly permissive or malicious.
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: AWS
    dataTypes:
      - AWSCloudTrail
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Impact
relevantTechniques:
  - T1485
query: |
    let check_actions = AWSCloudTrail
    | where EventName in ("CreateKey", "PutKeyPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
    | extend state=parse_json(parse_json(replace_string(tostring(parse_json(RequestParameters)['policy']),'\\"','"')).['Statement'])
    | mv-expand state
    | extend Action= tostring(parse_json(state.['Action'][0])), Effect=tostring(parse_json(state.['Effect'])),
             Principal=tostring(parse_json(state.['Principal']))
    | where Action in ("kms:Encrypt", "kms:*") and (Effect == 'Allow') and (Principal has "*")
    | distinct AwsEventId;
    AWSCloudTrail
    | where EventName in ("CreateKey", "PutKeyPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
    | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
    | extend UserName = tostring(split(UserIdentityArn, '/')[-1])
    | extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
    | extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
      AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
    | join kind=inner (check_actions) on AwsEventId
    | extend timestamp = TimeGenerated
    | project-away AwsEventId1
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountName
      - identifier: UPNSuffix
        columnName: AccountUPNSuffix
      - identifier: CloudAppAccountId
        columnName: RecipientAccountId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SourceIpAddress
customDetails:
  AwsEventId: AwsEventId
  EventName: EventName
  UserIdentityArn: UserIdentityArn
alertDetailsOverride:
  alertDisplayNameFormat: 'AWS KMS key creation or policy update by {{AccountName}} without MFA'
  alertDescriptionFormat: 'KMS key creation or policy update by {{AccountName}} without MFA resulted in permissive encrypt access. AwsEventId: {{AwsEventId}}'
version: 1.0.3
kind: Scheduled

Stages and Predicates

Let binding: `check_actions`

let check_actions = AWSCloudTrail
| where EventName in ("CreateKey", "PutKeyPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
| extend state=parse_json(parse_json(replace_string(tostring(parse_json(RequestParameters)['policy']),'\\"','"')).['Statement'])
| mv-expand state
| extend Action= tostring(parse_json(state.['Action'][0])), Effect=tostring(parse_json(state.['Effect'])),
         Principal=tostring(parse_json(state.['Principal']))
| where Action in ("kms:Encrypt", "kms:*") and (Effect == 'Allow') and (Principal has "*")
| distinct AwsEventId;

Stage 1: `source`

AWSCloudTrail

Stage 2: `where`

| where EventName in ("CreateKey", "PutKeyPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)

Stage 3: `extend` (4 consecutive steps)

| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
| extend UserName = tostring(split(UserIdentityArn, '/')[-1])
| extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
| extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
  AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")

Stage 4: `join`

| join kind=inner (check_actions) on AwsEventId

Stage 5: `extend`

| extend timestamp = TimeGenerated

Stage 6: `project-away`

| project-away AwsEventId1

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
`Action`	in	`kms:*` transforms: `cased` `kms:Encrypt` transforms: `cased`
`Effect`	eq	`Allow` transforms: `cased`
`ErrorCode`	is_null	(no value, null check)
`ErrorMessage`	is_null	(no value, null check)
`EventName`	in	`CreateKey` transforms: `cased` `PutKeyPolicy` transforms: `cased`
`Principal`	match	`*` transforms: `term`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`UserIdentityArn`	`extend`
`UserName`	`extend`
`AccountName`	`extend`
`AccountUPNSuffix`	`extend`
`timestamp`	`extend`

`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)

AWSCloudTrail - Creating keys with encrypt policy without MFA

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Let binding: `check_actions`

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend` (4 consecutive steps)

Stage 4: `join`

Stage 5: `extend`

Stage 6: `project-away`

Indicators

Output fields

Keyboard shortcuts

Search operators

AWSCloudTrail - Creating keys with encrypt policy without MFA

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Let binding: check_actions

Stage 1: source

Stage 2: where

Stage 3: extend (4 consecutive steps)

Stage 4: join

Stage 5: extend

Stage 6: project-away

Indicators

Output fields

Let binding: `check_actions`

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend` (4 consecutive steps)

Stage 4: `join`

Stage 5: `extend`

Stage 6: `project-away`