Tailscale: New API access token or OAuth client created

Status: available
Severity: medium
Time window: 15m
Source: github.com/Azure/Azure-Sentinel

Identifies when a new API access token or OAuth client is created in the tailnet. These grant programmatic access - verify the actor and intent.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1098` Account Manipulation `T1136` Create Account

Rule body

id: 668b43fd-cf28-961a-85af-957850df5027
name: "Tailscale: New API access token or OAuth client created"
description: |
  Identifies when a new API access token or OAuth client is created in the tailnet. These grant programmatic access - verify the actor and intent.
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: TailscaleCCF
    dataTypes:
      - Tailscale_Audit_CL
queryFrequency: 15m
queryPeriod: 15m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Persistence
  - CredentialAccess
relevantTechniques:
  - T1098
  - T1136
query: |
  Tailscale_Audit_CL
        | where Action == "CREATE"
        | where tostring(Target.type) in ("API_KEY", "OAUTH_CLIENT")
        | extend ActorLogin = tostring(Actor.loginName)
        | extend TargetName = tostring(Target.name)
        | extend TargetId = tostring(Target.id)
        | project TimeGenerated, ActorLogin, Action, TargetName, TargetId, Origin, New
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: ActorLogin
incidentConfiguration:
  createIncident: true
  groupingConfiguration:
    enabled: true
    reopenClosedIncident: false
    lookbackDuration: PT5H
    matchingMethod: AllEntities
kind: Scheduled
version: 1.0.0

Stages and Predicates

Stage 1: `source`

Tailscale_Audit_CL

Stage 2: `where`

| where Action == "CREATE"

Stage 3: `where`

| where tostring(Target.type) in ("API_KEY", "OAUTH_CLIENT")

Stage 4: `extend` (3 consecutive steps)

| extend ActorLogin = tostring(Actor.loginName)
| extend TargetName = tostring(Target.name)
| extend TargetId = tostring(Target.id)

Stage 5: `project`

| project TimeGenerated, ActorLogin, Action, TargetName, TargetId, Origin, New

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Action`	eq	`CREATE`	`field:"Action" kind:eq value:"CREATE"`
`type`	in	`API_KEY` transforms: `tostring` `OAUTH_CLIENT` transforms: `tostring`	`field:"type" kind:in`

Output fields

These fields are emitted when the rule matches.

Field	Source
`Action`	`project`
`ActorLogin`	`project`
`New`	`project`
`Origin`	`project`
`TargetId`	`project`
`TargetName`	`project`
`TimeGenerated`	`project`

Tailscale: New API access token or OAuth client created

MITRE ATT&CK coverage

Rule body

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: extend (3 consecutive steps)