Detection rules › Kusto

Bitglass - Login from new device

Status
available
Severity
medium
Time window
14d
Group by
User
Source
github.com/Azure/Azure-Sentinel

'Detects when a user logins from new device.'

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1078 Valid Accounts

Rule body kusto

id: bfca0251-1581-4185-906b-4805099e3216
name: Bitglass - Login from new device
description: |
  'Detects when a user logins from new device.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: Bitglass
    dataTypes:
      - Bitglass
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1078
query: |
  Bitglass
  | where EventType =~ 'access'
  | where EventMessage =~ 'Login'
  | summarize dev = makeset(Dvc) by User
  | join (Bitglass
          | where EventType =~ 'access'
          | where EventMessage =~ 'Login') on User
  | where dev !contains Dvc
  | extend AccountCustomEntity = User
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountCustomEntity
version: 1.0.0
kind: Scheduled

Stages and Predicates

Stage 1: source

Bitglass

Stage 2: where

| where EventType =~ 'access'

Stage 3: where

| where EventMessage =~ 'Login'

Stage 4: summarize

| summarize dev = makeset(Dvc) by User

Stage 5: join

| join (Bitglass
        | where EventType =~ 'access'
        | where EventMessage =~ 'Login') on User

Stage 6: where

| where dev !contains Dvc

Stage 7: extend

| extend AccountCustomEntity = User

Exclusions

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

FieldKindExcluded values
devcontainsDvc

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.

FieldKindValues
EventMessageeq
  • Login
EventTypeeq
  • access

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.

FieldSource
Usersummarize
devsummarize
AccountCustomEntityextend