Detection rules › Kusto

NGINX - Multiple client errors from single IP address

Status
available
Severity
medium
Time window
5m
Group by
SrcIpAddr
Source
github.com/Azure/Azure-Sentinel

'Detects multiple client errors from one source in short timeframe'

MITRE ATT&CK coverage

Rule body

id: 42771afe-edb3-4330-bc4a-abf6a5714454
name: NGINX - Multiple client errors from single IP address
description: |
  'Detects multiple client errors from one source in short timeframe'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: CustomLogsAma
    dataTypes:
      - NGINX_CL
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1190
  - T1133
query: |
  let threshold = 100;
  NGINXHTTPServer
  | where tolong(HttpStatusCode) >= 400 and tolong(HttpStatusCode) <= 499 
  | summarize MultipleClientErrors = count() by SrcIpAddr, bin(TimeGenerated, 5m)
  | where MultipleClientErrors > threshold
  | extend IPCustomEntity = SrcIpAddr
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
version: 1.0.2
kind: Scheduled

Stages and Predicates

Parameters

let threshold = 100;

Stage 1: source

NGINXHTTPServer

Stage 2: where

| where tolong(HttpStatusCode) >= 400 and tolong(HttpStatusCode) <= 499

Stage 3: summarize

| summarize MultipleClientErrors = count() by SrcIpAddr, bin(TimeGenerated, 5m)

Stage 4: where

| where MultipleClientErrors > threshold

Stage 5: extend

| extend IPCustomEntity = SrcIpAddr

Indicators

These rows show field, operator, and value matches.

Output fields

These fields are emitted when the rule matches.

FieldSource
MultipleClientErrorssummarize
SrcIpAddrsummarize
IPCustomEntityextend