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Detection rules › Kusto

Acronis - Multiple Endpoints Accessing Malicious URLs

Severity
medium
Time window
1d
Group by
DeviceName
Source
github.com/Azure/Azure-Sentinel

Multiple endpoints accessing malicious URLs could indicate an ongoing phishing attack, with several employees interacting with those URLs.

MITRE ATT&CK coverage

TacticTechniques
ExecutionT1204.001 User Execution: Malicious Link

Rule body kusto

id: 1385f0ce-69d9-4abf-8039-52080c8c7017
name: Acronis - Multiple Endpoints Accessing Malicious URLs
description: 'Multiple endpoints accessing malicious URLs could indicate an ongoing phishing attack, with several employees interacting with those URLs.'
severity: Medium
query: |
    CommonSecurityLog
    | where DeviceVendor == "Acronis"
    | where DeviceEventClassID == "MaliciousUrlDetected"
    | summarize MaliciousUrlDetected = count() by DeviceName
queryFrequency: 1h
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 2
tactics:
    - Execution
relevantTechniques:
    - T1204.001
incidentConfiguration:
    createIncident: true
    groupingConfiguration:
        enabled: true
        reopenClosedIncident: true
        lookbackDuration: P1D
        matchingMethod: AnyAlert
eventGroupingSettings:
    aggregationKind: SingleAlert
customDetails:
  DeviceName: DeviceName
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: HostName
        columnName: DeviceName
version: 1.0.0
kind: Scheduled
requiredDataConnectors: []

Stages and Predicates

Stage 1: source

CommonSecurityLog

Stage 2: where

| where DeviceVendor == "Acronis"

Stage 3: where

| where DeviceEventClassID == "MaliciousUrlDetected"

Stage 4: summarize

| summarize MaliciousUrlDetected = count() by DeviceName

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
DeviceEventClassIDeq
  • MaliciousUrlDetected transforms: cased
DeviceVendoreq
  • Acronis 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
DeviceNamesummarize
MaliciousUrlDetectedsummarize