GCP Audit Logs - Data Access Logging Exemption Added for Principal

Status: available
Severity: high
Time window: 1h
Group by: AuthEmail, CallerIpAddress, ExemptedAccountName, ExemptedMember, GCPResourceName, LogName, MethodName, PrincipalEmail, ProjectId, ServiceName, UserAgent
Source: github.com/Azure/Azure-Sentinel

'Detects when a principal (user or service account) is exempted from GCP data access audit logging. This is a critical security event as it reduces visibility into privileged operations and may indicate an attempt to hide malicious activity. Adversaries may exempt their accounts from audit logging to evade detection while performing reconnaissance, privilege escalation, or data exfiltration. This rule monitors SetIamPolicy operations that add audit log exemptions for ADMIN_READ, DATA_READ, or DATA_WRITE log types.'

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1078.004` Valid Accounts: Cloud Accounts
Stealth	`T1078.004` Valid Accounts: Cloud Accounts, `T1562.008` Impair Defenses: Disable or Modify Cloud Logs

Rules detecting the same action

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

GCP Cloud Audit Logging Removed From All Services (YARA-L)
GCP Exempt Principals From Audit Log (YARA-L)

Rule body kusto

id: b7da45ce-fcc8-43c7-a37c-c08454579d26
name: GCP Audit Logs - Data Access Logging Exemption Added for Principal
description: |
  'Detects when a principal (user or service account) is exempted from GCP data access audit logging.
  This is a critical security event as it reduces visibility into privileged operations and may indicate an attempt to hide malicious activity.
  Adversaries may exempt their accounts from audit logging to evade detection while performing reconnaissance, privilege escalation, or data exfiltration.
  This rule monitors SetIamPolicy operations that add audit log exemptions for ADMIN_READ, DATA_READ, or DATA_WRITE log types.'
severity: High
status: Available
requiredDataConnectors:
  - connectorId: GCPAuditLogsDefinition
    dataTypes:
      - GCPAuditLogs
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - DefenseEvasion
  - PrivilegeEscalation
relevantTechniques:
  - T1562.008
  - T1078.004
tags:
  - Cloud Security
  - Audit Logging
  - Defense Evasion
query: |
 GCPAuditLogs
  | where ServiceName == "cloudresourcemanager.googleapis.com"
  | where MethodName == "SetIamPolicy"
  | where GCPResourceType == "project" and Severity == "NOTICE"
  | where isnotempty(ServiceData)
  | extend ServiceDataJson = parse_json(ServiceData)
  | extend PolicyDelta = ServiceDataJson.policyDelta.auditConfigDeltas
  | where isnotempty(PolicyDelta)
  | mv-expand ConfigDelta = PolicyDelta
  | where ConfigDelta.action == "ADD"
  | extend LogType = tostring(ConfigDelta.logType)
  | where LogType in ("ADMIN_READ", "DATA_READ", "DATA_WRITE")
  | extend 
      ExemptedMember = tostring(ConfigDelta.exemptedMember),
      ServiceAffected = tostring(ConfigDelta.service),
      RequestMetadataJson = parse_json(RequestMetadata),
      AuthInfoJson = parse_json(AuthenticationInfo)
  | where isnotempty(ExemptedMember)
  | extend 
      CallerIpAddress = tostring(RequestMetadataJson.callerIp),
      UserAgent = tostring(RequestMetadataJson.callerSuppliedUserAgent),
      AuthEmail = tostring(AuthInfoJson.principalEmail),
      ExemptedAccountName = tostring(split(ExemptedMember, ":")[1])
  | summarize 
      ExemptedLogTypes = make_set(LogType, 10),
      ExemptedServices = make_set(ServiceAffected, 50),
      FirstExemption = min(TimeGenerated),
      LastExemption = max(TimeGenerated)
      by PrincipalEmail, ProjectId, GCPResourceName, ExemptedMember, 
         CallerIpAddress, UserAgent, LogName, ExemptedAccountName, MethodName, ServiceName, AuthEmail
  | extend
      AccountName = tostring(split(PrincipalEmail, "@")[0]), 
      AccountUPNSuffix = tostring(split(PrincipalEmail, "@")[1])
  | project TimeGenerated = LastExemption,
      PrincipalEmail,
      ProjectId,
      ResourceName = GCPResourceName,
      ExemptedMember,
      ExemptedAccountName,
      ExemptedLogTypes,
      ExemptedServices,
      FirstExemption,
      LastExemption,
      CallerIpAddress,
      UserAgent,
      AuthEmail,
      MethodName,
      ServiceName,
      LogName,
      AccountName,
      AccountUPNSuffix
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: PrincipalEmail
      - identifier: Name
        columnName: AccountName
      - identifier: UPNSuffix
        columnName: AccountUPNSuffix
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: CallerIpAddress
  - entityType: CloudApplication
    fieldMappings:
      - identifier: Name
        columnName: ProjectId
      - identifier: InstanceName
        columnName: ResourceName
customDetails:
  ProjectId: ProjectId
  ExemptedMember: ExemptedMember
  ExemptedAccountName: ExemptedAccountName
  ExemptedLogTypes: ExemptedLogTypes
  ExemptedServices: ExemptedServices
  UserAgent: UserAgent
alertDetailsOverride:
  alertDisplayNameFormat: "GCP Data Access Logging Exemption Added for {{ExemptedAccountName}} by {{PrincipalEmail}} in Service {{ExemptedServices}}"
  alertDescriptionFormat: |-
    Principal {{ExemptedAccountName}} added as exception from Data Access logging in project {{ProjectId}} for Service {{ExemptedServices}}.
    This action reduces audit visibility and may indicate an attempt to evade detection. Verify this change was authorized and investigate any suspicious activity performed by the exempted principal.
version: 1.0.0
kind: Scheduled

Stages and Predicates

Stage 1: `source`

GCPAuditLogs

Stage 2: `where`

| where ServiceName == "cloudresourcemanager.googleapis.com"

Stage 3: `where`

| where MethodName == "SetIamPolicy"

Stage 4: `where`

| where GCPResourceType == "project" and Severity == "NOTICE"

Stage 5: `where`

| where isnotempty(ServiceData)

Stage 6: `extend`

| extend ServiceDataJson = parse_json(ServiceData)

Stage 7: `extend`

| extend PolicyDelta = ServiceDataJson.policyDelta.auditConfigDeltas

Stage 8: `where`

| where isnotempty(PolicyDelta)

Stage 9: `mv-expand`

| mv-expand ConfigDelta = PolicyDelta

Stage 10: `where`

| where ConfigDelta.action == "ADD"

Stage 11: `extend`

| extend LogType = tostring(ConfigDelta.logType)

Stage 12: `where`

| where LogType in ("ADMIN_READ", "DATA_READ", "DATA_WRITE")

Stage 13: `extend`

| extend 
     ExemptedMember = tostring(ConfigDelta.exemptedMember),
     ServiceAffected = tostring(ConfigDelta.service),
     RequestMetadataJson = parse_json(RequestMetadata),
     AuthInfoJson = parse_json(AuthenticationInfo)

Stage 14: `where`

| where isnotempty(ExemptedMember)

Stage 15: `extend`

| extend 
     CallerIpAddress = tostring(RequestMetadataJson.callerIp),
     UserAgent = tostring(RequestMetadataJson.callerSuppliedUserAgent),
     AuthEmail = tostring(AuthInfoJson.principalEmail),
     ExemptedAccountName = tostring(split(ExemptedMember, ":")[1])

Stage 16: `summarize`

| summarize 
     ExemptedLogTypes = make_set(LogType, 10),
     ExemptedServices = make_set(ServiceAffected, 50),
     FirstExemption = min(TimeGenerated),
     LastExemption = max(TimeGenerated)
     by PrincipalEmail, ProjectId, GCPResourceName, ExemptedMember, 
        CallerIpAddress, UserAgent, LogName, ExemptedAccountName, MethodName, ServiceName, AuthEmail

Stage 17: `extend`

| extend
     AccountName = tostring(split(PrincipalEmail, "@")[0]), 
     AccountUPNSuffix = tostring(split(PrincipalEmail, "@")[1])

Stage 18: `project`

| project TimeGenerated = LastExemption,
     PrincipalEmail,
     ProjectId,
     ResourceName = GCPResourceName,
     ExemptedMember,
     ExemptedAccountName,
     ExemptedLogTypes,
     ExemptedServices,
     FirstExemption,
     LastExemption,
     CallerIpAddress,
     UserAgent,
     AuthEmail,
     MethodName,
     ServiceName,
     LogName,
     AccountName,
     AccountUPNSuffix

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
`ExemptedMember`	is_not_null	(no value, null check)
`GCPResourceType`	eq	`project` transforms: `cased`
`LogType`	in	`ADMIN_READ` transforms: `cased` `DATA_READ` transforms: `cased` `DATA_WRITE` transforms: `cased`
`MethodName`	eq	`SetIamPolicy` transforms: `cased`
`PolicyDelta`	is_not_null	(no value, null check)
`ServiceData`	is_not_null	(no value, null check)
`ServiceName`	eq	`cloudresourcemanager.googleapis.com` transforms: `cased`
`Severity`	eq	`NOTICE` transforms: `cased`
`action`	eq	`ADD` 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
`AccountName`	`project`
`AccountUPNSuffix`	`project`
`AuthEmail`	`project`
`CallerIpAddress`	`project`
`ExemptedAccountName`	`project`
`ExemptedLogTypes`	`project`
`ExemptedMember`	`project`
`ExemptedServices`	`project`
`FirstExemption`	`project`
`LastExemption`	`project`
`LogName`	`project`
`MethodName`	`project`
`PrincipalEmail`	`project`
`ProjectId`	`project`
`ResourceName`	`project`
`ServiceName`	`project`
`TimeGenerated`	`project`
`UserAgent`	`project`

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`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)

GCP Audit Logs - Data Access Logging Exemption Added for Principal

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `where`

Stage 6: `extend`

Stage 7: `extend`

Stage 8: `where`

Stage 9: `mv-expand`

Stage 10: `where`

Stage 11: `extend`

Stage 12: `where`

Stage 13: `extend`

Stage 14: `where`

Stage 15: `extend`

Stage 16: `summarize`

Stage 17: `extend`

Stage 18: `project`

Indicators

Output fields

Keyboard shortcuts

Search operators

GCP Audit Logs - Data Access Logging Exemption Added for Principal

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: where

Stage 6: extend

Stage 7: extend

Stage 8: where

Stage 9: mv-expand

Stage 10: where

Stage 11: extend

Stage 12: where

Stage 13: extend

Stage 14: where

Stage 15: extend

Stage 16: summarize

Stage 17: extend

Stage 18: project

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `where`

Stage 6: `extend`

Stage 7: `extend`

Stage 8: `where`

Stage 9: `mv-expand`

Stage 10: `where`

Stage 11: `extend`

Stage 12: `where`

Stage 13: `extend`

Stage 14: `where`

Stage 15: `extend`

Stage 16: `summarize`

Stage 17: `extend`

Stage 18: `project`