Vectra AI Detect - Suspicious Behaviors by Category

// 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"]);
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 triaged = DeviceCustomString5
| where triaged != "True"
| project-rename vectra_URL = DeviceCustomString4
| project-rename detection_name = DeviceEventClassID
| extend Tactic = case( Category == "COMMAND & CONTROL", "CommandAndControl",
                        Category == "BOTNET ACTIVITY" , "Impact",
                        Category == "EXFILTRATION", "Exfiltration",
                        Category == "LATERAL MOVEMENT", "LateralMovement",
                        Category == "RECONNAISSANCE", "Discovery",
                        "UNKNOWN")
| extend level = case( threat_score <  50 and certainty_score < 50, "Low",
                       threat_score < 50 and certainty_score >= 50 , "Medium", 
                       threat_score >= 50 and certainty_score <= 50, "High", 
                       threat_score >= 50 and certainty_score >= 50, "Critical",
                       "UNKNOWN")
| extend Severity = case(level == "Info", "Informational",level == "Critical", "High", level)
| extend account = extract("account=(.+?);", 1, AdditionalExtensions)
| extend upn = iff(account matches regex ":", tostring(split(account,":")[1]) ,tostring(split(account,":")[0]))
| extend name = tostring(split(upn, "@")[0])
| extend upn_suffix = tostring(split(upn, "@")[1])
| extend source_entity = case(level == "Info", "Informational",level == "Critical", "High", level)
| where Category in (configured_tactics) 
| summarize arg_max(threat_score, *) by source_entity , Activity
| sort by TimeGenerated

tactics:
- CredentialAccess
- Discovery
- LateralMovement
- Collection
- CommandAndControl
- Exfiltration
- Impact
eventGroupingSettings:
  aggregationKind: AlertPerResult
requiredDataConnectors:
- dataTypes:
  - CommonSecurityLog
  connectorId: CefAma
name: Vectra AI Detect - Suspicious Behaviors by Category
alertDetailsOverride:
  alertDynamicProperties:
  - value: vectra_URL
    alertProperty: AlertLink
  - value: DeviceProduct
    alertProperty: ProductName
  - value: DeviceVendor
    alertProperty: ProviderName
  - value: certainty_score
    alertProperty: ConfidenceScore
  alertSeverityColumnName: Severity
  alertDisplayNameFormat: Vectra AI Detect - {{Activity}} detected
  alertDescriptionFormat: Source entity is {{source_entity}} and category is {{Category}}. Threat score is {{threat_score}}.
kind: Scheduled
queryPeriod: 5m
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"]);
  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 triaged = DeviceCustomString5
  | where triaged != "True"
  | project-rename vectra_URL = DeviceCustomString4
  | project-rename detection_name = DeviceEventClassID
  | extend Tactic = case( Category == "COMMAND & CONTROL", "CommandAndControl",
                          Category == "BOTNET ACTIVITY" , "Impact",
                          Category == "EXFILTRATION", "Exfiltration",
                          Category == "LATERAL MOVEMENT", "LateralMovement",
                          Category == "RECONNAISSANCE", "Discovery",
                          "UNKNOWN")
  | extend level = case( threat_score <  50 and certainty_score < 50, "Low",
                         threat_score < 50 and certainty_score >= 50 , "Medium", 
                         threat_score >= 50 and certainty_score <= 50, "High", 
                         threat_score >= 50 and certainty_score >= 50, "Critical",
                         "UNKNOWN")
  | extend Severity = case(level == "Info", "Informational",level == "Critical", "High", level)
  | extend account = extract("account=(.+?);", 1, AdditionalExtensions)
  | extend upn = iff(account matches regex ":", tostring(split(account,":")[1]) ,tostring(split(account,":")[0]))
  | extend name = tostring(split(upn, "@")[0])
  | extend upn_suffix = tostring(split(upn, "@")[1])
  | extend source_entity = case(level == "Info", "Informational",level == "Critical", "High", level)
  | where Category in (configured_tactics) 
  | summarize arg_max(threat_score, *) by source_entity , Activity
  | sort by TimeGenerated  
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Vectra AI Detect/Analytic Rules/VectraDetect-Suspected-Behavior-by-Tactics.yaml
triggerThreshold: 0
description: |
  'Create an incident for each new malicious behavior detected by Vectra Detect for a specific Category. 
  By default, it looks through all tactics. This can be modified to create incident only for a subset of tactics.'  
version: 1.1.1
status: Available
queryFrequency: 5m
severity: Informational
entityMappings:
- entityType: Host
  fieldMappings:
  - identifier: HostName
    columnName: SourceHostName
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: name
  - identifier: UPNSuffix
    columnName: upn_suffix
triggerOperator: gt
id: 6cb75f65-231f-46c4-a0b3-50ff21ee6ed3
relevantTechniques:
- T1003
- T1087
- T1021
- T1119
- T1071
- T1041
- T1499
customDetails:
  AttackCategory: Category
  AttackType: Activity