GCP Org or Folder Policy Was Changed Manually

Severity: high
Compliance: GCP_CIS_1.3 1.8
Log types: GCP.AuditLog
Tags: GCP, Identity & Access Management, Persistence, Modify Authentication Process - Conditional Access Policies
Reference: https://cloud.google.com/iam/docs/granting-changing-revoking-access
Source: github.com/panther-labs/panther-analysis

Alert if a GCP Org or Folder Policy Was Changed Manually.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1556.009` Modify Authentication Process: Conditional Access Policies

Rules detecting the same action

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

GCP Admin Privileged Roles Added To Service Accounts (YARA-L)
GCP Corporate Email Not Used (Panther)
GCP Free Gmail Domains Added To IAM Policy (YARA-L)
GCP IAM - Disable Data Access Logging (Kusto)
GCP IAM - High privileged role added to service account (Kusto)

Rule body yaml

AnalysisType: rule
Filename: gcp_iam_org_folder_changes.py
RuleID: "GCP.IAM.OrgFolderIAMChanges"
DisplayName: "GCP Org or Folder Policy Was Changed Manually"
Enabled: true
DedupPeriodMinutes: 1440 # 24 hours
LogTypes:
  - GCP.AuditLog
Tags:
  - GCP
  - Identity & Access Management
  - Persistence
  - Modify Authentication Process - Conditional Access Policies 
Reports:
  GCP_CIS_1.3:
    - 1.8
  MITRE ATT&CK:
    - TA0003:T1556.009
Severity: High
Description: >
  Alert if a GCP Org or Folder Policy Was Changed Manually.
Runbook: |
  Contact the party that made the change.
  If it was intended to be temporary, ask for a window for rollback (< 24 hours).
  If it must be permanent, ask for change-management doc explaining why it was needed.
  Direct them to make the change in Terraform to avoid automated rollback.
  Grep for google_org and google_folder in terraform repos for places to
  put your new policy bindings.
Reference: https://cloud.google.com/iam/docs/granting-changing-revoking-access
SummaryAttributes:
  - severity
  - p_any_ip_addresses
Tests:
  - Name: Terraform User Agent
    ExpectedResult: true
    Log:
      {
        "insertId": "-lmjke7dbt7y",
        "logName": "organizations/888888888888/logs/cloudaudit.googleapis.com%2Factivity",
        "p_log_type": "GCP.AuditLog",
        "protoPayload":
          {
            "at_sign_type": "type.googleapis.com/google.cloud.audit.AuditLog",
            "authenticationInfo":
              {
                "principalEmail": "terraform@platform.iam.gserviceaccount.com",
                "principalSubject": "serviceAccount:terraform@platform.iam.gserviceaccount.com",
                "serviceAccountKeyName": "//iam.googleapis.com/projects/platform/serviceAccounts/terraform@platform.iam.gserviceaccount.com/keys/bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
              },
            "authorizationInfo":
              [
                {
                  "granted": true,
                  "permission": "resourcemanager.organizations.setIamPolicy",
                  "resource": "organizations/888888888888",
                  "resourceAttributes":
                    {
                      "name": "organizations/888888888888",
                      "service": "cloudresourcemanager.googleapis.com",
                      "type": "cloudresourcemanager.googleapis.com/Organization",
                    },
                },
              ],
            "methodName": "SetIamPolicy",
            "request":
              {
                "@type": "type.googleapis.com/google.iam.v1.SetIamPolicyRequest",
                "policy":
                  {
                    "bindings":
                      [
                        {
                          "members":
                            [
                              "joey.jojo@example.com",
                              "serviceAccount:terraform@platform.iam.gserviceaccount.com",
                            ],
                          "role": "roles/owner",
                        },
                      ],
                    "etag": "BwXcRFUAtX4=",
                  },
                "resource": "organizations/888888888888",
                "updateMask": "bindings,etag,auditConfigs",
              },
            "requestMetadata":
              {
                "callerIP": "100.100.100.100",
                "callerSuppliedUserAgent": "Terraform/0.13.2 terraform-provider-google/3.90.1",
                "destinationAttributes": {},
                "requestAttributes": {},
              },
            "resourceName": "organizations/888888888888",
            "response":
              {
                "@type": "type.googleapis.com/google.iam.v1.Policy",
                "bindings":
                  [
                    {
                      "members":
                        [
                          "joey.jojo@example.com",
                          "serviceAccount:terraform@platform.iam.gserviceaccount.com",
                        ],
                      "role": "roles/owner",
                    },
                  ],
                "etag": "BwXeRCtKxCw=",
              },
            "serviceData":
              {
                "@type": "type.googleapis.com/google.iam.v1.logging.AuditData",
                "policyDelta":
                  {
                    "bindingDeltas":
                      [
                        {
                          "action": "ADD",
                          "member": "user:backdoor@example.com",
                          "role": "roles/owner",
                        },
                      ],
                  },
              },
            "serviceName": "cloudresourcemanager.googleapis.com",
            "status": {},
          },
        "receiveTimestamp": "2022-05-05 14:00:49.450798551",
        "resource":
          {
            "labels": { "organization_id": "888888888888" },
            "type": "organization",
          },
        "severity": "NOTICE",
        "timestamp": "2022-05-05 14:00:48.814294000",
      }
  - Name: Manual Change
    ExpectedResult: true
    Log:
      {
        "insertId": "-yoga2udnx8s",
        "logName": "organizations/888888888888/logs/cloudaudit.googleapis.com%2Factivity",
        "p_log_type": "GCP.AuditLog",
        "protoPayload":
          {
            "@type": "type.googleapis.com/google.cloud.audit.AuditLog",
            "authenticationInfo": { "principalEmail": "chris@example.com" },
            "authorizationInfo":
              [
                {
                  "granted": true,
                  "permission": "resourcemanager.organizations.setIamPolicy",
                  "resource": "organizations/888888888888",
                  "resourceAttributes":
                    {
                      "name": "organizations/888888888888",
                      "service": "cloudresourcemanager.googleapis.com",
                      "type": "cloudresourcemanager.googleapis.com/Organization",
                    },
                },
              ],
            "methodName": "SetIamPolicy",
            "request":
              {
                "@type": "type.googleapis.com/google.iam.v1.SetIamPolicyRequest",
                "etag": "BwXYPRNtbqo=",
                "policy":
                  {
                    "bindings":
                      [
                        {
                          "members":
                            [
                              "user:chris@example.com",
                              "serviceAccount:diana@platform.iam.gserviceaccount.com",
                            ],
                          "role": "roles/owner",
                        },
                      ],
                  },
              },
            "receiveTimestamp": "2022-02-17T22:52:03.190032712Z",
            "requestMetadata":
              {
                "callerIp": "38.38.38.38",
                "callerSuppliedUserAgent": "Mozilla/5.0 Chrome/98.0.4758.102",
                "destinationAttributes": {},
                "requestAttributes": {},
              },
            "resource":
              {
                "labels": { "organization_id": "888888888888" },
                "type": "organization",
              },
            "resourceName": "organizations/888888888888",
            "response":
              {
                "@type": "type.googleapis.com/google.iam.v1.Policy",
                "bindings":
                  [
                    {
                      "members": ["user:chris@example.com"],
                      "role": "roles/owner",
                    },
                  ],
                "etag": "BwXYPp1Xs/Y=",
              },
            "serviceData":
              {
                "@type": "type.googleapis.com/google.iam.v1.logging.AuditData",
                "policyDelta":
                  {
                    "bindingDeltas":
                      [
                        {
                          "action": "REMOVE",
                          "member": "serviceAccount:diana@platform.iam.gserviceaccount.com",
                          "role": "roles/owner",
                        },
                      ],
                  },
              },
          },
        "serviceName": "cloudresourcemanager.googleapis.com",
        "severity": "NOTICE",
        "status": {},
        "timestamp": "2022-02-17T22:52:02.692083Z",
      }

Detection logic

Condition

protoPayload.methodName eq "SetIamPolicy"
logName starts_with "organizations" or logName starts_with "folder"
logName ends_with "/logs/cloudaudit.googleapis.com%2Factivity"

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
`logName`	ends_with	`/logs/cloudaudit.googleapis.com%2Factivity`
`logName`	starts_with	`folder` `organizations`
`protoPayload.methodName`	eq	`SetIamPolicy`

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
`actor`	`actor_user`
`policy_change`	`protoPayload.serviceData.policyDelta`
`caller_ip`	`protoPayload.requestMetadata.callerIP`
`user_agent`	`protoPayload.requestMetadata.callerSuppliedUserAgent`
`p_log_type`

`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)