Detection rules › Kusto

TI map IP entity to Workday(ASimAuditEventLogs)

Severity
medium
Time window
14d
Group by
DvcIpAddr, IndicatorId, TI_ipEntity
Source
github.com/Azure/Azure-Sentinel

Detects a match in Workday activity from any IP Indicator of Compromise (IOC) provided by Threat Intelligence (TI).

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1071 Application Layer Protocol

Rule body kusto

id: a924d317-03d2-4420-a71f-4d347bda4bd8
name: TI map IP entity to Workday(ASimAuditEventLogs)
description: |
  Detects a match in Workday activity from any IP Indicator of Compromise (IOC) provided by Threat Intelligence (TI).
severity: Medium
requiredDataConnectors:
  - connectorId: ThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: ThreatIntelligenceTaxii
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: Workday
    dataTypes:
      - Workday
  - connectorId: MicrosoftDefenderThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1071
query: |
  let dtLookBack = 1h; // Define the lookback period for audit events
  let ioc_lookBack = 14d; // Define the lookback period for threat intelligence indicators
  ThreatIntelligenceIndicator 
  | where TimeGenerated >= ago(ioc_lookBack) // Filter threat intelligence indicators within the lookback period
  | where isnotempty(NetworkIP)
        or isnotempty(EmailSourceIpAddress)
        or isnotempty(NetworkDestinationIP)
        or isnotempty(NetworkSourceIP) // Filter for indicators with relevant IP fields
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId // Get the latest indicator time for each IndicatorId
    | extend TI_ipEntity = coalesce(NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress) // Combine IP fields into a single entity
    | where Active == true and ExpirationDateTime > now() // Filter for active indicators that have not expired
    | join kind=inner (
        ASimAuditEventLogs
        | where EventVendor == "Workday" // Filter for Workday events
        | where TimeGenerated >= ago(dtLookBack) // Filter events within the lookback period
        | where isnotempty(DvcIpAddr) // Filter for events with a device IP address
        | extend WD_TimeGenerated = EventStartTime // Rename the event start time column
        | project WD_TimeGenerated, ActorUsername, DvcIpAddr, Operation, Object // Select relevant columns
        )
        on $left.TI_ipEntity == $right.DvcIpAddr // Join on the IP entity
    | project
        LatestIndicatorTime,
        Description,
        ActivityGroupNames,
        IndicatorId,
        ThreatType,
        Url,
        ExpirationDateTime,
        ConfidenceScore,
        WD_TimeGenerated,
        ActorUsername,
        DvcIpAddr,
        Operation,
        Object // Select relevant columns after the join
    | extend
        timestamp = WD_TimeGenerated,
        Name = tostring(split(ActorUsername, '@', 0)),
        UPNSuffix = tostring(split(ActorUsername, '@', 1)) // Add additional fields for timestamp, name, and UPN suffix    
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: ActorUsername
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: DvcIpAddr
version: 1.0.0
kind: Scheduled

Stages and Predicates

Parameters

let dtLookBack = 1h;
let ioc_lookBack = 14d;

Stage 1: source

ThreatIntelligenceIndicator

Stage 2: where

| where TimeGenerated >= ago(ioc_lookBack)

Stage 3: where

| where isnotempty(NetworkIP)
      or isnotempty(EmailSourceIpAddress)
      or isnotempty(NetworkDestinationIP)
      or isnotempty(NetworkSourceIP)

Stage 4: summarize

| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId

Stage 5: extend

| extend TI_ipEntity = coalesce(NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress)

Stage 6: where

| where Active == true and ExpirationDateTime > now()

Stage 7: join

| join kind=inner (
      ASimAuditEventLogs
      | where EventVendor == "Workday"
      | where TimeGenerated >= ago(dtLookBack)
      | where isnotempty(DvcIpAddr)
      | extend WD_TimeGenerated = EventStartTime
      | project WD_TimeGenerated, ActorUsername, DvcIpAddr, Operation, Object
      )
      on $left.TI_ipEntity == $right.DvcIpAddr

Stage 8: project

| project
      LatestIndicatorTime,
      Description,
      ActivityGroupNames,
      IndicatorId,
      ThreatType,
      Url,
      ExpirationDateTime,
      ConfidenceScore,
      WD_TimeGenerated,
      ActorUsername,
      DvcIpAddr,
      Operation,
      Object

Stage 9: extend

| extend
      timestamp = WD_TimeGenerated,
      Name = tostring(split(ActorUsername, '@', 0)),
      UPNSuffix = tostring(split(ActorUsername, '@', 1))

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
Activeeq
  • true transforms: cased
DvcIpAddris_not_null
  • (no value, null check)
EmailSourceIpAddressis_not_null
  • (no value, null check)
EventVendoreq
  • Workday transforms: cased
NetworkDestinationIPis_not_null
  • (no value, null check)
NetworkIPis_not_null
  • (no value, null check)
NetworkSourceIPis_not_null
  • (no value, null check)

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
ActivityGroupNamesproject
ActorUsernameproject
ConfidenceScoreproject
Descriptionproject
DvcIpAddrproject
ExpirationDateTimeproject
IndicatorIdproject
LatestIndicatorTimeproject
Objectproject
Operationproject
ThreatTypeproject
Urlproject
WD_TimeGeneratedproject
Nameextend
UPNSuffixextend
timestampextend