TI Map URL Entity to Syslog Data

Original query, unchanged.

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
ThreatIntelligenceIndicator
// Picking up only IOC's that contain the entities we want
| where isnotempty(Url)
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true and ExpirationDateTime > now()
// 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 (
  Syslog
  | where TimeGenerated >= ago(dt_lookBack)
  // Extract URL from the Syslog message but only take messages that include URLs
  | extend Url = extract("(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\\(\\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)", 1,SyslogMessage)
  | where isnotempty(Url)
  | extend Syslog_TimeGenerated = TimeGenerated
) on Url
| where Syslog_TimeGenerated < ExpirationDateTime
| summarize Syslog_TimeGenerated  = arg_max(Syslog_TimeGenerated , *) by IndicatorId, Url
| project timestamp = Syslog_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, SyslogMessage, Computer, ProcessName, Url, HostIP