TI map Email entity to SecurityEvent
Id | 2fc5d810-c9cc-491a-b564-841427ae0e50 |
Rulename | TI map Email entity to SecurityEvent |
Description | Identifies a match in SecurityEvent table from any Email IOC from TI |
Severity | Medium |
Tactics | Impact |
Required data connectors | SecurityEvents ThreatIntelligence ThreatIntelligenceTaxii WindowsForwardedEvents WindowsSecurityEvents |
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/Threat Intelligence/Analytic Rules/EmailEntity_SecurityEvent.yaml |
Version | 1.3.2 |
Arm template | 2fc5d810-c9cc-491a-b564-841427ae0e50.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) and ExpirationDateTime > now()
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true
//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 (
(union isfuzzy=true
(SecurityEvent
| where TimeGenerated >= ago(dt_lookBack) and isnotempty(TargetUserName)
//Normalizing the column to lower case for exact match with EmailSenderAddress column
| extend TargetUserName = tolower(TargetUserName)
// renaming timestamp column so it is clear the log this came from SecurityEvent table
| extend SecurityEvent_TimeGenerated = TimeGenerated
),
(WindowsEvent
| where TimeGenerated >= ago(dt_lookBack)
| extend TargetUserName = tostring(EventData.TargetUserName)
| where isnotempty(TargetUserName)
//Normalizing the column to lower case for exact match with EmailSenderAddress column
| extend TargetUserName = tolower(TargetUserName)
// renaming timestamp column so it is clear the log this came from SecurityEvent table
| extend SecurityEvent_TimeGenerated = TimeGenerated
))
)
on $left.EmailSenderAddress == $right.TargetUserName
| where SecurityEvent_TimeGenerated < ExpirationDateTime
| summarize SecurityEvent_TimeGenerated = arg_max(SecurityEvent_TimeGenerated, *) by IndicatorId, TargetUserName
| project SecurityEvent_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
EmailSenderName, EmailRecipient, EmailSourceDomain, EmailSourceIpAddress, EmailSubject, FileHashValue, FileHashType, Computer, EventID, TargetUserName, Activity, IpAddress, AccountType,
LogonTypeName, LogonProcessName, Status, SubStatus
| extend
timestamp = SecurityEvent_TimeGenerated,
AccountCustomEntity = TargetUserName,
IPCustomEntity = IpAddress,
HostCustomEntity = Computer,
URLCustomEntity = Url
triggerOperator: gt
id: 2fc5d810-c9cc-491a-b564-841427ae0e50
queryFrequency: 1h
entityMappings:
- entityType: Account
fieldMappings:
- columnName: AccountCustomEntity
identifier: FullName
- entityType: Host
fieldMappings:
- columnName: HostCustomEntity
identifier: FullName
- entityType: IP
fieldMappings:
- columnName: IPCustomEntity
identifier: Address
- entityType: URL
fieldMappings:
- columnName: URLCustomEntity
identifier: Url
requiredDataConnectors:
- dataTypes:
- ThreatIntelligenceIndicator
connectorId: ThreatIntelligence
- dataTypes:
- ThreatIntelligenceIndicator
connectorId: ThreatIntelligenceTaxii
- dataTypes:
- SecurityEvent
connectorId: SecurityEvents
- dataTypes:
- SecurityEvents
connectorId: WindowsSecurityEvents
- dataTypes:
- WindowsEvent
connectorId: WindowsForwardedEvents
severity: Medium
triggerThreshold: 0
kind: Scheduled
queryPeriod: 14d
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/EmailEntity_SecurityEvent.yaml
query: |
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let emailregex = @'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$';
ThreatIntelligenceIndicator
| where TimeGenerated >= ago(ioc_lookBack) and ExpirationDateTime > now()
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true
//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 (
(union isfuzzy=true
(SecurityEvent
| where TimeGenerated >= ago(dt_lookBack) and isnotempty(TargetUserName)
//Normalizing the column to lower case for exact match with EmailSenderAddress column
| extend TargetUserName = tolower(TargetUserName)
// renaming timestamp column so it is clear the log this came from SecurityEvent table
| extend SecurityEvent_TimeGenerated = TimeGenerated
),
(WindowsEvent
| where TimeGenerated >= ago(dt_lookBack)
| extend TargetUserName = tostring(EventData.TargetUserName)
| where isnotempty(TargetUserName)
//Normalizing the column to lower case for exact match with EmailSenderAddress column
| extend TargetUserName = tolower(TargetUserName)
// renaming timestamp column so it is clear the log this came from SecurityEvent table
| extend SecurityEvent_TimeGenerated = TimeGenerated
))
)
on $left.EmailSenderAddress == $right.TargetUserName
| where SecurityEvent_TimeGenerated < ExpirationDateTime
| summarize SecurityEvent_TimeGenerated = arg_max(SecurityEvent_TimeGenerated, *) by IndicatorId, TargetUserName
| project SecurityEvent_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
EmailSenderName, EmailRecipient, EmailSourceDomain, EmailSourceIpAddress, EmailSubject, FileHashValue, FileHashType, Computer, EventID, TargetUserName, Activity, IpAddress, AccountType,
LogonTypeName, LogonProcessName, Status, SubStatus
| extend
timestamp = SecurityEvent_TimeGenerated,
AccountCustomEntity = TargetUserName,
IPCustomEntity = IpAddress,
HostCustomEntity = Computer,
URLCustomEntity = Url
description: |
'Identifies a match in SecurityEvent table from any Email IOC from TI'
name: TI map Email entity to SecurityEvent
tactics:
- Impact
version: 1.3.2
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"workspace": {
"type": "String"
}
},
"resources": [
{
"id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/2fc5d810-c9cc-491a-b564-841427ae0e50')]",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/2fc5d810-c9cc-491a-b564-841427ae0e50')]",
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
"kind": "Scheduled",
"apiVersion": "2022-11-01",
"properties": {
"displayName": "TI map Email entity to SecurityEvent",
"description": "'Identifies a match in SecurityEvent table from any Email IOC from TI'\n",
"severity": "Medium",
"enabled": true,
"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) and ExpirationDateTime > now()\n| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId\n| where Active == true\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(union isfuzzy=true\n(SecurityEvent\n| where TimeGenerated >= ago(dt_lookBack) and isnotempty(TargetUserName)\n//Normalizing the column to lower case for exact match with EmailSenderAddress column\n| extend TargetUserName = tolower(TargetUserName)\n// renaming timestamp column so it is clear the log this came from SecurityEvent table\n| extend SecurityEvent_TimeGenerated = TimeGenerated\n),\n(WindowsEvent\n| where TimeGenerated >= ago(dt_lookBack)\n| extend TargetUserName = tostring(EventData.TargetUserName)\n| where isnotempty(TargetUserName)\n//Normalizing the column to lower case for exact match with EmailSenderAddress column\n| extend TargetUserName = tolower(TargetUserName)\n// renaming timestamp column so it is clear the log this came from SecurityEvent table\n| extend SecurityEvent_TimeGenerated = TimeGenerated\n))\n)\non $left.EmailSenderAddress == $right.TargetUserName\n| where SecurityEvent_TimeGenerated < ExpirationDateTime\n| summarize SecurityEvent_TimeGenerated = arg_max(SecurityEvent_TimeGenerated, *) by IndicatorId, TargetUserName\n| project SecurityEvent_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,\nEmailSenderName, EmailRecipient, EmailSourceDomain, EmailSourceIpAddress, EmailSubject, FileHashValue, FileHashType, Computer, EventID, TargetUserName, Activity, IpAddress, AccountType,\nLogonTypeName, LogonProcessName, Status, SubStatus\n| extend\ntimestamp = SecurityEvent_TimeGenerated,\nAccountCustomEntity = TargetUserName,\nIPCustomEntity = IpAddress,\nHostCustomEntity = Computer,\nURLCustomEntity = Url\n",
"queryFrequency": "PT1H",
"queryPeriod": "P14D",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0,
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"Impact"
],
"alertRuleTemplateName": "2fc5d810-c9cc-491a-b564-841427ae0e50",
"customDetails": null,
"entityMappings": [
{
"fieldMappings": [
{
"identifier": "FullName",
"columnName": "AccountCustomEntity"
}
],
"entityType": "Account"
},
{
"fieldMappings": [
{
"identifier": "FullName",
"columnName": "HostCustomEntity"
}
],
"entityType": "Host"
},
{
"fieldMappings": [
{
"identifier": "Address",
"columnName": "IPCustomEntity"
}
],
"entityType": "IP"
},
{
"fieldMappings": [
{
"identifier": "Url",
"columnName": "URLCustomEntity"
}
],
"entityType": "URL"
}
],
"templateVersion": "1.3.2",
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/EmailEntity_SecurityEvent.yaml"
}
}
]
}