GCP Resource in Unused Region

Severity: medium
Log types: GCP.AuditLog
Tags: GCP, Database, Configuration Required, Defense Evasion:Unused/Unsupported Cloud Regions
Reference: https://cloud.google.com/docs/geography-and-regions
Source: github.com/panther-labs/panther-analysis

Adversaries may create cloud instances in unused geographic service regions in order to evade detection.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1535` Unused/Unsupported Cloud Regions

Rule body yaml

AnalysisType: rule
Filename: gcp_unused_regions.py
RuleID: "GCP.UnusedRegions"
DisplayName: "GCP Resource in Unused Region"
Enabled: false
DedupPeriodMinutes: 15
LogTypes:
  - GCP.AuditLog
Tags:
  - GCP
  - Database
  - Configuration Required
  - Defense Evasion:Unused/Unsupported Cloud Regions
Reports:
  MITRE ATT&CK:
    - TA0005:T1535
Severity: Medium
Description: >
  Adversaries may create cloud instances in unused geographic service regions in order to evade detection.
Runbook: Validate the user making the request and the resource created.
Reference: https://cloud.google.com/docs/geography-and-regions
SummaryAttributes:
  - severity
  - p_any_ip_addresses
  - p_any_domain_names
Tests:
  - Name: GCE Instance Terminated
    ExpectedResult: false
    Log:
      {
        "logName": "projects/western-verve-225918/logs/cloudaudit.googleapis.com%2Factivity",
        "severity": "NOTICE",
        "insertId": "81xwjyd5vh0",
        "resource":
          {
            "type": "gce_instance",
            "labels":
              {
                "instance_id": "5423650206360236277",
                "project_id": "western-verve-225918",
                "zone": "europe-north1-a",
              },
          },
        "timestamp": "2020-05-15 17:55:19.303000000",
        "receiveTimestamp": "2020-05-15 17:55:20.210068584",
        "operation":
          {
            "id": "operation-1589565287793-5a5b382538481-3da9816c-ce929997",
            "producer": "compute.googleapis.com",
            "last": true,
          },
        "protoPayload":
          {
            "@type": "type.googleapis.com/google.cloud.audit.AuditLog",
            "serviceName": "compute.googleapis.com",
            "methodName": "v1.compute.instances.delete",
            "resourceName": "projects/western-verve-225918/zones/europe-north1-a/instances/instance-3",
            "authenticationInfo":
              { "principalEmail": "jack.naglieri@runpanther.io" },
            "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),gzip(gfe)",
              },
            "request":
              { "@type": "type.googleapis.com/compute.instances.delete" },
          },
      }
  - Name: GCE Create Instance in SouthAmerica
    ExpectedResult: true
    Log:
      {
        "protoPayload":
          {
            "@type": "type.googleapis.com/google.cloud.audit.AuditLog",
            "authenticationInfo":
              { "principalEmail": "user.name@runpanther.io" },
            "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)",
              },
            "serviceName": "compute.googleapis.com",
            "methodName": "beta.compute.instances.insert",
            "resourceName": "projects/western-verve-123456/zones/asia-northeast1-b/instances/instance-5",
            "request":
              { "@type": "type.googleapis.com/compute.instances.insert" },
          },
        "insertId": "-5tqx5fd4mj8",
        "resource":
          {
            "type": "gce_instance",
            "labels":
              {
                "instance_id": "8498166540490993880",
                "project_id": "western-verve-123456",
                "zone": "southamerica-east1-b",
              },
          },
        "timestamp": "2020-05-15T17:15:42.415Z",
        "severity": "NOTICE",
        "logName": "projects/western-verve-123456/logs/cloudaudit.googleapis.com%2Factivity",
        "operation":
          {
            "id": "operation-1589562934964-5a5b2f61631d6-cc67597a-98092474",
            "producer": "compute.googleapis.com",
            "last": true,
          },
        "receiveTimestamp": "2020-05-15T17:15:43.377082868Z",
      }
  - Name: Create GCS in Asia
    ExpectedResult: true
    Log:
      {
        "protoPayload":
          {
            "@type": "type.googleapis.com/google.cloud.audit.AuditLog",
            "status": {},
            "authenticationInfo":
              { "principalEmail": "user.name@runpanther.io" },
            "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),gzip(gfe)",
                "requestAttributes":
                  { "time": "2020-05-15T17:25:07.810848781Z", "auth": {} },
                "destinationAttributes": {},
              },
            "serviceName": "storage.googleapis.com",
            "methodName": "storage.buckets.create",
            "authorizationInfo":
              [
                {
                  "resource": "projects/_/buckets/jacks-test-bucket-200",
                  "permission": "storage.buckets.create",
                  "granted": true,
                  "resourceAttributes": {},
                },
              ],
            "resourceName": "projects/_/buckets/jacks-test-bucket-200",
            "serviceData":
              {
                "@type": "type.googleapis.com/google.iam.v1.logging.AuditData",
                "policyDelta":
                  {
                    "bindingDeltas":
                      [
                        {
                          "action": "ADD",
                          "role": "roles/storage.legacyBucketOwner",
                          "member": "projectEditor:western-verve-123456",
                        },
                        {
                          "action": "ADD",
                          "role": "roles/storage.legacyBucketOwner",
                          "member": "projectOwner:western-verve-123456",
                        },
                        {
                          "action": "ADD",
                          "role": "roles/storage.legacyBucketReader",
                          "member": "projectViewer:western-verve-123456",
                        },
                      ],
                  },
              },
            "request":
              {
                "defaultObjectAcl":
                  {
                    "bindings":
                      [
                        {
                          "role": "roles/storage.legacyObjectReader",
                          "members": ["projectViewer:western-verve-123456"],
                        },
                        {
                          "members":
                            [
                              "projectOwner:western-verve-123456",
                              "projectEditor:western-verve-123456",
                            ],
                          "role": "roles/storage.legacyObjectOwner",
                        },
                      ],
                    "@type": "type.googleapis.com/google.iam.v1.Policy",
                  },
              },
            "resourceLocation": { "currentLocations": ["asia-northeast2"] },
          },
        "insertId": "c7rgc9c178",
        "resource":
          {
            "type": "gcs_bucket",
            "labels":
              {
                "bucket_name": "jacks-test-bucket-200",
                "project_id": "western-verve-123456",
                "location": "asia-northeast2",
              },
          },
        "timestamp": "2020-05-15T17:25:07.807169539Z",
        "severity": "NOTICE",
        "logName": "projects/western-verve-123456/logs/cloudaudit.googleapis.com%2Factivity",
        "receiveTimestamp": "2020-05-15T17:25:09.393448555Z",
      }
  - Name: "BigQuery access log (does not have standard attribute: resource.labels.location)"
    ExpectedResult: false
    Log:
      {
        "insertId": "v3a96bedw1us",
        "logName": "projects/western-verve-123456/logs/cloudaudit.googleapis.com%2Fdata_access",
        "protoPayload":
          {
            "at_sign_type": "type.googleapis.com/google.cloud.audit.AuditLog",
            "authenticationInfo":
              { "principalEmail": "user.name@runpanther.io" },
            "authorizationInfo":
              [
                {
                  "granted": true,
                  "permission": "bigquery.jobs.create",
                  "resource": "projects/western-verve-123456",
                  "resourceAttributes": {},
                },
              ],
            "methodName": "jobservice.insert",
            "requestMetadata":
              {
                "callerIP": "192.0.2.0",
                "callerSuppliedUserAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:92.0) Gecko/20100101 Firefox/92.0,gzip(gfe),gzip(gfe)",
                "destinationAttributes": {},
                "requestAttributes": {},
              },
            "resourceName": "projects/western-verve-123456/jobs",
            "serviceData":
              {
                "@type": "type.googleapis.com/google.cloud.bigquery.logging.v1.AuditData",
                "jobInsertRequest":
                  {
                    "resource":
                      {
                        "jobConfiguration":
                          {
                            "dryRun": true,
                            "query":
                              {
                                "createDisposition": "CREATE_IF_NEEDED",
                                "defaultDataset": {},
                                "destinationTable": {},
                                "query": "select * from no_such_table",
                                "queryPriority": "QUERY_INTERACTIVE",
                                "writeDisposition": "WRITE_EMPTY",
                              },
                          },
                        "jobName":
                          {
                            "location": "US",
                            "projectId": "western-verve-123456",
                          },
                      },
                  },
                "jobInsertResponse":
                  {
                    "resource":
                      {
                        "jobConfiguration": {},
                        "jobName": {},
                        "jobStatistics": {},
                        "jobStatus": { "error": {}, "state": "PENDING" },
                      },
                  },
              },
            "serviceName": "bigquery.googleapis.com",
            "status":
              {
                "code": 11,
                "message": "Syntax error: Unexpected end of script at [17:7]",
              },
          },
        "receiveTimestamp": "2021-10-19 16:09:26.351861539",
        "resource":
          {
            "labels": { "project_id": "western-verve-123456" },
            "type": "bigquery_resource",
          },
        "severity": "ERROR",
        "timestamp": "2021-10-19 16:09:26.013200000",
      }

Detection logic

Condition

protoPayload.methodName ends_with "insert" or protoPayload.methodName ends_with "create"

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`	ends_with	`create` `insert`

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)