AWS GuardDuty High Severity Finding

Severity: high
Log types: AWS.GuardDuty
Tags: AWS
Reference: https://docs.aws.amazon.com/guardduty/latest/ug/guardduty_findings.html#guardduty_findings-severity
Source: github.com/panther-labs/panther-analysis

A high-severity GuardDuty finding has been identified.

Rule body yaml

AnalysisType: rule
Filename: aws_guardduty_high_sev_findings.py
RuleID: "AWS.GuardDuty.HighSeverityFinding"
DisplayName: "AWS GuardDuty High Severity Finding"
Enabled: true
LogTypes:
  - AWS.GuardDuty
Tags:
  - AWS
Severity: High
DedupPeriodMinutes: 60
Description: >
  A high-severity GuardDuty finding has been identified.
Runbook: >
  Search related logs to understand the root cause of the activity.
  Search the Panther Summary Attribute type value in https://docs.aws.amazon.com/guardduty/latest/ug/guardduty_finding-types-active.html for additional details.
Reference: https://docs.aws.amazon.com/guardduty/latest/ug/guardduty_findings.html#guardduty_findings-severity
SummaryAttributes:
  - severity
  - type
  - title
  - p_any_domain_names
  - p_any_aws_arns
  - p_any_aws_account_ids
Tests:
  - Name: High Sev Finding
    ExpectedResult: true
    Log:
      {
        "schemaVersion": "2.0",
        "accountId": "123456789012",
        "region": "us-east-1",
        "partition": "aws",
        "arn": "arn:aws:guardduty:us-west-2:123456789012:detector/111111bbbbbbbbbb5555555551111111/finding/90b82273685661b9318f078d0851fe9a",
        "type": "PrivilegeEscalation:IAMUser/AdministrativePermissions",
        "service":
          {
            "serviceName": "guardduty",
            "detectorId": "111111bbbbbbbbbb5555555551111111",
            "action":
              {
                "actionType": "AWS_API_CALL",
                "awsApiCallAction":
                  {
                    "api": "PutRolePolicy",
                    "serviceName": "iam.amazonaws.com",
                    "callerType": "Domain",
                    "domainDetails":
                      { "domain": "cloudformation.amazonaws.com" },
                    "affectedResources":
                      {
                        "AWS::IAM::Role": "arn:aws:iam::123456789012:role/IAMRole",
                      },
                  },
              },
            "resourceRole": "TARGET",
            "additionalInfo": {},
            "evidence": null,
            "eventFirstSeen": "2020-02-14T17:59:17Z",
            "eventLastSeen": "2020-02-14T17:59:17Z",
            "archived": false,
            "count": 1,
          },
        "severity": 8,
        "id": "eeb88ab56556eb7771b266670dddee5a",
        "createdAt": "2020-02-14T18:12:22.316Z",
        "updatedAt": "2020-02-14T18:12:22.316Z",
        "title": "Principal AssumedRole:IAMRole attempted to add a policy to themselves that is highly permissive.",
        "description": "Principal AssumedRole:IAMRole attempted to add a highly permissive policy to themselves.",
      }
  - Name: High Sev Finding As Sample Data
    ExpectedResult: false
    Log:
      {
        "schemaVersion": "2.0",
        "accountId": "123456789012",
        "region": "us-east-1",
        "partition": "aws",
        "arn": "arn:aws:guardduty:us-west-2:123456789012:detector/111111bbbbbbbbbb5555555551111111/finding/90b82273685661b9318f078d0851fe9a",
        "type": "PrivilegeEscalation:IAMUser/AdministrativePermissions",
        "service":
          {
            "serviceName": "guardduty",
            "detectorId": "111111bbbbbbbbbb5555555551111111",
            "action":
              {
                "actionType": "AWS_API_CALL",
                "awsApiCallAction":
                  {
                    "api": "PutRolePolicy",
                    "serviceName": "iam.amazonaws.com",
                    "callerType": "Domain",
                    "domainDetails":
                      { "domain": "cloudformation.amazonaws.com" },
                    "affectedResources":
                      {
                        "AWS::IAM::Role": "arn:aws:iam::123456789012:role/IAMRole",
                      },
                  },
              },
            "resourceRole": "TARGET",
            "additionalInfo": { "sample": true },
            "evidence": null,
            "eventFirstSeen": "2020-02-14T17:59:17Z",
            "eventLastSeen": "2020-02-14T17:59:17Z",
            "archived": false,
            "count": 1,
          },
        "severity": 8,
        "id": "eeb88ab56556eb7771b266670dddee5a",
        "createdAt": "2020-02-14T18:12:22.316Z",
        "updatedAt": "2020-02-14T18:12:22.316Z",
        "title": "Principal AssumedRole:IAMRole attempted to add a policy to themselves that is highly permissive.",
        "description": "Principal AssumedRole:IAMRole attempted to add a highly permissive policy to themselves.",
      }

Detection logic

Condition

service.additionalInfo.sample is_null
severity ge "7.0"
severity le "8.9"

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
`service.additionalInfo.sample`	is_null	(no value, null check)
`severity`	ge	`7.0`
`severity`	le	`8.9`

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
`description`
`severity`
`id`
`type`
`resource`
`service`
`accountId`
`title`

`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)