Detection rules › Kusto

Oracle - Multiple user agents for single source

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

'Detects requests with different user agents from one source in short timeframe.'

MITRE ATT&CK coverage

Rule body kusto

id: 44c7d12a-573f-11ec-bf63-0242ac130002
name: Oracle - Multiple user agents for single source
description: |
  'Detects requests with different user agents from one source in short timeframe.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: CustomLogsAma
    dataTypes:
      - OracleWebLogicServer_CL
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1190
  - T1133
query: |
  let threshold = 5;
  OracleWebLogicServerEvent
  | where isnotempty(HttpUserAgentOriginal)
  | summarize ua_count=makeset(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 5m)
  | where array_length(ua_count) > threshold
  | extend IPCustomEntity = SrcIpAddr
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
version: 1.0.3
kind: Scheduled

Stages and Predicates

Parameters

let threshold = 5;

Stage 1: source

OracleWebLogicServerEvent

Stage 2: where

| where isnotempty(HttpUserAgentOriginal)

Stage 3: summarize

| summarize ua_count=makeset(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 5m)

Stage 4: where

| where array_length(ua_count) > threshold

Stage 5: extend

| extend IPCustomEntity = SrcIpAddr

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
HttpUserAgentOriginalis_not_null
  • (no value, null check)
ua_countgt
  • 5 transforms: array_length

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
SrcIpAddrsummarize
ua_countsummarize
IPCustomEntityextend