detection.wiki

Detection rules › Kusto

Imperva - Forbidden HTTP request method in request

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

'Detects connections with unexpected HTTP request method.'

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1133 External Remote Services, T1190 Exploit Public-Facing Application

Rule body kusto

id: 7ebc9e24-319c-4786-9151-c898240463bc
name: Imperva - Forbidden HTTP request method in request
description: |
  'Detects connections with unexpected HTTP request method.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: ImpervaWAFCloudAPI
    dataTypes:
      - ImpervaWAFCloud
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1190
  - T1133
query: |
  let bl_http_methods = dynamic(['PUT', 'HEAD', 'OPTIONS', 'TRACE', 'POST']);
  ImpervaWAFCloud
  | where HttpRequestMethod in~ (bl_http_methods)
  | extend IPCustomEntity = SrcIpAddr, UrlCustomEntity = UrlOriginal
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: UrlCustomEntity
version: 1.0.0
kind: Scheduled

Stages and Predicates

Parameters

let bl_http_methods = dynamic(['PUT', 'HEAD', 'OPTIONS', 'TRACE', 'POST']);

Stage 1: source

ImpervaWAFCloud

Stage 2: where

| where HttpRequestMethod in~ (bl_http_methods)

Stage 3: extend

| extend IPCustomEntity = SrcIpAddr, UrlCustomEntity = UrlOriginal

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
HttpRequestMethodin
  • HEAD
  • OPTIONS
  • POST
  • PUT
  • TRACE

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
IPCustomEntityextend
UrlCustomEntityextend