Detection rules › Kusto
Trend Micro CAS - Multiple infected users
'Detects when same malware was detected for multiple user account.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | T1566 Phishing |
Rule body kusto
id: 65c2a6fe-ff7b-46b0-9278-61265f77f3bc
name: Trend Micro CAS - Multiple infected users
description: |
'Detects when same malware was detected for multiple user account.'
severity: High
status: Available
requiredDataConnectors:
- connectorId: TrendMicroCAS
dataTypes:
- TrendMicroCAS
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- InitialAccess
relevantTechniques:
- T1566
query: |
TrendMicroCAS
| where EventType has_all ('virtual', 'analyzer')
| where isnotempty(VirusName)
| summarize count() by DstUserName, VirusName, bin(TimeGenerated, 15m)
| where count_ >= 2
| extend AccountCustomEntity = DstUserName, MalwareCustomEntity = VirusName
entityMappings:
- entityType: Account
fieldMappings:
- identifier: Name
columnName: AccountCustomEntity
- entityType: Malware
fieldMappings:
- identifier: Name
columnName: MalwareCustomEntity
version: 1.0.1
kind: Scheduled
Stages and Predicates
Stage 1: source
TrendMicroCAS
Stage 2: where
| where EventType has_all ('virtual', 'analyzer')
Stage 3: where
| where isnotempty(VirusName)
Stage 4: summarize
| summarize count() by DstUserName, VirusName, bin(TimeGenerated, 15m)
Stage 5: where
| where count_ >= 2
Stage 6: extend
| extend AccountCustomEntity = DstUserName, MalwareCustomEntity = VirusName
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.
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.
| Field | Source |
|---|---|
DstUserName | summarize |
VirusName | summarize |
AccountCustomEntity | extend |
MalwareCustomEntity | extend |