Cisco SEG - Multiple suspiciuos attachments received

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Id	dfdb9a73-4335-4bb4-b29b-eb713bce61a6
Rulename	Cisco SEG - Multiple suspiciuos attachments received
Description	Detects possibly phishing emails.
Severity	High
Tactics	InitialAccess
Techniques	T1566
Required data connectors	CefAma
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CiscoSEG/Analytic Rules/CiscoSEGMultipleSuspiciousEmails.yaml
Version	1.0.3
Arm template	dfdb9a73-4335-4bb4-b29b-eb713bce61a6.json

KQL

let r_threshold = 5;
CiscoSEGEvent
| where NetworkDirection =~ 'Incoming'
| where isnotempty(EventMessage)
| where strlen(EventMessage) < 20
| summarize rec=makeset(DstUserName) by EventMessage, bin(TimeGenerated, 10m)
| where array_length(rec) > r_threshold
| extend AccountCustomEntity = rec

YAML

version: 1.0.3
id: dfdb9a73-4335-4bb4-b29b-eb713bce61a6
name: Cisco SEG - Multiple suspiciuos attachments received
queryPeriod: 1h
requiredDataConnectors:
- connectorId: CefAma
  dataTypes:
  - CommonSecurityLog
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CiscoSEG/Analytic Rules/CiscoSEGMultipleSuspiciousEmails.yaml
query: |
  let r_threshold = 5;
  CiscoSEGEvent
  | where NetworkDirection =~ 'Incoming'
  | where isnotempty(EventMessage)
  | where strlen(EventMessage) < 20
  | summarize rec=makeset(DstUserName) by EventMessage, bin(TimeGenerated, 10m)
  | where array_length(rec) > r_threshold
  | extend AccountCustomEntity = rec  
relevantTechniques:
- T1566
entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: AccountCustomEntity
severity: High
kind: Scheduled
triggerThreshold: 0
triggerOperator: gt
tactics:
- InitialAccess
status: Available
queryFrequency: 1h
description: |
    'Detects possibly phishing emails.'

ARM