AWS Decrypt SSM Parameters

Status: Experimental
Severity: medium
Compliance: Stratus Red Team aws.credential-access.ssm-retrieve-securestring-parameters
Log types: AWS.CloudTrail
Tags: AWS CloudTrail, Credential Access: Credentials from Password Stores
Reference: https://stratus-red-team.cloud/attack-techniques/AWS/aws.credential-access.ssm-retrieve-securestring-parameters/
Source: github.com/panther-labs/panther-analysis

Identify principals retrieving a high number of SSM Parameters of type 'SecretString'. This rule filters out known administrative roles that legitimately need bulk parameter access.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1555` Credentials from Password Stores

Rules detecting the same action

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

AWS Lateral Movement from Kubernetes SA via AssumeRoleWithWebIdentity (Elastic)

Rule body yaml

AnalysisType: rule
Filename: aws_ssm_decrypt_ssm_params.py
RuleID: "AWS.SSM.DecryptSSMParams"
DisplayName: AWS Decrypt SSM Parameters
Enabled: true
LogTypes:
  - AWS.CloudTrail
Severity: Medium
Reports:
  MITRE ATT&CK:
    - TA0006:T1555
  Stratus Red Team:
    - aws.credential-access.ssm-retrieve-securestring-parameters
Description: >
  Identify principals retrieving a high number of SSM Parameters of type 'SecretString'.
  This rule filters out known administrative roles that legitimately need bulk parameter access.
Threshold: 25
Reference: >
  https://stratus-red-team.cloud/attack-techniques/AWS/aws.credential-access.ssm-retrieve-securestring-parameters/
Runbook: |
  1. Query CloudTrail for all GetParameter and GetParameters events by userIdentity.arn with requestParameters.withDecryption=true in the 4 hours around this alert to identify the complete list of accessed SSM parameters
  2. Review the parameter names from the resources array to determine if they contain database credentials, API keys, or encryption keys, and assess the impact if those secrets are compromised
  3. Search CloudTrail for other suspicious API calls by the same userIdentity.arn and sourceIPAddress in the 24 hours before the first parameter access, looking for privilege escalation, IAM changes, or unusual resource access
SummaryAttributes:
  - sourceIpAddress
  - p_alert_context.accessedParams
Tags:
  - AWS CloudTrail
  - 'Credential Access: Credentials from Password Stores'
Status: Experimental
Tests:
  - Name: Single Secret Accessed in Single Event
    ExpectedResult: true
    Mocks:
      - objectName: get_string_set
        returnValue: '["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y"]'
      - objectName: put_string_set
        returnValue: ''
    Log:
      {
        "p_event_time": "2025-02-14 19:43:09.000000000",
        "p_log_type": "AWS.CloudTrail",
        "awsRegion": "us-west-2",
        "eventCategory": "Management",
        "eventID": "587e6d58-a653-4fd9-859f-367dc1bad98c",
        "eventName": "GetParameter",
        "eventSource": "ssm.amazonaws.com",
        "eventTime": "2025-02-14 19:43:09.000000000",
        "eventType": "AwsApiCall",
        "eventVersion": "1.11",
        "managementEvent": true,
        "readOnly": true,
        "recipientAccountId": "111122223333",
        "requestID": "a1f28efd-9f5b-4a13-9878-86f57de594dc",
        "requestParameters": {
          "name": "/credentials/stratus-red-team/credentials-25",
          "withDecryption": true
        },
        "resources": [
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-25"
          }
        ],
        "sourceIPAddress": "1.2.3.4",
        "tlsDetails": {
          "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
          "clientProvidedHostHeader": "ssm.us-west-2.amazonaws.com",
          "tlsVersion": "TLSv1.2"
        },
        "userAgent": "example-user-agent",
        "userIdentity": {
          "accessKeyId": "EXAMPLE_ACCESS_KEY",
          "accountId": "111122223333",
          "arn": "arn:aws:sts::111122223333:assumed-role/SampleRole/bobson.dugnutt",
          "principalId": "SAMPLE_PRINCIPAL_ID:bobson.dugnutt",
          "sessionContext": {
            "attributes": {
              "creationDate": "2025-02-14T19:42:05Z",
              "mfaAuthenticated": "false"
            },
            "sessionIssuer": {
              "accountId": "111122223333",
              "arn": "arn:aws:iam::111122223333:role/aws-reserved/sso.amazonaws.com/us-west-2/SampleRole",
              "principalId": "SAMPLE_PRINCIPAL_ID",
              "type": "Role",
              "userName": "SampleRole"
            }
          },
          "type": "AssumedRole"
        }
      }
  - Name: Multiple Secrets Accessed in Same Event
    ExpectedResult: true
    Mocks:
      - objectName: get_string_set
        returnValue: '["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o"]'
      - objectName: put_string_set
        returnValue: ''
    Log:
      {
        "p_event_time": "2025-02-14 19:42:57.000000000",
        "p_log_type": "AWS.CloudTrail",
        "awsRegion": "us-west-2",
        "eventCategory": "Management",
        "eventID": "ce59873d-6a27-4fa4-afc1-088fceba71e4",
        "eventName": "GetParameters",
        "eventSource": "ssm.amazonaws.com",
        "eventTime": "2025-02-14 19:42:57.000000000",
        "eventType": "AwsApiCall",
        "eventVersion": "1.11",
        "managementEvent": true,
        "readOnly": true,
        "recipientAccountId": "111122223333",
        "requestID": "b6cb0ea5-2366-47c3-a4e5-acc31bc6882a",
        "requestParameters": {
          "names": [
            "/credentials/stratus-red-team/credentials-10",
            "/credentials/stratus-red-team/credentials-11",
            "/credentials/stratus-red-team/credentials-12",
            "/credentials/stratus-red-team/credentials-15",
            "/credentials/stratus-red-team/credentials-24",
            "/credentials/stratus-red-team/credentials-30",
            "/credentials/stratus-red-team/credentials-31",
            "/credentials/stratus-red-team/credentials-32",
            "/credentials/stratus-red-team/credentials-36",
            "/credentials/stratus-red-team/credentials-40",
            "/credentials/stratus-red-team/credentials-41",
          ],
          "withDecryption": true
        },
        "resources": [
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-10"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-11"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-12"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-15"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-24"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-30"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-31"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-32"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-36"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-40"
          }
        ],
        "sourceIPAddress": "1.2.3.4",
        "tlsDetails": {
          "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
          "clientProvidedHostHeader": "ssm.us-west-2.amazonaws.com",
          "tlsVersion": "TLSv1.2"
        },
        "userAgent": "example-user-agent",
        "userIdentity": {
          "accessKeyId": "EXAMPLE_ACCESS_KEY",
          "accountId": "111122223333",
          "arn": "arn:aws:sts::111122223333:assumed-role/SampleRole/bobson.dugnutt",
          "principalId": "SAMPLE_PRINCIPAL_ID:bobson.dugnutt",
          "sessionContext": {
            "attributes": {
              "creationDate": "2025-02-14T19:42:05Z",
              "mfaAuthenticated": "false"
            },
            "sessionIssuer": {
              "accountId": "111122223333",
              "arn": "arn:aws:iam::111122223333:role/aws-reserved/sso.amazonaws.com/us-west-2/SampleRole",
              "principalId": "SAMPLE_PRINCIPAL_ID",
              "type": "Role",
              "userName": "SampleRole"
            }
          },
          "type": "AssumedRole"
        }
      }
  - Name: Multiple Secrets Accessed in Same Event With Prior Cached Parameters
    ExpectedResult: true
    Mocks:
      - objectName: get_string_set
        returnValue: '["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u"]'
      - objectName: put_string_set
        returnValue: ''
    Log:
      {
        "p_event_time": "2025-02-14 19:42:57.000000000",
        "p_log_type": "AWS.CloudTrail",
        "awsRegion": "us-west-2",
        "eventCategory": "Management",
        "eventID": "ce59873d-6a27-4fa4-afc1-088fceba71e4",
        "eventName": "GetParameters",
        "eventSource": "ssm.amazonaws.com",
        "eventTime": "2025-02-14 19:42:57.000000000",
        "eventType": "AwsApiCall",
        "eventVersion": "1.11",
        "managementEvent": true,
        "readOnly": true,
        "recipientAccountId": "111122223333",
        "requestID": "b6cb0ea5-2366-47c3-a4e5-acc31bc6882a",
        "requestParameters": {
          "names": [
            "/credentials/stratus-red-team/credentials-10",
            "/credentials/stratus-red-team/credentials-11",
            "/credentials/stratus-red-team/credentials-12",
            "/credentials/stratus-red-team/credentials-15",
            "/credentials/stratus-red-team/credentials-24"
          ],
          "withDecryption": true
        },
        "resources": [
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-10"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-11"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-12"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-15"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-24"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-30"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-31"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-32"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-36"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-40"
          }
        ],
        "sourceIPAddress": "1.2.3.4",
        "tlsDetails": {
          "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
          "clientProvidedHostHeader": "ssm.us-west-2.amazonaws.com",
          "tlsVersion": "TLSv1.2"
        },
        "userAgent": "example-user-agent",
        "userIdentity": {
          "accessKeyId": "EXAMPLE_ACCESS_KEY",
          "accountId": "111122223333",
          "arn": "arn:aws:sts::111122223333:assumed-role/SampleRole/bobson.dugnutt",
          "principalId": "SAMPLE_PRINCIPAL_ID:bobson.dugnutt",
          "sessionContext": {
            "attributes": {
              "creationDate": "2025-02-14T19:42:05Z",
              "mfaAuthenticated": "false"
            },
            "sessionIssuer": {
              "accountId": "111122223333",
              "arn": "arn:aws:iam::111122223333:role/aws-reserved/sso.amazonaws.com/us-west-2/SampleRole",
              "principalId": "SAMPLE_PRINCIPAL_ID",
              "type": "Role",
              "userName": "SampleRole"
            }
          },
          "type": "AssumedRole"
        }
      }
  - Name: Accessed Parameters Aren't Encrypted
    ExpectedResult: false
    Mocks:
      - objectName: get_string_set
        returnValue: '[]'
      - objectName: put_string_set
        returnValue: ''
    Log:
      {
        "p_event_time": "2025-02-14 19:42:57.000000000",
        "p_log_type": "AWS.CloudTrail",
        "awsRegion": "us-west-2",
        "eventCategory": "Management",
        "eventID": "ce59873d-6a27-4fa4-afc1-088fceba71e4",
        "eventName": "GetParameters",
        "eventSource": "ssm.amazonaws.com",
        "eventTime": "2025-02-14 19:42:57.000000000",
        "eventType": "AwsApiCall",
        "eventVersion": "1.11",
        "managementEvent": true,
        "readOnly": true,
        "recipientAccountId": "111122223333",
        "requestID": "b6cb0ea5-2366-47c3-a4e5-acc31bc6882a",
        "requestParameters": {
          "names": [
            "/credentials/stratus-red-team/credentials-10",
            "/credentials/stratus-red-team/credentials-11",
            "/credentials/stratus-red-team/credentials-12",
            "/credentials/stratus-red-team/credentials-15",
            "/credentials/stratus-red-team/credentials-24",
            "/credentials/stratus-red-team/credentials-30",
            "/credentials/stratus-red-team/credentials-31",
            "/credentials/stratus-red-team/credentials-32",
            "/credentials/stratus-red-team/credentials-36",
            "/credentials/stratus-red-team/credentials-40",
            "/credentials/stratus-red-team/credentials-41",
          ]
        },
        "resources": [
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-10"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-11"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-12"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-15"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-24"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-30"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-31"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-32"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-36"
          },
          {
            "accountId": "111122223333",
            "arn": "arn:aws:ssm:us-west-2:111122223333:parameter/credentials/stratus-red-team/credentials-40"
          }
        ],
        "sourceIPAddress": "1.2.3.4",
        "tlsDetails": {
          "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
          "clientProvidedHostHeader": "ssm.us-west-2.amazonaws.com",
          "tlsVersion": "TLSv1.2"
        },
        "userAgent": "example-user-agent",
        "userIdentity": {
          "accessKeyId": "EXAMPLE_ACCESS_KEY",
          "accountId": "111122223333",
          "arn": "arn:aws:sts::111122223333:assumed-role/SampleRole/bobson.dugnutt",
          "principalId": "SAMPLE_PRINCIPAL_ID:bobson.dugnutt",
          "sessionContext": {
            "attributes": {
              "creationDate": "2025-02-14T19:42:05Z",
              "mfaAuthenticated": "false"
            },
            "sessionIssuer": {
              "accountId": "111122223333",
              "arn": "arn:aws:iam::111122223333:role/aws-reserved/sso.amazonaws.com/us-west-2/SampleRole",
              "principalId": "SAMPLE_PRINCIPAL_ID",
              "type": "Role",
              "userName": "SampleRole"
            }
          },
          "type": "AssumedRole"
        }
      }
  - Name: Unrelated Event
    ExpectedResult: false
    Log:
      {
        "awsRegion": "us-west-2",
        "eventCategory": "Management",
        "eventID": "6c6de06f-eb03-44cd-a95f-928a780ce28a",
        "eventName": "DescribeParameters",
        "eventSource": "ssm.amazonaws.com",
        "eventTime": "2025-02-14 19:43:07.000000000",
        "eventType": "AwsApiCall",
        "eventVersion": "1.11",
        "managementEvent": true,
        "readOnly": true,
        "recipientAccountId": "111122223333",
        "requestID": "9ea104aa-d9af-415f-9c56-b7bb98c7c73f",
        "requestParameters": {
          "parameterFilters": [
            {
              "key": "Name",
              "option": "Equals",
              "values": [
                "/credentials/stratus-red-team/credentials-1"
              ]
            }
          ]
        },
        "sourceIPAddress": "1.2.3.4",
        "tlsDetails": {
          "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
          "clientProvidedHostHeader": "ssm.us-west-2.amazonaws.com",
          "tlsVersion": "TLSv1.2"
        },
        "userAgent": "example-user-agent",
        "userIdentity": {
          "accessKeyId": "EXAMPLE_ACCESS_KEY",
          "accountId": "111122223333",
          "arn": "arn:aws:sts::111122223333:assumed-role/SampleRole/bobson.dugnutt",
          "principalId": "SAMPLE_PRINCIPAL_ID:bobson.dugnutt",
          "sessionContext": {
            "attributes": {
              "creationDate": "2025-02-14T19:42:05Z",
              "mfaAuthenticated": "false"
            },
            "sessionIssuer": {
              "accountId": "111122223333",
              "arn": "arn:aws:iam::111122223333:role/aws-reserved/sso.amazonaws.com/us-west-2/SampleRole",
              "principalId": "SAMPLE_PRINCIPAL_ID",
              "type": "Role",
              "userName": "SampleRole"
            }
          },
          "type": "AssumedRole"
        }
      }

Detection logic

Condition

eventName in ["GetParameter", "GetParameters"]
requestParameters.withDecryption is_not_null
userIdentity.sessionContext.sessionIssuer.userName not 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.

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`userIdentity.sessionContext.sessionIssuer.userName`	is_not_null	(no value, null check)

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
`eventName`	in	`GetParameter` `GetParameters`
`requestParameters.withDecryption`	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
`eventName`
`eventSource`
`awsRegion`
`recipientAccountId`
`sourceIPAddress`
`userAgent`
`userIdentity`
`actor_user`

`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)