detection.wiki

Detection rules › Kusto

API - Password Cracking

Status
available
Severity
high
Time window
5m
Source
github.com/Azure/Azure-Sentinel

'42Crunch API protection against password cracking'

MITRE ATT&CK coverage

TacticTechniques
Credential Access

Rule body

id: d951d64d-0ecd-4675-8c79-6c870d5f72ac
name: API - Password Cracking
description: |
  '42Crunch API protection against password cracking'
severity: High
requiredDataConnectors:
  - connectorId: 42CrunchAPIProtection
    dataTypes:
      - FortyTwoCrunchAPIProtection
  - connectorId: FortyTwoCrunchAPIProtection
    dataTypes:
      - FortyTwoCrunchAPIProtection
queryFrequency: 5m
queryPeriod: 5m
triggerOperator: gt
triggerThreshold: 0
eventGroupingSettings:
  aggregationKind: SingleAlert
status: Available
tactics:
  - CredentialAccess
relevantTechniques:
  - T1110
  - T1555
  - T1187
query: |
  let loginRec = FortyTwoCrunchAPIProtection
  | where TimeGenerated >= ago(5m) 
  | project-away NonBlockingMode, SourcePort, DestinationPort, Query, ApiId, RequestHeader, ResponseHeader, Errors, EventType, Uuid
  | where UriPath has "/api/login?user=" and Status == 403;
  let recCount = iff((toscalar(loginRec | count) > 10), 1, 0);
  loginRec | take recCount
customDetails:
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SourceIp
  - entityType: Host
    fieldMappings:
      - identifier: HostName
        columnName: Hostname
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: InstanceName
version: 3.0.1
kind: Scheduled

Stages and Predicates

let loginRec is inlined into the numbered stages below.

Let binding: recCount used in Stage 5

let recCount = iff((toscalar(loginRec | count) > 10), 1, 0);

Stages 1 to 4 define let loginRec (the rule's main pipeline source); stage 5 runs on it.

Stage 1: source

FortyTwoCrunchAPIProtection

Stage 2: where

| where TimeGenerated >= ago(5m)

Stage 3: project-away

| project-away NonBlockingMode, SourcePort, DestinationPort, Query, ApiId, RequestHeader, ResponseHeader, Errors, EventType, Uuid

Stage 4: where

| where UriPath has "/api/login?user=" and Status == 403

Stage 5: take

loginRec
| take recCount

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Statuseq
  • 403
field:"Status" kind:eq value:"403"
UriPathmatch
  • /api/login?user= transforms: term
field:"UriPath" kind:match value:"/api/login?user="