Detection rules › Kusto

Palo Alto Prisma Cloud - High risk score alert

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

'Detects alerts with high risk score value.'

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1133 External Remote Services

Rule body kusto

id: 617b02d8-0f47-4f3c-afed-1926a45e7b28
name: Palo Alto Prisma Cloud - High risk score alert
description: |
  'Detects alerts with high risk score value.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: PaloAltoPrismaCloud
    dataTypes:
      - PaloAltoPrismaCloud
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1133
query: |
  PaloAltoPrismaCloud
  | where Reason =~ 'NEW_ALERT'
  | where Status =~ 'open'
  | extend r_score = 0.85 * toint(RiskDetailRiskScoreMaxScore)
  | extend i_RiskDetailRiskScoreScore = toint(RiskDetailRiskScoreScore)
  | where i_RiskDetailRiskScoreScore > r_score
  | extend AccountCustomEntity = UserName
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountCustomEntity
version: 1.0.1
kind: Scheduled

Stages and Predicates

Stage 1: source

PaloAltoPrismaCloud

Stage 2: where

| where Reason =~ 'NEW_ALERT'

Stage 3: where

| where Status =~ 'open'

Stage 4: extend

| extend r_score = 0.85 * toint(RiskDetailRiskScoreMaxScore)

Stage 5: extend

| extend i_RiskDetailRiskScoreScore = toint(RiskDetailRiskScoreScore)

Stage 6: where

| where i_RiskDetailRiskScoreScore > r_score

Stage 7: extend

| extend AccountCustomEntity = UserName

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
Reasoneq
  • NEW_ALERT
Statuseq
  • open
i_RiskDetailRiskScoreScoregt
  • r_score 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
r_scoreextend
i_RiskDetailRiskScoreScoreextend
AccountCustomEntityextend