Egress Defend - Dangerous Attachment Detected
Id | a0e55dd4-8454-4396-91e6-f28fec3d2cab |
Rulename | Egress Defend - Dangerous Attachment Detected |
Description | Defend has detected a user has a suspicious file type from a suspicious sender in their mailbox. |
Severity | Medium |
Tactics | Execution InitialAccess Persistence PrivilegeEscalation |
Techniques | T1204 T0853 T0863 T1566 T1546 T1546 |
Required data connectors | EgressDefend |
Kind | Scheduled |
Query frequency | 30m |
Query period | 30m |
Trigger threshold | 0 |
Trigger operator | gt |
Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Egress Defend/Analytic Rules/DangerousAttachmentReceived.yaml |
Version | 1.0.0 |
Arm template | a0e55dd4-8454-4396-91e6-f28fec3d2cab.json |
DefendAuditData
| where ThreatLevel == "suspicious" or ThreatLevel == "dangerous"
| mv-expand todynamic(Attachments)
| where Attachments.name matches regex @"(?i)^.*\.(doc|docx|docm|pdf|xls|xlsx|xlsm|html|zip)$(?-i)"
| summarize attachmentCount=count() by TimeGenerated, tostring(Attachments.name), Subject, From, Account_0_FullName = trim(@"[^@.\w]+",Recipients), timesClicked = LinksClicked, SenderIP
status: Available
queryFrequency: 30m
description: |
'Defend has detected a user has a suspicious file type from a suspicious sender in their mailbox.'
severity: Medium
version: 1.0.0
relevantTechniques:
- T1204
- T0853
- T0863
- T1566
- T1546
- T1546
name: Egress Defend - Dangerous Attachment Detected
triggerThreshold: 0
kind: Scheduled
query: |
DefendAuditData
| where ThreatLevel == "suspicious" or ThreatLevel == "dangerous"
| mv-expand todynamic(Attachments)
| where Attachments.name matches regex @"(?i)^.*\.(doc|docx|docm|pdf|xls|xlsx|xlsm|html|zip)$(?-i)"
| summarize attachmentCount=count() by TimeGenerated, tostring(Attachments.name), Subject, From, Account_0_FullName = trim(@"[^@.\w]+",Recipients), timesClicked = LinksClicked, SenderIP
alertDetailsOverride:
alertDisplayNameFormat: Alert - {{Account_0_FullName}} has suspicious attachment.
triggerOperator: gt
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Egress Defend/Analytic Rules/DangerousAttachmentReceived.yaml
requiredDataConnectors:
- connectorId: EgressDefend
dataTypes:
- EgressDefend_CL
tactics:
- Execution
- InitialAccess
- Persistence
- PrivilegeEscalation
tags:
- Defend
id: a0e55dd4-8454-4396-91e6-f28fec3d2cab
queryPeriod: 30m
entityMappings:
- fieldMappings:
- columnName: Account_0_FullName
identifier: FullName
entityType: Account
- fieldMappings:
- columnName: Attachments_name
identifier: Name
entityType: File
- fieldMappings:
- columnName: Account_0_FullName
identifier: MailboxPrimaryAddress
entityType: Mailbox
- fieldMappings:
- columnName: SenderIP
identifier: Address
entityType: IP
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"workspace": {
"type": "String"
}
},
"resources": [
{
"apiVersion": "2024-01-01-preview",
"id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/a0e55dd4-8454-4396-91e6-f28fec3d2cab')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/a0e55dd4-8454-4396-91e6-f28fec3d2cab')]",
"properties": {
"alertDetailsOverride": {
"alertDisplayNameFormat": "Alert - {{Account_0_FullName}} has suspicious attachment."
},
"alertRuleTemplateName": "a0e55dd4-8454-4396-91e6-f28fec3d2cab",
"customDetails": null,
"description": "'Defend has detected a user has a suspicious file type from a suspicious sender in their mailbox.'\n",
"displayName": "Egress Defend - Dangerous Attachment Detected",
"enabled": true,
"entityMappings": [
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "Account_0_FullName",
"identifier": "FullName"
}
]
},
{
"entityType": "File",
"fieldMappings": [
{
"columnName": "Attachments_name",
"identifier": "Name"
}
]
},
{
"entityType": "Mailbox",
"fieldMappings": [
{
"columnName": "Account_0_FullName",
"identifier": "MailboxPrimaryAddress"
}
]
},
{
"entityType": "IP",
"fieldMappings": [
{
"columnName": "SenderIP",
"identifier": "Address"
}
]
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Egress Defend/Analytic Rules/DangerousAttachmentReceived.yaml",
"query": "DefendAuditData\n| where ThreatLevel == \"suspicious\" or ThreatLevel == \"dangerous\"\n| mv-expand todynamic(Attachments)\n| where Attachments.name matches regex @\"(?i)^.*\\.(doc|docx|docm|pdf|xls|xlsx|xlsm|html|zip)$(?-i)\"\n| summarize attachmentCount=count() by TimeGenerated, tostring(Attachments.name), Subject, From, Account_0_FullName = trim(@\"[^@.\\w]+\",Recipients), timesClicked = LinksClicked, SenderIP\n",
"queryFrequency": "PT30M",
"queryPeriod": "PT30M",
"severity": "Medium",
"status": "Available",
"subTechniques": [],
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"Execution",
"InitialAccess",
"Persistence",
"PrivilegeEscalation"
],
"tags": [
"Defend"
],
"techniques": [
"T1204",
"T1546",
"T1566"
],
"templateVersion": "1.0.0",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}