2021-1675 - PrintNightmare KQL - MDE

2021-1675-spooler-imageloads.kql

let serverlist=DeviceInfo
| where DeviceType != "Workstation"
| distinct DeviceId;
let suspiciousdrivers=DeviceImageLoadEvents
| where DeviceId in (serverlist)
| where FolderPath startswith @"c:\windows\system32\spool\drivers"
| distinct SHA1
| invoke FileProfile(SHA1, 1000) 
| where GlobalPrevalence < 50 and IsRootSignerMicrosoft != 1 and SignatureState != "SignedValid";
suspiciousdrivers
| join kind=inner (DeviceImageLoadEvents
| where DeviceId in (serverlist)
| where FolderPath startswith @"c:\windows\system32\spool\drivers") on SHA1
| where InitiatingProcessFileName != "ccmexec.exe"
// Optionally filter for only the print spooler to load the driver to make it specific to this attack
//| where InitiatingProcessFileName == "spoolsv.exe"