Google Threat Intelligence - Threat Hunting Hash

let ioc_lookBack = 1d;
_Im_FileEvent
| where isnotempty(Hash)
| extend lowerHash=tolower(Hash)
| join kind=inner (
ThreatIntelIndicators
| where ObservableKey contains 'file:hashes'
| where isnotempty(ObservableValue)
| where SourceSystem == "Google Threat Intelligence"
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id
| where IsActive == true and (isnull(ValidUntil) or ValidUntil > now())
| extend lowerHash=tolower(ObservableValue)
) on lowerHash
| project Hash=ObservableValue, HashType=extract("file:hashes.('[^']*')", 1, ObservableKey), Description=Data.description, Type, TimeGenerated