Privileged User Logon from new ASN

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Id	55073036-bb86-47d3-a85a-b113ac3d9396
Rulename	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
Tactics	DefenseEvasion
Techniques	T1078.004
Required data connectors	AzureActiveDirectory BehaviorAnalytics
Kind	Scheduled
Query frequency	1d
Query period	7d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SigninLogs/PrivilegedUserLogonfromnewASN.yaml
Version	1.0.6
Arm template	55073036-bb86-47d3-a85a-b113ac3d9396.json

KQL

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])

YAML

id: 55073036-bb86-47d3-a85a-b113ac3d9396
tags:
- AADSecOpsGuide
triggerOperator: gt
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SigninLogs/PrivilegedUserLogonfromnewASN.yaml
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: UserPrincipalName
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: IPAddress
  entityType: IP
requiredDataConnectors:
- dataTypes:
  - SigninLogs
  connectorId: AzureActiveDirectory
- dataTypes:
  - BehaviorAnalytics
  connectorId: BehaviorAnalytics
- dataTypes:
  - IdentityInfo
  connectorId: BehaviorAnalytics
queryFrequency: 1d
metadata:
  categories:
    domains:
    - Identity
    - Security - Others
  support:
    tier: Community
  source:
    kind: Community
  author:
    name: Microsoft Security Research
queryPeriod: 7d
triggerThreshold: 0
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])  
name: Privileged User Logon from new ASN
kind: Scheduled
tactics:
- DefenseEvasion
severity: Medium
relevantTechniques:
- T1078.004
version: 1.0.6
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.'

ARM