Detection rules › Kusto

ProofpointPOD - High risk message not discarded

Status
available
Severity
low
Time window
10m
Source
github.com/Azure/Azure-Sentinel

'Detects when email with high risk score was not rejected or discarded by filters.'

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1566 Phishing

Rule body kusto

id: c7cd6073-6d2c-4284-a5c8-da27605bdfde
name: ProofpointPOD - High risk message not discarded
description: |
  'Detects when email with high risk score was not rejected or discarded by filters.'
severity: Low
status: Available 
requiredDataConnectors:
  - connectorId: ProofpointPOD
    dataTypes:
      - ProofpointPOD_message_CL
queryFrequency: 10m
queryPeriod: 10m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1566
query: |
  let lbtime = 10m;
  ProofpointPOD
  | where TimeGenerated > ago(lbtime)
  | where EventType == 'message'
  | where NetworkDirection == 'inbound'
  | where FilterDisposition !in ('reject', 'discard')
  | where FilterModulesSpamScoresOverall == '100'
  | project SrcUserUpn, DstUserUpn
  | extend AccountCustomEntity = SrcUserUpn
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: AccountCustomEntity
version: 1.0.1
kind: Scheduled

Stages and Predicates

Parameters

let lbtime = 10m;

Stage 1: source

ProofpointPOD

Stage 2: where

| where TimeGenerated > ago(lbtime)

Stage 3: where

| where EventType == 'message'

Stage 4: where

| where NetworkDirection == 'inbound'

Stage 5: where

| where FilterDisposition !in ('reject', 'discard')

Stage 6: where

| where FilterModulesSpamScoresOverall == '100'

Stage 7: project

| project SrcUserUpn, DstUserUpn

Stage 8: extend

| extend AccountCustomEntity = SrcUserUpn

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
FilterDispositionindiscard, reject

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
EventTypeeq
  • message transforms: cased
FilterModulesSpamScoresOveralleq
  • 100 transforms: cased
NetworkDirectioneq
  • inbound 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
DstUserUpnproject
SrcUserUpnproject
AccountCustomEntityextend