Certified Pre-Owned - TGTs requested with certificate authentication

Original query, unchanged.

let timeframe=1h;
SecurityEvent
| where TimeGenerated >= ago(timeframe)
| where EventID == 4768
| project TimeGenerated, Computer, TargetAccount, EventData=parse_xml(EventData)
| mv-apply d=EventData.EventData.Data on
(
  where d["@Name"]=="CertIssuerName"
  | project CIN=tostring(d["#text"])
)
| where not(isempty(CIN))
// <DECISION - 1>
// In some environments, we see a lot of certs starting with a sid and containing live.com. Comment out the next line if you have that as well.
//| where not(CIN startswith "S-1-")
// <DECISION - 2>
// If you're seeing a significant number of machine accounts, it might be due to 802.1X or SCCM. https://twitter.com/MagnusMOD/status/1407800853088591872?s=20.
// The following line allows you to filter out all endpoints. This does introduce a blindspot, and you need a custom function which provides data about (on-prem) AD machines.
// Alternatively, you can use DeviceInfo, if you're ingesting that data from MDE.
| parse CIN with "CN=" MachineName
//| join kind=leftouter  MyCustomLookupFunction on $left.MachineName == $right.CN
//| where not(OperatingSystem startswith "Windows 10")