AWSCloudTrail - Privilege escalation via CRUD S3 policy

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

Detects inline IAM policy updates that grant broad Amazon S3 create, read, update, and delete permissions. This type of policy expansion can be used to gain higher-impact access to cloud data and facilitate privilege escalation objectives.

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1098.003` Account Manipulation: Additional Cloud Roles

Rules detecting the same action

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

Rule body kusto

id: fc3061bb-319c-4fe9-abe2-f59899a6d907
name: AWSCloudTrail - Privilege escalation via CRUD S3 policy
description: |
  Detects inline IAM policy updates that grant broad Amazon S3 create, read, update, and delete permissions.
  This type of policy expansion can be used to gain higher-impact access to cloud data and facilitate privilege
  escalation objectives.
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: AWS
    dataTypes:
      - AWSCloudTrail
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - PrivilegeEscalation
relevantTechniques:
  - T1098.003
query: |
  AWSCloudTrail
  | where EventName in ("PutUserPolicy","PutRolePolicy","PutGroupPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
  | extend PolicyName = tostring(parse_json(RequestParameters).policyName)
  | extend Statement = parse_json(tostring((parse_json(RequestParameters).policyDocument))).Statement
  | mvexpand Statement
  | extend Action = parse_json(Statement).Action , Effect = tostring(parse_json(Statement).Effect), Resource = tostring(parse_json(Statement).Resource), Condition = tostring(parse_json(Statement).Condition)
  | extend Action = tostring(Action)
  | where Effect =~ "Allow" and (Action contains "s3:Create" and Action contains "s3:Get" and Action contains "s3:Put" and Action contains "s3:Delete") and Resource == "*" and Condition == ""
  | 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]), "")
  | distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityArn, UserIdentityUserName
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountName
      - identifier: UPNSuffix
        columnName: AccountUPNSuffix
      - identifier: CloudAppAccountId
        columnName: RecipientAccountId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SourceIpAddress
customDetails:
  PolicyName: PolicyName
  EventName: EventName
  UserIdentityArn: UserIdentityArn
  RecipientAccountId: RecipientAccountId
alertDetailsOverride:
  alertDisplayNameFormat: 'AWS S3 privilege escalation policy update by {{AccountName}}'
  alertDescriptionFormat: 'Detected {{EventName}} Event, updating inline S3 escalation policy {{PolicyName}} in account {{RecipientAccountId}}.'
version: 1.0.2
kind: Scheduled

Stages and Predicates

Stage 1: `source`

AWSCloudTrail

Stage 2: `where`

| where EventName in ("PutUserPolicy","PutRolePolicy","PutGroupPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)

Stage 3: `extend`

| extend PolicyName = tostring(parse_json(RequestParameters).policyName)

Stage 4: `extend`

| extend Statement = parse_json(tostring((parse_json(RequestParameters).policyDocument))).Statement

Stage 5: `mv-expand`

| mvexpand Statement

Stage 6: `extend`

| extend Action = parse_json(Statement).Action , Effect = tostring(parse_json(Statement).Effect), Resource = tostring(parse_json(Statement).Resource), Condition = tostring(parse_json(Statement).Condition)

Stage 7: `extend`

| extend Action = tostring(Action)

Stage 8: `where`

| where Effect =~ "Allow" and (Action contains "s3:Create" and Action contains "s3:Get" and Action contains "s3:Put" and Action contains "s3:Delete") and Resource == "*" and Condition == ""

Stage 9: `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 10: `distinct`

| distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityArn, UserIdentityUserName

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`	contains	`s3:Create` `s3:Delete` `s3:Get` `s3:Put`
`Effect`	eq	`Allow`
`ErrorCode`	is_null	(no value, null check)
`ErrorMessage`	is_null	(no value, null check)
`EventName`	in	`PutGroupPolicy` transforms: `cased` `PutRolePolicy` transforms: `cased` `PutUserPolicy` transforms: `cased`
`Resource`	eq	`*` transforms: `cased`

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
`PolicyName`	`extend`
`Statement`	`extend`
`Action`	`extend`
`Condition`	`extend`
`Effect`	`extend`
`Resource`	`extend`
`UserIdentityArn`	`extend`
`UserName`	`extend`
`AccountName`	`extend`
`AccountUPNSuffix`	`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 - Privilege escalation via CRUD S3 policy

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `extend`

Stage 5: `mv-expand`

Stage 6: `extend`

Stage 7: `extend`

Stage 8: `where`

Stage 9: `extend` (4 consecutive steps)

Stage 10: `distinct`

Indicators

Output fields

Keyboard shortcuts

Search operators

AWSCloudTrail - Privilege escalation via CRUD S3 policy

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: extend

Stage 4: extend

Stage 5: mv-expand

Stage 6: extend

Stage 7: extend

Stage 8: where

Stage 9: extend (4 consecutive steps)

Stage 10: distinct

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `extend`

Stage 5: `mv-expand`

Stage 6: `extend`

Stage 7: `extend`

Stage 8: `where`

Stage 9: `extend` (4 consecutive steps)

Stage 10: `distinct`