Vectra AI Detect - Detections with High Severity

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Id	39e48890-2c02-487e-aa9e-3ba494061798
Rulename	Vectra AI Detect - Detections with High Severity
Description	Create an incident for high severity malicious behavior detected by Vectra AI (Threat score superior to 7.0). The Severity is a mapping with the Threat score assigned to a detection. It ranges between 0 and 10. The severity_threshold variable can be adjusted as desired.'
Severity	High
Tactics	CredentialAccess Discovery LateralMovement Collection CommandAndControl Exfiltration Impact
Required data connectors	AIVectraDetect
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Vectra AI Detect/Analytic Rules/VectraDetect-HighSeverityDetection-by-Tactics.yaml
Version	1.0.4
Arm template	39e48890-2c02-487e-aa9e-3ba494061798.json

KQL

// Edit this variable to only keep the tactics where an incident needs to be created (Defaults are: "COMMAND & CONTROL", "BOTNET ACTIVITY", "EXFILTRATION", "LATERAL MOVEMENT", "RECONNAISSANCE")   
let configured_tactics = dynamic(["COMMAND & CONTROL", "BOTNET ACTIVITY", "EXFILTRATION", "LATERAL MOVEMENT", "RECONNAISSANCE"]);
//default threshold is 7 (meaning a threat score of 70)
let severity_threshold = 7.0;
//Map by default to High Severity in Sentinel
let Severity = "High";
CommonSecurityLog
| where DeviceVendor == "Vectra Networks"
| where DeviceProduct == "X Series"
| where DeviceEventClassID != "campaigns" and DeviceEventClassID != "hsc" and DeviceEventClassID != "audit" and DeviceEventClassID != "health" and DeviceEventClassID != "asc"
| extend Category = coalesce(
                          column_ifexists("DeviceEventCategory", ""), 
                          extract("cat=(.+?)(;|$)", 1, AdditionalExtensions), 
                          ""
                      )
| project-rename threat_score = FlexNumber1
| project-rename certainty_score = FlexNumber2
| project-rename vectra_URL = DeviceCustomString4
| project-rename detection_name = DeviceEventClassID
| where todecimal(LogSeverity) >= severity_threshold
| extend Tactic = case( Category == "COMMAND & CONTROL", "CommandAndControl",
                        Category == "BOTNET ACTIVITY" , "Impact",
                        Category == "EXFILTRATION", "Exfiltration",
                        Category == "LATERAL MOVEMENT", "LateralMovement",
                        Category == "RECONNAISSANCE", "Discovery",
                        "UNKNOWN")
| extend account = extract("account=(.+?);", 1, AdditionalExtensions)
| extend upn = iff(account matches regex ":", tostring(split(account,":")[1]) ,tostring(split(account,":")[0])) 
| extend source_entity = case( isnotempty(upn), upn,
                               isnotempty(SourceHostName), SourceHostName,
                               "UNKNWON") 
| where Category in (configured_tactics) 
| summarize arg_max(threat_score, *) by source_entity, Activity
| sort by TimeGenerated
| project TimeGenerated, source_entity, SourceHostName, SourceIP, upn, Tactic, Activity, LogSeverity, Severity, vectra_URL
| extend AccountCustomEntity = upn, HostCustomEntity = SourceHostName, IPCustomEntity = SourceIP, timestamp = TimeGenerated

YAML

severity: High
triggerThreshold: 0
query: |
  // Edit this variable to only keep the tactics where an incident needs to be created (Defaults are: "COMMAND & CONTROL", "BOTNET ACTIVITY", "EXFILTRATION", "LATERAL MOVEMENT", "RECONNAISSANCE")   
  let configured_tactics = dynamic(["COMMAND & CONTROL", "BOTNET ACTIVITY", "EXFILTRATION", "LATERAL MOVEMENT", "RECONNAISSANCE"]);
  //default threshold is 7 (meaning a threat score of 70)
  let severity_threshold = 7.0;
  //Map by default to High Severity in Sentinel
  let Severity = "High";
  CommonSecurityLog
  | where DeviceVendor == "Vectra Networks"
  | where DeviceProduct == "X Series"
  | where DeviceEventClassID != "campaigns" and DeviceEventClassID != "hsc" and DeviceEventClassID != "audit" and DeviceEventClassID != "health" and DeviceEventClassID != "asc"
  | extend Category = coalesce(
                            column_ifexists("DeviceEventCategory", ""), 
                            extract("cat=(.+?)(;|$)", 1, AdditionalExtensions), 
                            ""
                        )
  | project-rename threat_score = FlexNumber1
  | project-rename certainty_score = FlexNumber2
  | project-rename vectra_URL = DeviceCustomString4
  | project-rename detection_name = DeviceEventClassID
  | where todecimal(LogSeverity) >= severity_threshold
  | extend Tactic = case( Category == "COMMAND & CONTROL", "CommandAndControl",
                          Category == "BOTNET ACTIVITY" , "Impact",
                          Category == "EXFILTRATION", "Exfiltration",
                          Category == "LATERAL MOVEMENT", "LateralMovement",
                          Category == "RECONNAISSANCE", "Discovery",
                          "UNKNOWN")
  | extend account = extract("account=(.+?);", 1, AdditionalExtensions)
  | extend upn = iff(account matches regex ":", tostring(split(account,":")[1]) ,tostring(split(account,":")[0])) 
  | extend source_entity = case( isnotempty(upn), upn,
                                 isnotempty(SourceHostName), SourceHostName,
                                 "UNKNWON") 
  | where Category in (configured_tactics) 
  | summarize arg_max(threat_score, *) by source_entity, Activity
  | sort by TimeGenerated
  | project TimeGenerated, source_entity, SourceHostName, SourceIP, upn, Tactic, Activity, LogSeverity, Severity, vectra_URL
  | extend AccountCustomEntity = upn, HostCustomEntity = SourceHostName, IPCustomEntity = SourceIP, timestamp = TimeGenerated  
queryFrequency: 1h
requiredDataConnectors:
- connectorId: AIVectraDetect
  dataTypes:
  - CommonSecurityLog
id: 39e48890-2c02-487e-aa9e-3ba494061798
version: 1.0.4
name: Vectra AI Detect - Detections with High Severity
kind: Scheduled
status: Available
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Vectra AI Detect/Analytic Rules/VectraDetect-HighSeverityDetection-by-Tactics.yaml
queryPeriod: 1h
relevantTechniques: 
triggerOperator: gt
tactics:
- CredentialAccess
- Discovery
- LateralMovement
- Collection
- CommandAndControl
- Exfiltration
- Impact
alertDetailsOverride:
  alertSeverityColumnName: Severity
  alertDescriptionFormat: Malicious behavior {{Activity}} has been detected for entity {{source_entity}}. Pivot to Detect UI with {{vectra_URL}}
  alertTacticsColumnName: Tactic
  alertDisplayNameFormat: Vectra AI Detect - High Severity behavior for {{source_entity}}
description: |
  'Create an incident for high severity malicious behavior detected by Vectra AI (Threat score superior to 7.0). 
  The Severity is a mapping with the Threat score assigned to a detection. It ranges between 0 and 10. 
  The severity_threshold variable can be adjusted as desired.'   
entityMappings:
- entityType: Host
  fieldMappings:
  - identifier: HostName
    columnName: HostCustomEntity
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: IPCustomEntity
- entityType: Account
  fieldMappings:
  - identifier: FullName
    columnName: AccountCustomEntity

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/39e48890-2c02-487e-aa9e-3ba494061798')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/39e48890-2c02-487e-aa9e-3ba494061798')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "Vectra AI Detect - Detections with High Severity",
        "description": "'Create an incident for high severity malicious behavior detected by Vectra AI (Threat score superior to 7.0). \nThe Severity is a mapping with the Threat score assigned to a detection. It ranges between 0 and 10. \nThe severity_threshold variable can be adjusted as desired.' \n",
        "severity": "High",
        "enabled": true,
        "query": "// Edit this variable to only keep the tactics where an incident needs to be created (Defaults are: \"COMMAND & CONTROL\", \"BOTNET ACTIVITY\", \"EXFILTRATION\", \"LATERAL MOVEMENT\", \"RECONNAISSANCE\")   \nlet configured_tactics = dynamic([\"COMMAND & CONTROL\", \"BOTNET ACTIVITY\", \"EXFILTRATION\", \"LATERAL MOVEMENT\", \"RECONNAISSANCE\"]);\n//default threshold is 7 (meaning a threat score of 70)\nlet severity_threshold = 7.0;\n//Map by default to High Severity in Sentinel\nlet Severity = \"High\";\nCommonSecurityLog\n| where DeviceVendor == \"Vectra Networks\"\n| where DeviceProduct == \"X Series\"\n| where DeviceEventClassID != \"campaigns\" and DeviceEventClassID != \"hsc\" and DeviceEventClassID != \"audit\" and DeviceEventClassID != \"health\" and DeviceEventClassID != \"asc\"\n| extend Category = coalesce(\n                          column_ifexists(\"DeviceEventCategory\", \"\"), \n                          extract(\"cat=(.+?)(;|$)\", 1, AdditionalExtensions), \n                          \"\"\n                      )\n| project-rename threat_score = FlexNumber1\n| project-rename certainty_score = FlexNumber2\n| project-rename vectra_URL = DeviceCustomString4\n| project-rename detection_name = DeviceEventClassID\n| where todecimal(LogSeverity) >= severity_threshold\n| extend Tactic = case( Category == \"COMMAND & CONTROL\", \"CommandAndControl\",\n                        Category == \"BOTNET ACTIVITY\" , \"Impact\",\n                        Category == \"EXFILTRATION\", \"Exfiltration\",\n                        Category == \"LATERAL MOVEMENT\", \"LateralMovement\",\n                        Category == \"RECONNAISSANCE\", \"Discovery\",\n                        \"UNKNOWN\")\n| extend account = extract(\"account=(.+?);\", 1, AdditionalExtensions)\n| extend upn = iff(account matches regex \":\", tostring(split(account,\":\")[1]) ,tostring(split(account,\":\")[0])) \n| extend source_entity = case( isnotempty(upn), upn,\n                               isnotempty(SourceHostName), SourceHostName,\n                               \"UNKNWON\") \n| where Category in (configured_tactics) \n| summarize arg_max(threat_score, *) by source_entity, Activity\n| sort by TimeGenerated\n| project TimeGenerated, source_entity, SourceHostName, SourceIP, upn, Tactic, Activity, LogSeverity, Severity, vectra_URL\n| extend AccountCustomEntity = upn, HostCustomEntity = SourceHostName, IPCustomEntity = SourceIP, timestamp = TimeGenerated\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess",
          "Discovery",
          "LateralMovement",
          "Collection",
          "CommandAndControl",
          "Exfiltration",
          "Impact"
        ],
        "techniques": null,
        "alertRuleTemplateName": "39e48890-2c02-487e-aa9e-3ba494061798",
        "alertDetailsOverride": {
          "alertDisplayNameFormat": "Vectra AI Detect - High Severity behavior for {{source_entity}}",
          "alertSeverityColumnName": "Severity",
          "alertTacticsColumnName": "Tactic",
          "alertDescriptionFormat": "Malicious behavior {{Activity}} has been detected for entity {{source_entity}}. Pivot to Detect UI with {{vectra_URL}}"
        },
        "customDetails": null,
        "entityMappings": [
          {
            "fieldMappings": [
              {
                "columnName": "HostCustomEntity",
                "identifier": "HostName"
              }
            ],
            "entityType": "Host"
          },
          {
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ],
            "entityType": "IP"
          },
          {
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "FullName"
              }
            ],
            "entityType": "Account"
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Vectra AI Detect/Analytic Rules/VectraDetect-HighSeverityDetection-by-Tactics.yaml",
        "templateVersion": "1.0.4",
        "status": "Available"
      }
    }
  ]
}