ProofpointPOD - Suspicious attachment

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Id	f6a51e2c-2d6a-4f92-a090-cfb002ca611f
Rulename	ProofpointPOD - Suspicious attachment
Description	Detects when email contains suspicious attachment (file type).
Severity	Medium
Tactics	InitialAccess
Techniques	T1566
Required data connectors	ProofpointPOD
Kind	Scheduled
Query frequency	10m
Query period	10m
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Proofpoint On demand(POD) Email Security/Analytic Rules/ProofpointPODSuspiciousAttachment.yaml
Version	1.0.2
Arm template	f6a51e2c-2d6a-4f92-a090-cfb002ca611f.json

KQL

let lbtime = 10m;
let disallowed_ext = dynamic(['ps1', 'exe', 'vbs', 'js', 'scr']);
ProofpointPOD
| where TimeGenerated > ago(lbtime)
| where EventType == 'message'
| where NetworkDirection == 'inbound'
| where FilterDisposition !in ('reject', 'discard')
| extend attachedExt = todynamic(MsgParts)[0]['detectedExt']
| where tolower(attachedExt) in (disallowed_ext)
| project SrcUserUpn, AccountCustomEntity = parse_json(DstUserUpn)[0], attachedExt

YAML

name: ProofpointPOD - Suspicious attachment
id: f6a51e2c-2d6a-4f92-a090-cfb002ca611f
description: |
    'Detects when email contains suspicious attachment (file type).'
triggerThreshold: 0
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: FullName
  entityType: Account
version: 1.0.2
triggerOperator: gt
query: |
  let lbtime = 10m;
  let disallowed_ext = dynamic(['ps1', 'exe', 'vbs', 'js', 'scr']);
  ProofpointPOD
  | where TimeGenerated > ago(lbtime)
  | where EventType == 'message'
  | where NetworkDirection == 'inbound'
  | where FilterDisposition !in ('reject', 'discard')
  | extend attachedExt = todynamic(MsgParts)[0]['detectedExt']
  | where tolower(attachedExt) in (disallowed_ext)
  | project SrcUserUpn, AccountCustomEntity = parse_json(DstUserUpn)[0], attachedExt  
tactics:
- InitialAccess
kind: Scheduled
queryFrequency: 10m
severity: Medium
queryPeriod: 10m
requiredDataConnectors:
- dataTypes:
  - ProofpointPOD_message_CL
  connectorId: ProofpointPOD
status: Available
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Proofpoint On demand(POD) Email Security/Analytic Rules/ProofpointPODSuspiciousAttachment.yaml
relevantTechniques:
- T1566

ARM