Detection Rules

A detection rule is a query that runs continuously on new logs as they arrive in Scanner. You can create create, read, update, and delete detection rules with the Scanner API.

Create a new detection rule

POST /v1/detection_rule

Create a new detection rule with the specified data.

If the detection rule is active, it will be immediately scheduled for backfill and execution.

Body

Name	Type	Description
tenant_id required	string	Unique identifier for the tenant
name required	string	Name of the detection rule
description required	string	Description of the detection rule
time_range_s required	number	Lookback period (in seconds). Must be minute granuarlity (for example, 60 seconds is valid, but 30 seconds is not).
run_frequency_s required	number	How frequently to run the detection rule (in seconds). Must be minute granularity and <= time_range_s.
enabled required	boolean	Whether the detection rule is enabled
severity required	See Detection severity	The severity of the detection
query_text required	string	Query for the detection rule
event_sink_ids required	list of strings	Event sinks to send event alerts to
tags	list of strings	Associated tags for the detection rule. Scanner has default MITRE Tags that you can use or you can create your own.
sync_key	string	Sync key, used by automatic detection rule syncers

Example

curl $API_BASE/v1/detection_rule \
-H "Authorization: Bearer $SCANNER_API_KEY" \
-H "Content-Type: application/json" \
-X POST \
-d '{
    "tenant_id": "00000000-0000-0000-0000-000000000000",
    "name": "Errors",
    "description": "Errors in application logs",
    "time_range_s": 300,
    "run_frequency_s": 300,
    "enabled": true,
    "severity": "Informational",
    "query_text": "error | count | where @q.count > 100",
    "tags": ["scanner.error"],
    "event_sink_ids": []
}'

Response

Returns the newly created detection rule.

{
  "detection_rule": {
    "id": "d87284f8-b0f3-4464-9ba9-258c0e585d09",
    "sync_key": null,
    "prepared_query_id": "b8aa9bb6-de1e-4ef8-82bb-29974a1e4ff2",
    "detection_rule_sync_id": null,
    "query_text": "error | count | where @q.count > 100",
    "tenant_id": "00000000-0000-0000-0000-000000000000",
    "time_range_s": 300,
    "run_frequency_s": 300,
    "debounce": true,
    "author_user_id": null,
    "name": "Errors",
    "description": "Errors in application logs",
    "enabled": true,
    "enabled_override": null,
    "severity": "Informational",
    "alert_template": null,
    "tags":["scanner.error"],
    "created_at": "2024-05-09T01:07:24Z",
    "updated_at": "2024-05-09T01:07:24Z",
    "event_sink_ids": [],
    "last_alerted_at": null
  }
}

List detection rules

GET /v1/detection_rule

List all detection rules for a tenant.

Query parameters

Name	Type	Description
tenant_id required	string	Unique identifier for the tenant
pagination[page_size]	number	Maximum number of results to return in a page. Defaults to 50
pagination[page_token]	string	Cursor for pagination. list_detection_rulesreturns next_page_token to be used for this field. If the field is not specified, paging will start at the beginning of the list.

Example

curl -G $API_BASE/v1/detection_rule \
--data-urlencode "tenant_id=00000000-0000-0000-0000-000000000001" \
--data-urlencode "pagination[page_size]=5" \
--data-urlencode "pagination[page_token]=1" \
-H "Authorization: Bearer $SCANNER_API_KEY" \
-H "Content-Type: application/json"

Response

Returns a list of detection rule summaries and pagination information. The detection rule summary object is the same as the detection rule object, but it does not include event_sink_ids. The pagination information includes the next_page_tokento use as the pagination cursor. next_page_tokenis null if there are no more remaining pages.

{
  "data": {
    "detection_rules": [
      {
        "id": "d87284f8-b0f3-4464-9ba9-258c0e585d09",
        "sync_key": null,
        "prepared_query_id": "b8aa9bb6-de1e-4ef8-82bb-29974a1e4ff2",
        "detection_rule_sync_id": null,
        "query_text": "error | count | where @q.count > 100",
        "tenant_id": "00000000-0000-0000-0000-000000000000",
        "time_range_s": 300,
        "run_frequency_s": 300,
        "debounce": true,
        "author_user_id": null,
        "name": "Errors",
        "description": "Errors in application logs",
        "enabled": true,
        "enabled_override": null,
        "severity": "Informational",
        "alert_template": null,
        "tags":["scanner.error"],
        "created_at": "2024-05-09T01:07:24Z",
        "updated_at": "2024-05-09T01:07:24Z",
        "last_alerted_at": null
      }
    ]
  },
  "pagination": {
    "next_page_token": null
  }
}

Get a detection rule

GET /v1/detection_rule/{id}

Get the detection rule with the given id.

Example

curl $API_BASE/v1/detection_rule/d87284f8-b0f3-4464-9ba9-258c0e585d09 \
-H "Authorization: Bearer $SCANNER_API_KEY" \
-H "Content-Type: application/json" \
-X GET

Response

Returns the detection rule.

{
  "detection_rule": {
    "id": "d87284f8-b0f3-4464-9ba9-258c0e585d09",
    "sync_key": null,
    "prepared_query_id": "b8aa9bb6-de1e-4ef8-82bb-29974a1e4ff2",
    "detection_rule_sync_id": null,
    "query_text": "error | count | where @q.count > 100",
    "tenant_id": "00000000-0000-0000-0000-000000000000",
    "time_range_s": 300,
    "run_frequency_s": 300,
    "debounce": true,
    "author_user_id": null,
    "name": "Errors",
    "description": "Errors in application logs",
    "enabled": true,
    "enabled_override": null,
    "severity": "Informational",
    "alert_template": null,
    "tags":["scanner.error"],
    "created_at": "2024-05-09T01:07:24Z",
    "updated_at": "2024-05-09T01:07:24Z",
    "event_sink_ids": [],
    "last_alerted_at": null
  }
}

Update a detection rule

PUT /v1/detection_rule/{id}

Update the detection rule with the given id. If the rule is synced from GitHub (in which case detection_rule_sync_id will be non-null), then enable_override is the only field that can be updated.

Body

Name	Type	Description
id required	string	Unique identifier for the detection rule
name	string	Update the name of the detection rule
description	string	Update the description of the detection rule
time_range_s	number	Update the lookback period (in seconds) of the detection rule. Must be minute granularity (for example, 60 seconds is valid, but 30 seconds is not).
run_frequency_s	number	Update the how frequently the detection rule is run (in seconds). Must be minute granularity and <= time_range_s.
enabled	boolean	Enable or disable the detection rule
enabled_override	boolean or null	Enable or disable a synced detection rule, overrides enabled if non-null (can only be used on synced detection rules, where detection_rule_sync_id is non-null).
severity	See Detection severity	Update the severity of the detection rule
query_text	string	Update the query for the detection rule
tags	list of strings	Update the tags for the detection rule. Scanner has default MITRE Tags that you can use or you can create your own.
event_sink_ids	list of strings	Update the event sinks for the detection rule
sync_key	string	Update the sync key for the detection rule

Example

curl $API_BASE/v1/detection_rule/d87284f8-b0f3-4464-9ba9-258c0e585d09 \
-H "Authorization: Bearer $SCANNER_API_KEY" \
-H "Content-Type: application/json" \
-X PUT \
-d '{
    "id": "d87284f8-b0f3-4464-9ba9-258c0e585d09",
    "description": "Detect errors in application logs"
}'

Response

Returns the updated detection rule.

{
  "detection_rule": {
    "id": "d87284f8-b0f3-4464-9ba9-258c0e585d09",
    "sync_key": null,
    "prepared_query_id": "b8aa9bb6-de1e-4ef8-82bb-29974a1e4ff2",
    "detection_rule_sync_id": null,
    "query_text": "error | count | where @q.count > 100",
    "tenant_id": "00000000-0000-0000-0000-000000000000",
    "time_range_s": 300,
    "run_frequency_s": 300,
    "debounce": true,
    "author_user_id": null,
    "name": "Errors",
    "description": "Detect errors in application logs",
    "enabled": true,
    "enabled_override": null,
    "severity": "Informational",
    "alert_template": null,
    "tags":["scanner.error"],
    "created_at": "2024-05-09T01:07:24Z",
    "updated_at": "2024-05-09T01:07:24Z",
    "event_sink_ids": [],
    "last_alerted_at": null
  }
}

Delete a detection rule

DELETE /v1/detection_rule/{id}

Delete the detection rule with the given id.

Example

curl $API_BASE/v1/detection_rule/123e4567-e89b-12d3-a456-426614174000 \
-H "Authorization: Bearer $SCANNER_API_KEY" \
-H "Content-Type: application/json" \
-X DELETE

Response

Returns the id and tenant_id for the deleted detection rule.

{
  "id": "d87284f8-b0f3-4464-9ba9-258c0e585d09",
  "tenant_id": "00000000-0000-0000-0000-000000000000"
}

Detection severity

We use the OCSF schema for detection severity:

• Unknown

• Information

• Low

• Medium

• High

• Critical

• Fatal

• Other

The detection severity must be one of these string values, e.g.

"severity": "Critical"