Privileged User Logon from new ASN

id: 55073036-bb86-47d3-a85a-b113ac3d9396
name: Privileged User Logon from new ASN
description: |
  'Detects a successful logon by a privileged account from an ASN not logged in from in the last 14 days.
    Monitor these logons to ensure they are legitimate and identify if there are any similar sign ins.'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - SigninLogs
  - connectorId: BehaviorAnalytics
    dataTypes:
      - BehaviorAnalytics
  - connectorId: BehaviorAnalytics
    dataTypes:
      - IdentityInfo
queryFrequency: 1d
queryPeriod: 7d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - DefenseEvasion
relevantTechniques:
  - T1078.004
tags:
  - AADSecOpsGuide
query: |
  let admins=(IdentityInfo
    | where AssignedRoles contains "admin" or GroupMembership has "Admin"
    | summarize by tolower(AccountUPN));
    let known_asns = (
    SigninLogs
    | where TimeGenerated between(ago(14d)..ago(1d))
    | where ResultType == 0
    | summarize by AutonomousSystemNumber);
    SigninLogs
    | where TimeGenerated > ago(1d)
    | where ResultType == 0
    | where tolower(UserPrincipalName) in (admins)
    | where AutonomousSystemNumber !in (known_asns)
    | project-reorder TimeGenerated, UserPrincipalName, UserAgent, IPAddress, AutonomousSystemNumber
    | extend AccountName = tostring(split(UserPrincipalName, "@")[0]), AccountUPNSuffix = tostring(split(UserPrincipalName, "@")[1])
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: UserPrincipalName
      - identifier: Name
        columnName: AccountName
      - identifier: UPNSuffix
        columnName: AccountUPNSuffix
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPAddress
version: 1.0.6
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: Microsoft Security Research
    support:
        tier: Community
    categories:
        domains: [ "Identity", "Security - Others" ]