Detection rules › Kusto
Bitglass - User Agent string has changed for user
'Detects when User Agent string has changed for user.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access |
Rule body
id: 4dd61530-859f-49e7-bd27-a173cb1a4589
name: Bitglass - User Agent string has changed for user
description: |
'Detects when User Agent string has changed for user.'
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 ua = makeset(HttpUserAgent) by User
| join (Bitglass
| where EventType =~ 'access'
| where EventMessage =~ 'Login') on User
| where ua !contains HttpUserAgent
| 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 ua = makeset(HttpUserAgent) by User
Stage 5: join
| join (Bitglass
| where EventType =~ 'access'
| where EventMessage =~ 'Login') on User
Stage 6: where
| where ua !contains HttpUserAgent
Stage 7: extend
| extend AccountCustomEntity = User
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
EventMessage | eq |
| field:"EventMessage" kind:eq value:"Login" |
EventType | eq |
| field:"EventType" kind:eq value:"access" |
ua | cross_field_compare |
| field:"ua" kind:cross_field_compare value:"HttpUserAgent" |
Output fields
These fields are emitted when the rule matches.
| Field | Source |
|---|---|
User | summarize |
ua | summarize |
AccountCustomEntity | extend |