TI map Domain entity to PaloAlto

Requête originale, sans modification.

let dt_lookBack = 1h;  // Duration to look back for recent logs (1 hour)
let ioc_lookBack = 14d;  // Duration to look back for recent threat intelligence indicators (14 days)
// Create a list of top-level domains (TLDs) in our threat feed for later validation of extracted domains
let list_tlds = 
    ThreatIntelligenceIndicator
    | where isnotempty(DomainName)
    | where TimeGenerated >= ago(ioc_lookBack)
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
    | where Active == true and ExpirationDateTime > now()
    | extend DomainName = tolower(DomainName)
    | extend parts = split(DomainName, '.')
    | extend tld = parts[(array_length(parts)-1)]
    | summarize count() by tostring(tld)
    | summarize make_list(tld);
let Domain_Indicators = 
    ThreatIntelligenceIndicator
    // Filter to pick up only IOC's that contain the entities we want (in this case, DomainName)
    | where isnotempty(DomainName)
    | where TimeGenerated >= ago(ioc_lookBack)
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
    | where Active == true and ExpirationDateTime > now()
    | extend TI_DomainEntity = DomainName;
Domain_Indicators
    // Join with CommonSecurityLog to find potential malicious activity
    | join kind=innerunique (
        CommonSecurityLog
        | extend IngestionTime = ingestion_time()
        | where IngestionTime > ago(dt_lookBack)
        | where DeviceVendor =~ 'Palo Alto Networks'
        | where DeviceEventClassID =~ 'url'
        // Uncomment the line below to only alert on allowed connections
        // | where DeviceAction !~ "block-url"
        // Extract domain from RequestURL, if not present, extract it from AdditionalExtensions
        | extend PA_Url = coalesce(RequestURL, "None")
        | extend PA_Url = iif(isempty(PA_Url) and AdditionalExtensions !startswith "PanOS", extract("([^\"]+)", 1, tolower(AdditionalExtensions)), trim('"', PA_Url))
        | extend PA_Url = iif(PA_Url !in~ ('None', 'http://None', 'https://None') and PA_Url !startswith "http://" and PA_Url !startswith "https://" and ApplicationProtocol !~ "ssl", strcat('http://', PA_Url), PA_Url)
        | extend PA_Url = iif(PA_Url !in~ ('None', 'http://None', 'https://None') and PA_Url !startswith "https://" and ApplicationProtocol =~ "ssl", strcat('https://', PA_Url), PA_Url)
        | extend Domain = trim(@"""", tostring(parse_url(PA_Url).Host))
        | where isnotempty(Domain)
        | extend Domain = tolower(Domain)
        | extend parts = split(Domain, '.')
        // Split out the top-level domain (TLD) for the purpose of checking if we have any TI indicators with this TLD to match on
        | extend tld = parts[(array_length(parts)-1)]
        // Validate parsed domain by checking TLD against TLDs from the threat feed and drop domains where there is no chance of a match
        | where tld in~ (list_tlds)
        | extend CommonSecurityLog_TimeGenerated = TimeGenerated
    ) on $left.TI_DomainEntity == $right.Domain
    | where CommonSecurityLog_TimeGenerated < ExpirationDateTime
    // Group the results by IndicatorId and Domain and keep only the latest CommonSecurityLog_TimeGenerated
    | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, Domain
    // Select the desired fields for the final result set
    | project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, PA_Url, Domain, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DeviceAction, DestinationIP, DestinationPort, DeviceName, SourceIP, SourcePort, ApplicationProtocol, RequestMethod, Type, TI_DomainEntity
    // Add a new field 'timestamp' for convenience, using the CommonSecurityLog_TimeGenerated as its value
    | extend timestamp = CommonSecurityLog_TimeGenerated