ThreatConnect TI map Email entity to OfficeActivity
Id | 4f7ade3e-7121-5274-83ea-d7ed22a01fea |
Rulename | ThreatConnect TI map Email entity to OfficeActivity |
Description | Identifies a match in OfficeActivity table from any Email IOC from ThreatConnect TI |
Severity | Medium |
Tactics | CommandAndControl |
Techniques | T1071 |
Required data connectors | MicrosoftDefenderThreatIntelligence Office365 ThreatIntelligence ThreatIntelligenceTaxii |
Kind | Scheduled |
Query frequency | 1h |
Query period | 14d |
Trigger threshold | 0 |
Trigger operator | gt |
Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/ThreatConnect/Analytic Rules/ThreatConnect_EmailEntity_OfficeActivity.yaml |
Version | 1.2.5 |
Arm template | 4f7ade3e-7121-5274-83ea-d7ed22a01fea.json |
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let emailregex = @'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$';
ThreatIntelligenceIndicator
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where ExpirationDateTime > now() and Active == true
// Filter out non ThreatConnect TI Sources
| where SourceSystem startswith "ThreatConnect-"
//Filtering the table for Email related IOCs
| where isnotempty(EmailSenderAddress)
// using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated
| join kind=innerunique (
OfficeActivity | where TimeGenerated >= ago(dt_lookBack) and isnotempty(UserId)
| where UserId matches regex emailregex
| extend OfficeActivity_TimeGenerated = TimeGenerated
)
on $left.EmailSenderAddress == $right.UserId
| where OfficeActivity_TimeGenerated < ExpirationDateTime
| summarize OfficeActivity_TimeGenerated = arg_max(OfficeActivity_TimeGenerated, *) by IndicatorId, UserId
| project OfficeActivity_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
EmailSenderName, EmailRecipient, EmailSourceDomain, EmailSourceIpAddress, EmailSubject, FileHashValue, FileHashType, UserId, ClientIP, Operation, UserType, RecordType, OfficeWorkload, Parameters
| extend Name = tostring(split(UserId, '@', 0)[0]), UPNSuffix = tostring(split(UserId, '@', 1)[0])
| extend timestamp = OfficeActivity_TimeGenerated
id: 4f7ade3e-7121-5274-83ea-d7ed22a01fea
triggerOperator: gt
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/ThreatConnect/Analytic Rules/ThreatConnect_EmailEntity_OfficeActivity.yaml
requiredDataConnectors:
- dataTypes:
- OfficeActivity
connectorId: Office365
- dataTypes:
- ThreatIntelligenceIndicator
connectorId: ThreatIntelligence
- dataTypes:
- ThreatIntelligenceIndicator
connectorId: ThreatIntelligenceTaxii
- dataTypes:
- ThreatIntelligenceIndicator
connectorId: MicrosoftDefenderThreatIntelligence
description: |
'Identifies a match in OfficeActivity table from any Email IOC from ThreatConnect TI'
severity: Medium
queryPeriod: 14d
kind: Scheduled
tactics:
- CommandAndControl
queryFrequency: 1h
query: |
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let emailregex = @'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$';
ThreatIntelligenceIndicator
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where ExpirationDateTime > now() and Active == true
// Filter out non ThreatConnect TI Sources
| where SourceSystem startswith "ThreatConnect-"
//Filtering the table for Email related IOCs
| where isnotempty(EmailSenderAddress)
// using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated
| join kind=innerunique (
OfficeActivity | where TimeGenerated >= ago(dt_lookBack) and isnotempty(UserId)
| where UserId matches regex emailregex
| extend OfficeActivity_TimeGenerated = TimeGenerated
)
on $left.EmailSenderAddress == $right.UserId
| where OfficeActivity_TimeGenerated < ExpirationDateTime
| summarize OfficeActivity_TimeGenerated = arg_max(OfficeActivity_TimeGenerated, *) by IndicatorId, UserId
| project OfficeActivity_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
EmailSenderName, EmailRecipient, EmailSourceDomain, EmailSourceIpAddress, EmailSubject, FileHashValue, FileHashType, UserId, ClientIP, Operation, UserType, RecordType, OfficeWorkload, Parameters
| extend Name = tostring(split(UserId, '@', 0)[0]), UPNSuffix = tostring(split(UserId, '@', 1)[0])
| extend timestamp = OfficeActivity_TimeGenerated
version: 1.2.5
triggerThreshold: 0
entityMappings:
- entityType: Account
fieldMappings:
- columnName: Name
identifier: Name
- columnName: UPNSuffix
identifier: UPNSuffix
- entityType: IP
fieldMappings:
- columnName: ClientIP
identifier: Address
- entityType: URL
fieldMappings:
- columnName: Url
identifier: Url
name: ThreatConnect TI map Email entity to OfficeActivity
relevantTechniques:
- T1071
{
"$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/4f7ade3e-7121-5274-83ea-d7ed22a01fea')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/4f7ade3e-7121-5274-83ea-d7ed22a01fea')]",
"properties": {
"alertRuleTemplateName": "4f7ade3e-7121-5274-83ea-d7ed22a01fea",
"customDetails": null,
"description": "'Identifies a match in OfficeActivity table from any Email IOC from ThreatConnect TI'\n",
"displayName": "ThreatConnect TI map Email entity to OfficeActivity",
"enabled": true,
"entityMappings": [
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "Name",
"identifier": "Name"
},
{
"columnName": "UPNSuffix",
"identifier": "UPNSuffix"
}
]
},
{
"entityType": "IP",
"fieldMappings": [
{
"columnName": "ClientIP",
"identifier": "Address"
}
]
},
{
"entityType": "URL",
"fieldMappings": [
{
"columnName": "Url",
"identifier": "Url"
}
]
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/ThreatConnect/Analytic Rules/ThreatConnect_EmailEntity_OfficeActivity.yaml",
"query": "let dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nlet emailregex = @'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\\.[a-zA-Z0-9-.]+$';\nThreatIntelligenceIndicator\n | where TimeGenerated >= ago(ioc_lookBack)\n | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId\n | where ExpirationDateTime > now() and Active == true\n// Filter out non ThreatConnect TI Sources\n| where SourceSystem startswith \"ThreatConnect-\"\n//Filtering the table for Email related IOCs\n| where isnotempty(EmailSenderAddress)\n// using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated\n| join kind=innerunique (\n OfficeActivity | where TimeGenerated >= ago(dt_lookBack) and isnotempty(UserId)\n | where UserId matches regex emailregex\n | extend OfficeActivity_TimeGenerated = TimeGenerated\n)\non $left.EmailSenderAddress == $right.UserId\n| where OfficeActivity_TimeGenerated < ExpirationDateTime\n| summarize OfficeActivity_TimeGenerated = arg_max(OfficeActivity_TimeGenerated, *) by IndicatorId, UserId\n| project OfficeActivity_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,\nEmailSenderName, EmailRecipient, EmailSourceDomain, EmailSourceIpAddress, EmailSubject, FileHashValue, FileHashType, UserId, ClientIP, Operation, UserType, RecordType, OfficeWorkload, Parameters\n| extend Name = tostring(split(UserId, '@', 0)[0]), UPNSuffix = tostring(split(UserId, '@', 1)[0])\n| extend timestamp = OfficeActivity_TimeGenerated\n",
"queryFrequency": "PT1H",
"queryPeriod": "P14D",
"severity": "Medium",
"subTechniques": [],
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"CommandAndControl"
],
"techniques": [
"T1071"
],
"templateVersion": "1.2.5",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}