OpenSearch-Docs-Cn/_security-analytics/api-tools/correlation-eng.md

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default	Correlation engine APIs	API tools	55

Correlation engine APIs

Correlation engine APIs allow you to create new correlation rules, view findings and correlations within a certain time window, and perform other tasks.

Create correlation rules between log types

This API is used to create correlation rules:

POST /_plugins/_security_analytics/correlation/rules

Request fields

Field	Type	Description
index	String	The name of the index used as the log source.
query	String	The query used to filter security logs for correlation.
category	String	The log type associated with the log source.

Example request

POST /_plugins/_security_analytics/correlation/rules
{
  "correlate": [
    {
      "index": "vpc_flow",
      "query": "dstaddr:4.5.6.7 or dstaddr:4.5.6.6",
      "category": "network"
    },
    {
      "index": "windows",
      "query": "winlog.event_data.SubjectDomainName:NTAUTHORI*",
      "category": "windows"
    },
    {
      "index": "ad_logs",
      "query": "ResultType:50126",
      "category": "ad_ldap"
    },
    {
      "index": "app_logs",
      "query": "endpoint:/customer_records.txt",
      "category": "others_application"
    }
  ]
}

{% include copy-curl.html %}

Example response

{
  "_id": "DxKEUIkBpIjg64IK4nXg",
  "_version": 1,
  "rule": {
    "name": null,
    "correlate": [
      {
        "index": "vpc_flow",
        "query": "dstaddr:4.5.6.7 or dstaddr:4.5.6.6",
        "category": "network"
      },
      {
        "index": "windows",
        "query": "winlog.event_data.SubjectDomainName:NTAUTHORI*",
        "category": "windows"
      },
      {
        "index": "ad_logs",
        "query": "ResultType:50126",
        "category": "ad_ldap"
      },
      {
        "index": "app_logs",
        "query": "endpoint:/customer_records.txt",
        "category": "others_application"
      }
    ]
  }
}

Response fields

Field	Type	Description
_id	String	The Id for the new rule.

List all findings and their correlations within a time window

This API provides a list of all findings and their correlations within a specified time window:

GET /_plugins/_security_analytics/correlations?start_timestamp=<start time in milliseconds>&end_timestamp=<end time in milliseconds>

Query parameters

Parameter	Type	Description
start_timestamp	Number	Start time for the time window, in milliseconds.
end_timestamp	Number	End time for the time window, in milliseconds.

Example request

GET /_plugins/_security_analytics/correlations?start_timestamp=1689289210000&end_timestamp=1689300010000

{% include copy-curl.html %}

Example response

{
  "findings": [
    {
      "finding1": "931de5f0-a276-45d5-9cdb-83e1045a3630",
      "logType1": "network",
      "finding2": "1e6f6a12-83f1-4a38-9bb8-648f196859cc",
      "logType2": "test_windows",
      "rules": [
        "nqI2TokBgL5wWFPZ6Gfu"
      ]
    }
  ]
}

Response fields

Field	Type	Description
finding1	String	The Id for a first finding in the correlation.
logType1	String	The log type associated with the first finding.
finding2	String	The Id for a second finding in the correlation.
logType2	String	The log type associated with the second finding.
rules	Array	A list of correlation rule IDs associated with the correlated findings.

List correlations for a finding belonging to a log type

This API is used to list correlations for specific findings and the log types associated with them:

GET /_plugins/_security_analytics/findings/correlate?finding=425dce0b-f5ee-4889-b0c0-7d15669f0871&detector_type=ad_ldap&nearby_findings=20&time_window=10m

Query parameters

Parameter	Type	Description
finding	String	The finding ID.
detector_type	String	The log type for the detector.
nearby_findings	Number	The number of nearby findings with respect to the given finding Id.
time_window	String	Sets a time window in which all of the correlations must have occurred together.

Example request

GET /_plugins/_security_analytics/findings/correlate?finding=425dce0b-f5ee-4889-b0c0-7d15669f0871&detector_type=ad_ldap&nearby_findings=20&time_window=10m

{% include copy-curl.html %}

Example response

{
  "findings": [
    {
      "finding": "5c661104-aaa9-484b-a91f-9cad4ae6d5f5",
      "detector_type": "others_application",
      "score": 0.000015182109564193524
    },
    {
      "finding": "2485b623-6573-42f4-a055-9b927e38a65f",
      "detector_type": "ad_ldap",
      "score": 0.000001615897872397909
    },
    {
      "finding": "051e00ad-5996-4c41-be20-f992451d1331",
      "detector_type": "windows",
      "score": 0.000016230604160227813
    },
    {
      "finding": "f11ca8a3-50d7-4074-a951-51439aa9e67b",
      "detector_type": "s3",
      "score": 0.000001759401811796124
    },
    {
      "finding": "9b86980e-5fb7-4c5a-bd1b-879a1e3baf12",
      "detector_type": "network",
      "score": 0.0000016306962606904563
    },
    {
      "finding": "e7dea5a1-164f-48f9-880e-4ba33e508713",
      "detector_type": "network",
      "score": 0.00001632626481296029
    }
  ]
}

Response fields

Field	Type	Description
finding	String	The finding ID.
detector_type	String	The log type associated with the finding.
score	Number	The correlation score for the correlated finding. The score is based on the proximity of relevant findings in the threat scenario defined by the correlation rule.