I specifically insist on deleting it (perhaps, the whole C:\ProgramData\Microsoft\Windows Defender\Platform folder), because it eats a lot of system resources while being turned off through several regedit tweaks and inside the Security Center itself. A program called Unlocker did absolutely nothing. My Windows 10 version is Home, so I'm unable to use Group Policy Editor. I also tried to use PsExec, but it could not help me. Applying all kinds of Security properties did not work either.
Edit: thank you for your help, but the registry trick is blocked by the system. NoDefender website is not serving the app anymore, and I cannot find it in Google, web archive refuses to give me a snapshot. I will try to use my Ubuntu to rename the folder.
Edit 2: renaming the folder using Ubuntu worked like a charm
