Authentications of Privileged Accounts Outside of Expected Controls

Severity: medium
Time window: 7d
Author: Pete Bryan
Source: github.com/Azure/Azure-Sentinel

'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'

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1078.004` Valid Accounts: Cloud Accounts

Rules detecting the same action

Other rules on this platform that filter on the same API call or operation.

Anomalous sign-in location by user account and authenticating application (Kusto)
Anomalous Single Factor Signin (Kusto)
Azure Many Failed SignIns (Panther)
Azure Portal sign in from another Azure Tenant (Kusto)
Azure Service Principal Sign-In Followed by Arc Cluster Credential Access (Elastic)
Azure SignIn via Legacy Authentication Protocol (Panther)
Detect non-admin requesting token for admin applications (Kusto)
Discovery Using AzureHound (Sigma)

Rule body kusto

id: af435ca1-fb70-4de1-92c1-7435c48482a9
name: 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
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - SigninLogs
  - connectorId: BehaviorAnalytics
    dataTypes:
      - BehaviorAnalytics
  - connectorId: BehaviorAnalytics
    dataTypes:
      - IdentityInfo
queryFrequency: 1d
queryPeriod: 7d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1078.004
tags:
  - AADSecOpsGuide
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:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: UserPrincipalName
version: 1.0.2
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: Pete Bryan
    support:
        tier: Community
    categories:
        domains: [ "Security - Others", "Identity" ]

Stages and Predicates

Let binding: `admin_users`

let admin_users = (IdentityInfo
  | summarize arg_max(TimeGenerated, *) by AccountUPN
  | where AssignedRoles contains "admin"
  | summarize by tolower(AccountUPN));

Let binding: `admin_asn`

let admin_asn = (SigninLogs
  | where TimeGenerated between (ago(7d)..ago(1d))
  | where tolower(UserPrincipalName) in (admin_users)
  | summarize by AutonomousSystemNumber);

Derived from admin_users.

Let binding: `admin_locations`

let admin_locations = (SigninLogs
  | where TimeGenerated between (ago(7d)..ago(1d))
  | where tolower(UserPrincipalName) in (admin_users)
  | summarize by Location);

Derived from admin_users.

Let binding: `admin_devices`

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);

Derived from admin_users.

Stage 1: `source`

SigninLogs

Stage 2: `where`

| where TimeGenerated > ago(1d)

Stage 3: `where`

| where ResultType == 0

Stage 4: `where`

| where tolower(UserPrincipalName) in (admin_users)

References admin_users (defined above).

Stage 5: `extend`

| extend deviceId = tostring(DeviceDetail.deviceId)

Stage 6: `where`

| where AutonomousSystemNumber !in (admin_asn) and deviceId !in (admin_devices) and Location !in (admin_locations)

References admin_asn, admin_devices, admin_locations (defined above).

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`AutonomousSystemNumber`	eq	`admin_asn`
`Location`	eq	`admin_locations`
`deviceId`	eq	`admin_devices`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`ResultType`	eq	`0` transforms: `cased`
`UserPrincipalName`	in	`admin_users` transforms: `tolower`, `cased`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`deviceId`	`extend`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

Authentications of Privileged Accounts Outside of Expected Controls

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Let binding: `admin_users`

Let binding: `admin_asn`

Let binding: `admin_locations`

Let binding: `admin_devices`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `extend`

Stage 6: `where`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

Authentications of Privileged Accounts Outside of Expected Controls

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Let binding: admin_users

Let binding: admin_asn

Let binding: admin_locations

Let binding: admin_devices

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: extend

Stage 6: where

Exclusions

Indicators

Output fields

Let binding: `admin_users`

Let binding: `admin_asn`

Let binding: `admin_locations`

Let binding: `admin_devices`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `extend`

Stage 6: `where`