MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access |
Rule body
id: 9e7b3811-d743-479c-a296-635410562429
name: Trend Micro CAS - Possible phishing mail
description: |
'Detects possible phishing mail.'
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: TrendMicroCAS
dataTypes:
- TrendMicroCAS
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- InitialAccess
relevantTechniques:
- T1566
query: |
let threshold = 5;
TrendMicroCAS
| where EventCategoryType in~ ('exchange', 'gmail', 'exchangeserver')
| where isnotempty(SrcFileName)
| where isnotempty(SecurityRiskName)
| summarize r_users = makeset(DstUserName) by SrcFileName, bin(TimeGenerated, 30m)
| where array_length(r_users) > threshold
| extend AccountCustomEntity = r_users
entityMappings:
- entityType: Account
fieldMappings:
- identifier: Name
columnName: AccountCustomEntity
version: 1.0.0
kind: Scheduled
Stages and Predicates
Parameters
let threshold = 5;
Stage 1: source
TrendMicroCAS
Stage 2: where
| where EventCategoryType in~ ('exchange', 'gmail', 'exchangeserver')
Stage 3: where
| where isnotempty(SrcFileName)
Stage 4: where
| where isnotempty(SecurityRiskName)
Stage 5: summarize
| summarize r_users = makeset(DstUserName) by SrcFileName, bin(TimeGenerated, 30m)
Stage 6: where
| where array_length(r_users) > threshold
Stage 7: extend
| extend AccountCustomEntity = r_users
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
EventCategoryType | in |
| field:"EventCategoryType" kind:in |
SecurityRiskName | is_not_null | field:"SecurityRiskName" kind:is_not_null | |
SrcFileName | is_not_null | field:"SrcFileName" kind:is_not_null |
Output fields
These fields are emitted when the rule matches.
| Field | Source |
|---|---|
SrcFileName | summarize |
r_users | summarize |
AccountCustomEntity | extend |