Detection rules › Kusto

Trend Micro CAS - Multiple infected users

Status
available
Severity
high
Time window
15m
Group by
DstUserName, VirusName
Source
github.com/Azure/Azure-Sentinel

'Detects when same malware was detected for multiple user account.'

MITRE ATT&CK coverage

TacticTechniques
Initial Access

Rule body

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

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventTypematch
  • analyzer transforms: term
  • virtual transforms: term
field:"EventType" kind:match
VirusNameis_not_null
  • (no value, null check)
field:"VirusName" kind:is_not_null
count_ge
  • 2
field:"count_" kind:ge value:"2"

Output fields

These fields are emitted when the rule matches.

FieldSource
DstUserNamesummarize
VirusNamesummarize
AccountCustomEntityextend
MalwareCustomEntityextend