Anomalous Single Factor Signin

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

'Detects successful signins using single factor authentication where the device, location, and ASN are abnormal. Single factor authentications pose an opportunity to access compromised accounts, investigate these for anomalous occurrencess. Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-devices#non-compliant-device-sign-in'

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)
Authentications of Privileged Accounts Outside of Expected Controls (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: f7c3f5c8-71ea-49ff-b8b3-148f0e346291
name: Anomalous Single Factor Signin
description: |
  'Detects successful signins using single factor authentication where the device, location, and ASN are abnormal.
   Single factor authentications pose an opportunity to access compromised accounts, investigate these for anomalous occurrencess.
   Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-devices#non-compliant-device-sign-in'
severity: Low
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - SigninLogs
queryFrequency: 1d
queryPeriod: 7d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1078.004
tags:
  - AADSecOpsGuide
query: |
  let known_locations = (SigninLogs
    | where TimeGenerated between(ago(7d)..ago(1d))
    | where ResultType == 0
    | extend LocationDetail = strcat(Location, "-", LocationDetails.state)
    | summarize by LocationDetail);
  let known_asn = (SigninLogs
    | where TimeGenerated between(ago(7d)..ago(1d))
    | where ResultType == 0
    | summarize by AutonomousSystemNumber);
  SigninLogs
  | where TimeGenerated > ago(1d)
  | where ResultType == 0
  | where isempty(DeviceDetail.deviceId)
  | where AuthenticationRequirement == "singleFactorAuthentication"
  | extend LocationParsed = parse_json(LocationDetails), DeviceParsed = parse_json(DeviceDetail)
  | extend City = tostring(LocationParsed.city), State = tostring(LocationParsed.state)
  | extend LocationDetail = strcat(Location, "-", State)
  | extend DeviceId = tostring(DeviceParsed.deviceId), DeviceName=tostring(DeviceParsed.displayName), OS=tostring(DeviceParsed.operatingSystem), Browser=tostring(DeviceParsed.browser)
  | where AutonomousSystemNumber !in (known_asn) and LocationDetail !in (known_locations)
  | project TimeGenerated, Type, UserId, UserDisplayName, UserPrincipalName, IPAddress, Location, State, City, ResultType, ResultDescription, AppId, AppDisplayName, AuthenticationRequirement, ConditionalAccessStatus, ResourceDisplayName, ClientAppUsed, Identity, HomeTenantId, ResourceTenantId, Status, UserAgent, DeviceId, DeviceName, OS, Browser, MfaDetail
  | extend Name = tostring(split(UserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(UserPrincipalName,'@',1)[0])
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: UserPrincipalName
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPAddress
  - entityType: CloudApplication
    fieldMappings:
      - identifier: AppId
        columnName: AppId
      - identifier: Name
        columnName: AppDisplayName
version: 1.0.6
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: Pete Bryan
    support:
        tier: Community
    categories:
        domains: [ "Security - Others" ]

Stages and Predicates

Let binding: `known_locations`

let known_locations = (SigninLogs
  | where TimeGenerated between(ago(7d)..ago(1d))
  | where ResultType == 0
  | extend LocationDetail = strcat(Location, "-", LocationDetails.state)
  | summarize by LocationDetail);

Let binding: `known_asn`

let known_asn = (SigninLogs
  | where TimeGenerated between(ago(7d)..ago(1d))
  | where ResultType == 0
  | summarize by AutonomousSystemNumber);

Stage 1: `source`

SigninLogs

Stage 2: `where`

| where TimeGenerated > ago(1d)

Stage 3: `where`

| where ResultType == 0

Stage 4: `where`

| where isempty(DeviceDetail.deviceId)

Stage 5: `where`

| where AuthenticationRequirement == "singleFactorAuthentication"

Stage 6: `extend` (4 consecutive steps)

| extend LocationParsed = parse_json(LocationDetails), DeviceParsed = parse_json(DeviceDetail)
| extend City = tostring(LocationParsed.city), State = tostring(LocationParsed.state)
| extend LocationDetail = strcat(Location, "-", State)
| extend DeviceId = tostring(DeviceParsed.deviceId), DeviceName=tostring(DeviceParsed.displayName), OS=tostring(DeviceParsed.operatingSystem), Browser=tostring(DeviceParsed.browser)

Stage 7: `where`

| where AutonomousSystemNumber !in (known_asn) and LocationDetail !in (known_locations)

References known_asn, known_locations (defined above).

Stage 8: `project`

| project TimeGenerated, Type, UserId, UserDisplayName, UserPrincipalName, IPAddress, Location, State, City, ResultType, ResultDescription, AppId, AppDisplayName, AuthenticationRequirement, ConditionalAccessStatus, ResourceDisplayName, ClientAppUsed, Identity, HomeTenantId, ResourceTenantId, Status, UserAgent, DeviceId, DeviceName, OS, Browser, MfaDetail

Stage 9: `extend`

| extend Name = tostring(split(UserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(UserPrincipalName,'@',1)[0])

Exclusions

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

Field	Kind	Excluded values
`AutonomousSystemNumber`	eq	`known_asn`
`LocationDetail`	eq	`known_locations`

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
`AuthenticationRequirement`	eq	`singleFactorAuthentication` transforms: `cased`
`ResultType`	eq	`0` transforms: `cased`
`deviceId`	is_null	(no value, null check)

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
`AppDisplayName`	`project`
`AppId`	`project`
`AuthenticationRequirement`	`project`
`Browser`	`project`
`City`	`project`
`ClientAppUsed`	`project`
`ConditionalAccessStatus`	`project`
`DeviceId`	`project`
`DeviceName`	`project`
`HomeTenantId`	`project`
`IPAddress`	`project`
`Identity`	`project`
`Location`	`project`
`MfaDetail`	`project`
`OS`	`project`
`ResourceDisplayName`	`project`
`ResourceTenantId`	`project`
`ResultDescription`	`project`
`ResultType`	`project`
`State`	`project`
`Status`	`project`
`TimeGenerated`	`project`
`Type`	`project`
`UserAgent`	`project`
`UserDisplayName`	`project`
`UserId`	`project`
`UserPrincipalName`	`project`
`Name`	`extend`
`UPNSuffix`	`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)

Anomalous Single Factor Signin

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Let binding: `known_locations`

Let binding: `known_asn`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `where`

Stage 6: `extend` (4 consecutive steps)

Stage 7: `where`

Stage 8: `project`

Stage 9: `extend`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

Anomalous Single Factor Signin

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Let binding: known_locations

Let binding: known_asn

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: where

Stage 6: extend (4 consecutive steps)

Stage 7: where

Stage 8: project

Stage 9: extend

Exclusions

Indicators

Output fields

Let binding: `known_locations`

Let binding: `known_asn`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `where`

Stage 6: `extend` (4 consecutive steps)

Stage 7: `where`

Stage 8: `project`

Stage 9: `extend`