Detection rules › Kusto

Cisco Duo - Unexpected authentication factor

Status
available
Severity
medium
Time window
1h
Source
github.com/Azure/Azure-Sentinel

'Detects when unexpected authentication factor used.'

MITRE ATT&CK coverage

TacticTechniques
Initial Access

Rule body

id: 16c91a2c-17ad-4985-a9ad-4a4f1cb11830
name: Cisco Duo - Unexpected authentication factor
description: |
  'Detects when unexpected authentication factor used.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: CiscoDuoAuthConnectorDefinition
    dataTypes:
      - DuoAuthentication_CL
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1078
query: |
  let allowed_auth_f = dynamic(['duo_push', 'duo_mobile_passcode']);
  DuoAuthentication_CL
  | where Result =~ 'success'
  | where Factor !in~ (allowed_auth_f)
  | extend IPCustomEntity = AccessDeviceIp, AccountCustomEntity = UserName
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountCustomEntity
version: 1.0.1
kind: Scheduled

Stages and Predicates

Parameters

let allowed_auth_f = dynamic(['duo_push', 'duo_mobile_passcode']);

Stage 1: source

DuoAuthentication_CL

Stage 2: where

| where Result =~ 'success'

Stage 3: where

| where Factor !in~ (allowed_auth_f)

Stage 4: extend

| extend IPCustomEntity = AccessDeviceIp, AccountCustomEntity = UserName

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
Factorinduo_mobile_passcode, duo_pushexcludes:Factor field:"Factor" value:"duo_mobile_passcode" field:"Factor" value:"duo_push"

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Resulteq
  • success
field:"Result" kind:eq value:"success"

Output fields

These fields are emitted when the rule matches.

FieldSource
AccountCustomEntityextend
IPCustomEntityextend