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Detection rules › Kusto

Cloudflare - Bad client IP

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

'Detects requests from IP with bad reputation index.'

MITRE ATT&CK coverage

TacticTechniques
Initial Access

Rule body

id: a7ce6135-9d55-4f14-b058-adc2e920a4fb
name: Cloudflare - Bad client IP
description: |
  'Detects requests from IP with bad reputation index.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: CloudflareDataConnector
    dataTypes:
      - Cloudflare
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1190
  - T1133
query: |
  let ip_reputation = dynamic(['unknown', 'badHost', 'greylist', 'securityScanner', 'scan', 'tor']);
  Cloudflare
  | where ClientIPClass in~ (ip_reputation)
  | extend CompleteUrl = strcat(HttpRequestHeaderHost,ClientRequestPath)
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SrcIpAddr
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: CompleteUrl
version: 1.0.1
kind: Scheduled

Stages and Predicates

Parameters

let ip_reputation = dynamic(['unknown', 'badHost', 'greylist', 'securityScanner', 'scan', 'tor']);

Stage 1: source

Cloudflare

Stage 2: where

| where ClientIPClass in~ (ip_reputation)

Stage 3: extend

| extend CompleteUrl = strcat(HttpRequestHeaderHost,ClientRequestPath)

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
ClientIPClassin
  • badHost
  • greylist
  • scan
  • securityScanner
  • tor
  • unknown
field:"ClientIPClass" kind:in

Output fields

These fields are emitted when the rule matches.

FieldSource
CompleteUrlextend