Authentications of Privileged Accounts Outside of Expected Controls

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Id	af435ca1-fb70-4de1-92c1-7435c48482a9
Rulename	Authentications of Privileged Accounts Outside of Expected Controls
Description	Detects when a privileged user account successfully authenticates from a location, device or ASN that another admin has not logged in from in the last 7 days. Privileged accounts are a key target for threat actors, monitoring for logins from these accounts that deviate from normal activity can help identify compromised accounts. Authentication attempts should be investigated to ensure the activity was legitimate and if there is other similar activity. Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-successful-unusual-sign-ins
Severity	Medium
Tactics	InitialAccess
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/AuthenticationsofPrivilegedAccountsOutsideofExpectedControls.yaml
Version	1.0.2
Arm template	af435ca1-fb70-4de1-92c1-7435c48482a9.json

KQL

let admin_users = (IdentityInfo
  | summarize arg_max(TimeGenerated, *) by AccountUPN
  | where AssignedRoles contains "admin"
  | summarize by tolower(AccountUPN));
  let admin_asn = (SigninLogs
  | where TimeGenerated between (ago(7d)..ago(1d))
  | where tolower(UserPrincipalName) in (admin_users)
  | summarize by AutonomousSystemNumber);
  let admin_locations = (SigninLogs
  | where TimeGenerated between (ago(7d)..ago(1d))
  | where tolower(UserPrincipalName) in (admin_users)
  | summarize by Location);
  let admin_devices = (SigninLogs
  | where TimeGenerated between (ago(7d)..ago(1d))
  | where tolower(UserPrincipalName) in (admin_users)
  | extend deviceId = tostring(DeviceDetail.deviceId)
  | where isnotempty(deviceId)
  | summarize by deviceId);
  SigninLogs
  | where TimeGenerated > ago(1d)
  | where ResultType == 0
  | where tolower(UserPrincipalName) in (admin_users)
  | extend deviceId = tostring(DeviceDetail.deviceId)
  | where AutonomousSystemNumber !in (admin_asn) and deviceId !in (admin_devices) and Location !in (admin_locations)

YAML

description: |
  'Detects when a privileged user account successfully authenticates from a location, device or ASN that another admin has not logged in from in the last 7 days.
    Privileged accounts are a key target for threat actors, monitoring for logins from these accounts that deviate from normal activity can help identify compromised accounts.
    Authentication attempts should be investigated to ensure the activity was legitimate and if there is other similar activity.
    Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-successful-unusual-sign-ins'  
tactics:
- InitialAccess
version: 1.0.2
metadata:
  source:
    kind: Community
  support:
    tier: Community
  author:
    name: Pete Bryan
  categories:
    domains:
    - Security - Others
    - Identity
severity: Medium
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SigninLogs/AuthenticationsofPrivilegedAccountsOutsideofExpectedControls.yaml
queryPeriod: 7d
id: af435ca1-fb70-4de1-92c1-7435c48482a9
tags:
- AADSecOpsGuide
triggerOperator: gt
requiredDataConnectors:
- dataTypes:
  - SigninLogs
  connectorId: AzureActiveDirectory
- dataTypes:
  - BehaviorAnalytics
  connectorId: BehaviorAnalytics
- dataTypes:
  - IdentityInfo
  connectorId: BehaviorAnalytics
triggerThreshold: 0
name: Authentications of Privileged Accounts Outside of Expected Controls
kind: Scheduled
relevantTechniques:
- T1078.004
query: |
  let admin_users = (IdentityInfo
    | summarize arg_max(TimeGenerated, *) by AccountUPN
    | where AssignedRoles contains "admin"
    | summarize by tolower(AccountUPN));
    let admin_asn = (SigninLogs
    | where TimeGenerated between (ago(7d)..ago(1d))
    | where tolower(UserPrincipalName) in (admin_users)
    | summarize by AutonomousSystemNumber);
    let admin_locations = (SigninLogs
    | where TimeGenerated between (ago(7d)..ago(1d))
    | where tolower(UserPrincipalName) in (admin_users)
    | summarize by Location);
    let admin_devices = (SigninLogs
    | where TimeGenerated between (ago(7d)..ago(1d))
    | where tolower(UserPrincipalName) in (admin_users)
    | extend deviceId = tostring(DeviceDetail.deviceId)
    | where isnotempty(deviceId)
    | summarize by deviceId);
    SigninLogs
    | where TimeGenerated > ago(1d)
    | where ResultType == 0
    | where tolower(UserPrincipalName) in (admin_users)
    | extend deviceId = tostring(DeviceDetail.deviceId)
    | where AutonomousSystemNumber !in (admin_asn) and deviceId !in (admin_devices) and Location !in (admin_locations)  
entityMappings:
- fieldMappings:
  - columnName: UserPrincipalName
    identifier: FullName
  entityType: Account
queryFrequency: 1d

ARM