Microsoft COVID-19 file hash indicator matches

let dt_lookBack = 1h;
let covidIndicators = (externaldata(TimeGenerated:datetime, FileHashValue:string, FileHashType: string, TlpLevel: string, Product: string, ThreatType: string, Description: string )
[@"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Feeds/Microsoft.Covid19.Indicators.csv"] with (format="csv"));
let fileHashIndicators = covidIndicators
| where isnotempty(FileHashValue);
// Handle matches against both lower case and uppercase versions of the hash:
(fileHashIndicators | extend FileHashValue = tolower(FileHashValue)
| union (fileHashIndicators | extend FileHashValue = toupper(FileHashValue)))
// 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 (
   CommonSecurityLog | where TimeGenerated >= ago(dt_lookBack)
   | where isnotempty(FileHash)
   | extend CommonSecurityLog_TimeGenerated = TimeGenerated
   )
on $left.FileHashValue == $right.FileHash
| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by FileHashValue
| project CommonSecurityLog_TimeGenerated, FileHashValue, FileHashType, Description, ThreatType,
SourceIP, SourcePort, DestinationIP, DestinationPort, SourceUserID, SourceUserName, DeviceName, DeviceAction,
RequestURL, DestinationUserName, DestinationUserID, ApplicationProtocol, Activity
| extend AccountName = tostring(split(SourceUserName, "@")[0]), AccountUPNSuffix = tostring(split(SourceUserName, "@")[1])
| extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)

relevantTechniques:
- T1204.002
name: Microsoft COVID-19 file hash indicator matches
requiredDataConnectors:
- dataTypes:
  - CommonSecurityLog
  connectorId: CefAma
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: SourceUserName
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: DeviceName
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: HostNameDomain
  entityType: Host
- fieldMappings:
  - identifier: Address
    columnName: SourceIP
  entityType: IP
- fieldMappings:
  - identifier: Value
    columnName: FileHashValue
  - identifier: Algorithm
    columnName: FileHashType
  entityType: FileHash
triggerThreshold: 0
id: 2be4ef67-a93f-4d8a-981a-88158cb73abd
tactics:
- Execution
version: 1.3.6
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/PaloAlto-PAN-OS/Analytic Rules/FileHashEntity_Covid19_CommonSecurityLog.yaml
queryPeriod: 14d
kind: Scheduled
queryFrequency: 1h
severity: Medium
status: Available
description: |
    'Identifies a match in CommonSecurityLog Event data from any FileHash published in the Microsoft COVID-19 Threat Intel Feed - as described at https://www.microsoft.com/security/blog/2020/05/14/open-sourcing-covid-threat-intelligence/'
query: |
  let dt_lookBack = 1h;
  let covidIndicators = (externaldata(TimeGenerated:datetime, FileHashValue:string, FileHashType: string, TlpLevel: string, Product: string, ThreatType: string, Description: string )
  [@"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Feeds/Microsoft.Covid19.Indicators.csv"] with (format="csv"));
  let fileHashIndicators = covidIndicators
  | where isnotempty(FileHashValue);
  // Handle matches against both lower case and uppercase versions of the hash:
  (fileHashIndicators | extend FileHashValue = tolower(FileHashValue)
  | union (fileHashIndicators | extend FileHashValue = toupper(FileHashValue)))
  // 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 (
     CommonSecurityLog | where TimeGenerated >= ago(dt_lookBack)
     | where isnotempty(FileHash)
     | extend CommonSecurityLog_TimeGenerated = TimeGenerated
     )
  on $left.FileHashValue == $right.FileHash
  | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by FileHashValue
  | project CommonSecurityLog_TimeGenerated, FileHashValue, FileHashType, Description, ThreatType,
  SourceIP, SourcePort, DestinationIP, DestinationPort, SourceUserID, SourceUserName, DeviceName, DeviceAction,
  RequestURL, DestinationUserName, DestinationUserID, ApplicationProtocol, Activity
  | extend AccountName = tostring(split(SourceUserName, "@")[0]), AccountUPNSuffix = tostring(split(SourceUserName, "@")[1])
  | extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)  
triggerOperator: gt

{
  "$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/2be4ef67-a93f-4d8a-981a-88158cb73abd')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/2be4ef67-a93f-4d8a-981a-88158cb73abd')]",
      "properties": {
        "alertRuleTemplateName": "2be4ef67-a93f-4d8a-981a-88158cb73abd",
        "customDetails": null,
        "description": "'Identifies a match in CommonSecurityLog Event data from any FileHash published in the Microsoft COVID-19 Threat Intel Feed - as described at https://www.microsoft.com/security/blog/2020/05/14/open-sourcing-covid-threat-intelligence/'\n",
        "displayName": "Microsoft COVID-19 file hash indicator matches",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "SourceUserName",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "DeviceName",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "HostNameDomain",
                "identifier": "DnsDomain"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SourceIP",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "FileHash",
            "fieldMappings": [
              {
                "columnName": "FileHashValue",
                "identifier": "Value"
              },
              {
                "columnName": "FileHashType",
                "identifier": "Algorithm"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/PaloAlto-PAN-OS/Analytic Rules/FileHashEntity_Covid19_CommonSecurityLog.yaml",
        "query": "let dt_lookBack = 1h;\nlet covidIndicators = (externaldata(TimeGenerated:datetime, FileHashValue:string, FileHashType: string, TlpLevel: string, Product: string, ThreatType: string, Description: string )\n[@\"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Feeds/Microsoft.Covid19.Indicators.csv\"] with (format=\"csv\"));\nlet fileHashIndicators = covidIndicators\n| where isnotempty(FileHashValue);\n// Handle matches against both lower case and uppercase versions of the hash:\n(fileHashIndicators | extend FileHashValue = tolower(FileHashValue)\n| union (fileHashIndicators | extend FileHashValue = toupper(FileHashValue)))\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   CommonSecurityLog | where TimeGenerated >= ago(dt_lookBack)\n   | where isnotempty(FileHash)\n   | extend CommonSecurityLog_TimeGenerated = TimeGenerated\n   )\non $left.FileHashValue == $right.FileHash\n| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by FileHashValue\n| project CommonSecurityLog_TimeGenerated, FileHashValue, FileHashType, Description, ThreatType,\nSourceIP, SourcePort, DestinationIP, DestinationPort, SourceUserID, SourceUserName, DeviceName, DeviceAction,\nRequestURL, DestinationUserName, DestinationUserID, ApplicationProtocol, Activity\n| extend AccountName = tostring(split(SourceUserName, \"@\")[0]), AccountUPNSuffix = tostring(split(SourceUserName, \"@\")[1])\n| extend HostName = tostring(split(DeviceName, \".\")[0]), DomainIndex = toint(indexof(DeviceName, '.'))\n| extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [
          "T1204.002"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Execution"
        ],
        "techniques": [
          "T1204"
        ],
        "templateVersion": "1.3.6",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}