In that folder located malware detected by MSE. I think only malware for transferring into Microsoft Malware Protection Center, cuz quarantine is located in %ProgramData%\Microsoft\Microsoft Antimalware\Quarantine. It's safe to delete.
Why these rules don't include in CCleaner by default?
Add please:
[MRU Photoshop FileList*]
LangSecRef=3021
Detect=HKLM\SOFTWARE\Adobe\Photoshop
Default=False
RegKey1=HKCU\Software\Adobe\MediaBrowser\MRU\Photoshop\FileList