Lumen TI IPAddress in CommonSecurityLog

Requête originale, sans modification.

let IPRegex = '[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}';
let dt_lookBack = 1h; // Look back 1 hour for CommonSecurityLog events
let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
// Fetch threat intelligence indicators related to IP addresses
let IP_Indicators = ThreatIntelIndicators
 | where TimeGenerated >= ago(ioc_lookBack)
 | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id
 | where IsActive == true and ValidUntil > now()
 | where SourceSystem == 'Lumen'
 | where ObservableKey == "ipv4-addr:value"
 | extend TI_ipEntity = ObservableValue
 | where ipv4_is_private(TI_ipEntity) == false and TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127.";
// Perform a join between IP indicators and CommonSecurityLog events
IP_Indicators
 | join kind=innerunique (
     CommonSecurityLog
     | where TimeGenerated >= ago(dt_lookBack)
     | extend MessageIP = extract(IPRegex, 0, Message)
     | extend CS_ipEntity = iff(isnotempty(SourceIP), SourceIP, DestinationIP)
     | extend CS_ipEntity = iff(isempty(CS_ipEntity) and isnotempty(MessageIP), MessageIP, CS_ipEntity)
     | extend CommonSecurityLog_TimeGenerated = TimeGenerated
 )
 on $left.TI_ipEntity == $right.CS_ipEntity
 | where CommonSecurityLog_TimeGenerated < ValidUntil
 | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by Id, CS_ipEntity
 | project timestamp = CommonSecurityLog_TimeGenerated, SourceIP, DestinationIP, MessageIP, Message, DeviceVendor, DeviceProduct, Id, Tags, ValidUntil, Confidence, TI_ipEntity, CS_ipEntity, LogSeverity, DeviceAction, Type