GCP Corporate Email Not Used

Severity: low
Compliance: CIS 1.1
Log types: GCP.AuditLog
Tags: GCP, Identity & Access Management, Persistence:Create Account
Reference: https://cloud.google.com/iam/docs/service-account-overview
Source: github.com/panther-labs/panther-analysis

Unexpected domain is being used instead of a corporate email

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1136` Create Account

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 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)
GCP Org or Folder Policy Was Changed Manually (Panther)

Rule body yaml

AnalysisType: rule
Filename: gcp_iam_corp_email.py
RuleID: "GCP.IAM.CorporateEmail"
DisplayName: "GCP Corporate Email Not Used"
Enabled: true
DedupPeriodMinutes: 720 # 12 hours
LogTypes:
  - GCP.AuditLog
Tags:
  - GCP
  - Identity & Access Management
  - Persistence:Create Account
Reports:
  MITRE ATT&CK:
    - TA0003:T1136
  CIS:
    - 1.1
Severity: Low
Description: Unexpected domain is being used instead of a corporate email
Runbook: Remove the user
Reference: https://cloud.google.com/iam/docs/service-account-overview
SummaryAttributes:
  - severity
  - p_any_ip_addresses
  - p_any_domain_names
Tests:
  - Name: Gmail account added
    ExpectedResult: true
    Log:
      {
        "protoPayload":
          {
            "@type": "type.googleapis.com/google.cloud.audit.AuditLog",
            "status": {},
            "authenticationInfo": { "principalEmail": "test@runpanther.com" },
            "requestMetadata":
              {
                "callerIp": "136.24.229.58",
                "callerSuppliedUserAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36,gzip(gfe)",
                "requestAttributes": {},
                "destinationAttributes": {},
              },
            "serviceName": "cloudresourcemanager.googleapis.com",
            "methodName": "SetIamPolicy",
            "authorizationInfo":
              [
                {
                  "resource": "projects/western-verve-123456",
                  "permission": "resourcemanager.projects.setIamPolicy",
                  "granted": true,
                  "resourceAttributes": {},
                },
                {
                  "resource": "projects/western-verve-123456",
                  "permission": "resourcemanager.projects.setIamPolicy",
                  "granted": true,
                  "resourceAttributes": {},
                },
              ],
            "resourceName": "projects/western-verve-123456",
            "serviceData":
              {
                "@type": "type.googleapis.com/google.iam.v1.logging.AuditData",
                "policyDelta":
                  {
                    "bindingDeltas":
                      [
                        {
                          "action": "ADD",
                          "role": "roles/viewer",
                          "member": "user:username@gmail.com",
                        },
                      ],
                  },
              },
            "request":
              {
                "resource": "western-verve-123456",
                "@type": "type.googleapis.com/google.iam.v1.SetIamPolicyRequest",
                "policy":
                  {
                    "bindings":
                      [
                        {
                          "members": ["user:user-two@gmail.com"],
                          "role": "roles/appengine.serviceAdmin",
                        },
                        {
                          "members":
                            [
                              "serviceAccount:service-951849100836@compute-system.iam.gserviceaccount.com",
                            ],
                          "role": "roles/compute.serviceAgent",
                        },
                        {
                          "role": "roles/editor",
                          "members":
                            [
                              "serviceAccount:951849100836-compute@developer.gserviceaccount.com",
                              "serviceAccount:951849100836@cloudservices.gserviceaccount.com",
                            ],
                        },
                        {
                          "members": ["user:test@runpanther.com"],
                          "role": "roles/owner",
                        },
                        {
                          "members": ["user:user-two@gmail.com"],
                          "role": "roles/pubsub.admin",
                        },
                        {
                          "members":
                            [
                              "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                            ],
                          "role": "roles/pubsub.subscriber",
                        },
                        {
                          "members":
                            [
                              "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                            ],
                          "role": "roles/pubsub.viewer",
                        },
                        {
                          "role": "roles/resourcemanager.organizationAdmin",
                          "members": ["user:test@runpanther.com"],
                        },
                        {
                          "members": ["user:username@gmail.com"],
                          "role": "roles/viewer",
                        },
                      ],
                    "etag": "BwWk8zJlg2o=",
                  },
              },
            "response":
              {
                "etag": "BwWlp7rH6tY=",
                "bindings":
                  [
                    {
                      "members": ["user:user-two@gmail.com"],
                      "role": "roles/appengine.serviceAdmin",
                    },
                    {
                      "members":
                        [
                          "serviceAccount:service-951849100836@compute-system.iam.gserviceaccount.com",
                        ],
                      "role": "roles/compute.serviceAgent",
                    },
                    {
                      "members":
                        [
                          "serviceAccount:951849100836-compute@developer.gserviceaccount.com",
                          "serviceAccount:951849100836@cloudservices.gserviceaccount.com",
                        ],
                      "role": "roles/editor",
                    },
                    {
                      "members": ["user:test@runpanther.com"],
                      "role": "roles/owner",
                    },
                    {
                      "role": "roles/pubsub.admin",
                      "members": ["user:user-two@gmail.com"],
                    },
                    {
                      "role": "roles/pubsub.subscriber",
                      "members":
                        [
                          "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                        ],
                    },
                    {
                      "members":
                        [
                          "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                        ],
                      "role": "roles/pubsub.viewer",
                    },
                    {
                      "members": ["user:test@runpanther.com"],
                      "role": "roles/resourcemanager.organizationAdmin",
                    },
                    {
                      "members": ["user:username@gmail.com"],
                      "role": "roles/viewer",
                    },
                  ],
                "@type": "type.googleapis.com/google.iam.v1.Policy",
              },
          },
        "insertId": "mrbji0dal80",
        "resource":
          {
            "type": "project",
            "labels": { "project_id": "western-verve-123456" },
          },
        "timestamp": "2020-05-15T03:51:35.019Z",
        "severity": "NOTICE",
        "logName": "projects/western-verve-123456/logs/cloudaudit.googleapis.com%2Factivity",
        "receiveTimestamp": "2020-05-15T03:51:35.977314225Z",
      }
  - Name: Expected account added
    ExpectedResult: false
    Log:
      {
        "protoPayload":
          {
            "@type": "type.googleapis.com/google.cloud.audit.AuditLog",
            "status": {},
            "authenticationInfo": { "principalEmail": "test@runpanther.com" },
            "requestMetadata":
              {
                "callerIp": "136.24.229.58",
                "callerSuppliedUserAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36,gzip(gfe)",
                "requestAttributes": {},
                "destinationAttributes": {},
              },
            "serviceName": "cloudresourcemanager.googleapis.com",
            "methodName": "SetIamPolicy",
            "authorizationInfo":
              [
                {
                  "resource": "projects/western-verve-123456",
                  "permission": "resourcemanager.projects.setIamPolicy",
                  "granted": true,
                  "resourceAttributes": {},
                },
                {
                  "resource": "projects/western-verve-123456",
                  "permission": "resourcemanager.projects.setIamPolicy",
                  "granted": true,
                  "resourceAttributes": {},
                },
              ],
            "resourceName": "projects/western-verve-123456",
            "serviceData":
              {
                "@type": "type.googleapis.com/google.iam.v1.logging.AuditData",
                "policyDelta":
                  {
                    "bindingDeltas":
                      [
                        {
                          "action": "ADD",
                          "role": "roles/viewer",
                          "member": "user:username@runpanther.com",
                        },
                      ],
                  },
              },
            "request":
              {
                "resource": "western-verve-123456",
                "@type": "type.googleapis.com/google.iam.v1.SetIamPolicyRequest",
                "policy":
                  {
                    "bindings":
                      [
                        {
                          "members": ["user:user-two@gmail.com"],
                          "role": "roles/appengine.serviceAdmin",
                        },
                        {
                          "members":
                            [
                              "serviceAccount:service-951849100836@compute-system.iam.gserviceaccount.com",
                            ],
                          "role": "roles/compute.serviceAgent",
                        },
                        {
                          "role": "roles/editor",
                          "members":
                            [
                              "serviceAccount:951849100836-compute@developer.gserviceaccount.com",
                              "serviceAccount:951849100836@cloudservices.gserviceaccount.com",
                            ],
                        },
                        {
                          "members": ["user:test@runpanther.com"],
                          "role": "roles/owner",
                        },
                        {
                          "members": ["user:user-two@gmail.com"],
                          "role": "roles/pubsub.admin",
                        },
                        {
                          "members":
                            [
                              "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                            ],
                          "role": "roles/pubsub.subscriber",
                        },
                        {
                          "members":
                            [
                              "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                            ],
                          "role": "roles/pubsub.viewer",
                        },
                        {
                          "role": "roles/resourcemanager.organizationAdmin",
                          "members": ["user:test@runpanther.com"],
                        },
                        {
                          "members": ["user:username@gmail.com"],
                          "role": "roles/viewer",
                        },
                      ],
                    "etag": "BwWk8zJlg2o=",
                  },
              },
            "response":
              {
                "etag": "BwWlp7rH6tY=",
                "bindings":
                  [
                    {
                      "members": ["user:user-two@gmail.com"],
                      "role": "roles/appengine.serviceAdmin",
                    },
                    {
                      "members":
                        [
                          "serviceAccount:service-951849100836@compute-system.iam.gserviceaccount.com",
                        ],
                      "role": "roles/compute.serviceAgent",
                    },
                    {
                      "members":
                        [
                          "serviceAccount:951849100836-compute@developer.gserviceaccount.com",
                          "serviceAccount:951849100836@cloudservices.gserviceaccount.com",
                        ],
                      "role": "roles/editor",
                    },
                    {
                      "members": ["user:test@runpanther.com"],
                      "role": "roles/owner",
                    },
                    {
                      "role": "roles/pubsub.admin",
                      "members": ["user:user-two@gmail.com"],
                    },
                    {
                      "role": "roles/pubsub.subscriber",
                      "members":
                        [
                          "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                        ],
                    },
                    {
                      "members":
                        [
                          "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                        ],
                      "role": "roles/pubsub.viewer",
                    },
                    {
                      "members": ["user:test@runpanther.com"],
                      "role": "roles/resourcemanager.organizationAdmin",
                    },
                    {
                      "members": ["user:username@gmail.com"],
                      "role": "roles/viewer",
                    },
                  ],
                "@type": "type.googleapis.com/google.iam.v1.Policy",
              },
          },
        "insertId": "mrbji0dal80",
        "resource":
          {
            "type": "project",
            "labels": { "project_id": "western-verve-123456" },
          },
        "timestamp": "2020-05-15T03:51:35.019Z",
        "severity": "NOTICE",
        "logName": "projects/western-verve-123456/logs/cloudaudit.googleapis.com%2Factivity",
        "receiveTimestamp": "2020-05-15T03:51:35.977314225Z",
      }
  - Name: Expected GCP service account added by Service Agent Manager
    ExpectedResult: false
    Log:
      {
        "protoPayload":
          {
            "@type": "type.googleapis.com/google.cloud.audit.AuditLog",
            "status": {},
            "authenticationInfo":
              {
                "principalEmail": "service-agent-manager@system.gserviceaccount.com",
              },
            "requestMetadata":
              {
                "callerIp": "136.24.229.58",
                "callerSuppliedUserAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36,gzip(gfe)",
                "requestAttributes": {},
                "destinationAttributes": {},
              },
            "serviceName": "cloudresourcemanager.googleapis.com",
            "methodName": "SetIamPolicy",
            "authorizationInfo":
              [
                {
                  "resource": "projects/western-verve-123456",
                  "permission": "resourcemanager.projects.setIamPolicy",
                  "granted": true,
                  "resourceAttributes": {},
                },
                {
                  "resource": "projects/western-verve-123456",
                  "permission": "resourcemanager.projects.setIamPolicy",
                  "granted": true,
                  "resourceAttributes": {},
                },
              ],
            "resourceName": "projects/western-verve-123456",
            "serviceData":
              {
                "@type": "type.googleapis.com/google.iam.v1.logging.AuditData",
                "policyDelta":
                  {
                    "bindingDeltas":
                      [
                        {
                          "action": "ADD",
                          "role": "roles/logging.serviceAgent",
                          "member": "serviceAccount:service-951849100836@gcp-sa-logging.iam.gserviceaccount.com",
                        },
                      ],
                  },
              },
            "request":
              {
                "resource": "western-verve-123456",
                "@type": "type.googleapis.com/google.iam.v1.SetIamPolicyRequest",
                "policy":
                  {
                    "bindings":
                      [
                        {
                          "members": ["user:user-two@gmail.com"],
                          "role": "roles/appengine.serviceAdmin",
                        },
                        {
                          "members":
                            [
                              "serviceAccount:service-951849100836@compute-system.iam.gserviceaccount.com",
                            ],
                          "role": "roles/compute.serviceAgent",
                        },
                        {
                          "role": "roles/editor",
                          "members":
                            [
                              "serviceAccount:951849100836-compute@developer.gserviceaccount.com",
                              "serviceAccount:951849100836@cloudservices.gserviceaccount.com",
                            ],
                        },
                        {
                          "members": ["user:test@runpanther.com"],
                          "role": "roles/owner",
                        },
                        {
                          "members": ["user:user-two@gmail.com"],
                          "role": "roles/pubsub.admin",
                        },
                        {
                          "members":
                            [
                              "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                            ],
                          "role": "roles/pubsub.subscriber",
                        },
                        {
                          "members":
                            [
                              "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                            ],
                          "role": "roles/pubsub.viewer",
                        },
                        {
                          "role": "roles/resourcemanager.organizationAdmin",
                          "members": ["user:test@runpanther.com"],
                        },
                        {
                          "members":
                            [
                              "serviceAccount:service-951849100836@gcp-sa-logging.iam.gserviceaccount.com",
                            ],
                          "role": "roles/logging.ServiceAgent",
                        },
                      ],
                    "etag": "BwWk8zJlg2o=",
                  },
              },
            "response":
              {
                "etag": "BwWlp7rH6tY=",
                "bindings":
                  [
                    {
                      "members": ["user:user-two@gmail.com"],
                      "role": "roles/appengine.serviceAdmin",
                    },
                    {
                      "members":
                        [
                          "serviceAccount:service-951849100836@compute-system.iam.gserviceaccount.com",
                        ],
                      "role": "roles/compute.serviceAgent",
                    },
                    {
                      "members":
                        [
                          "serviceAccount:951849100836-compute@developer.gserviceaccount.com",
                          "serviceAccount:951849100836@cloudservices.gserviceaccount.com",
                        ],
                      "role": "roles/editor",
                    },
                    {
                      "members": ["user:test@runpanther.com"],
                      "role": "roles/owner",
                    },
                    {
                      "role": "roles/pubsub.admin",
                      "members": ["user:user-two@gmail.com"],
                    },
                    {
                      "role": "roles/pubsub.subscriber",
                      "members":
                        [
                          "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                        ],
                    },
                    {
                      "members":
                        [
                          "serviceAccount:pubsub-reader@western-verve-123456.iam.gserviceaccount.com",
                        ],
                      "role": "roles/pubsub.viewer",
                    },
                    {
                      "members": ["user:test@runpanther.com"],
                      "role": "roles/resourcemanager.organizationAdmin",
                    },
                    {
                      "members":
                        [
                          "serviceAccount:service-951849100836@gcp-sa-logging.iam.gserviceaccount.com",
                        ],
                      "role": "roles/logging.ServiceAgent",
                    },
                  ],
                "@type": "type.googleapis.com/google.iam.v1.Policy",
              },
          },
        "insertId": "mrbji0dal80",
        "resource":
          {
            "type": "project",
            "labels": { "project_id": "western-verve-123456" },
          },
        "timestamp": "2020-05-15T03:51:35.019Z",
        "severity": "NOTICE",
        "logName": "projects/western-verve-123456/logs/cloudaudit.googleapis.com%2Factivity",
        "receiveTimestamp": "2020-05-15T03:51:35.977314225Z",
      }

Detection logic

Condition

protoPayload.methodName eq "SetIamPolicy"
protoPayload.serviceData is_not_null
protoPayload.serviceData.policyDelta.bindingDeltas is_not_null

This rule also runs imperative logic the parser cannot express as a filter; the conditions above are the structured part it could extract.

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
`protoPayload.methodName`	eq	`SetIamPolicy`
`protoPayload.serviceData`	is_not_null	(no value, null check)
`protoPayload.serviceData.policyDelta.bindingDeltas`	is_not_null	(no value, null check)

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
`project_id`	`resource.labels.project_id`

`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)