Digital Guardian - Exfiltration to private email

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Id	edead9b5-243a-466b-ae78-2dae32ab1117
Rulename	Digital Guardian - Exfiltration to private email
Description	Detects exfiltration to private email.
Severity	High
Tactics	Exfiltration
Techniques	T1048
Required data connectors	SyslogAma
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/Digital Guardian Data Loss Prevention/Analytic Rules/DigitalGuardianFileSentToExternal.yaml
Version	1.0.2
Arm template	edead9b5-243a-466b-ae78-2dae32ab1117.json

KQL

DigitalGuardianDLPEvent
| where NetworkApplicationProtocol =~ 'SMTP'
| where isnotempty(inspected_document)
| extend s_user = substring(SrcUserName, 0, indexof(SrcUserName, '@'))
| extend d_user = substring(DstUserName, 0, indexof(DstUserName, '@'))
| extend s_domain = extract(@'@(.*)', 1, SrcUserName)
| extend d_domain = extract(@'@(.*)', 1, DstUserName)
| where s_domain != d_domain
| where s_user == d_user
| extend AccountCustomEntity = SrcUserName

YAML

name: Digital Guardian - Exfiltration to private email
query: |
  DigitalGuardianDLPEvent
  | where NetworkApplicationProtocol =~ 'SMTP'
  | where isnotempty(inspected_document)
  | extend s_user = substring(SrcUserName, 0, indexof(SrcUserName, '@'))
  | extend d_user = substring(DstUserName, 0, indexof(DstUserName, '@'))
  | extend s_domain = extract(@'@(.*)', 1, SrcUserName)
  | extend d_domain = extract(@'@(.*)', 1, DstUserName)
  | where s_domain != d_domain
  | where s_user == d_user
  | extend AccountCustomEntity = SrcUserName  
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: AccountCustomEntity
    identifier: Name
queryPeriod: 1h
version: 1.0.2
tactics:
- Exfiltration
triggerOperator: gt
kind: Scheduled
triggerThreshold: 0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Digital Guardian Data Loss Prevention/Analytic Rules/DigitalGuardianFileSentToExternal.yaml
relevantTechniques:
- T1048
id: edead9b5-243a-466b-ae78-2dae32ab1117
severity: High
requiredDataConnectors:
- connectorId: SyslogAma
  datatypes:
  - Syslog
status: Available
description: |
    'Detects exfiltration to private email.'
queryFrequency: 1h

ARM