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Detection rules › Kusto

ApexOne - Inbound remote access connection

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

'Detects inbound remote access connection.'

MITRE ATT&CK coverage

TacticTechniques
Lateral MovementT1021 Remote Services

Rule body kusto

id: 6303235a-ee70-42a4-b969-43e7b969b916
name: ApexOne - Inbound remote access connection
description: |
  'Detects inbound remote access connection.'
severity: High
status: Available
requiredDataConnectors:
  - connectorId: CefAma
    dataTypes:
      - CommonSecurityLog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - LateralMovement
relevantTechniques:
  - T1021
query: |
  TMApexOneEvent
  | where EventSubType has "WB"
  | where NetworkDirection == 1
  | where ApplicationProtocol in ('15', '17', '20', '22', '23', '27', '36', '37')
  | extend IPCustomEntity = SrcIpAddr, AccountCustomEntity = DstUserName
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountCustomEntity
version: 1.0.3
kind: Scheduled

Stages and Predicates

Stage 1: source

TMApexOneEvent

Stage 2: where

| where EventSubType has "WB"

Stage 3: where

| where NetworkDirection == 1

Stage 4: where

| where ApplicationProtocol in ('15', '17', '20', '22', '23', '27', '36', '37')

Stage 5: extend

| extend IPCustomEntity = SrcIpAddr, AccountCustomEntity = DstUserName

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
ApplicationProtocolin
  • 15 transforms: cased
  • 17 transforms: cased
  • 20 transforms: cased
  • 22 transforms: cased
  • 23 transforms: cased
  • 27 transforms: cased
  • 36 transforms: cased
  • 37 transforms: cased
EventSubTypematch
  • WB transforms: term
NetworkDirectioneq
  • 1 transforms: cased

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
AccountCustomEntityextend
IPCustomEntityextend