step 0 is prevention:
- never download or install shady binaries that you don't know the source of and don't trust.
- always make sure you have real software by verifying their digital signature if possible
- if you have to run a shady application then use a sandbox so that in case it contained anything malicious it wouldn't infect your computer.
- never visit shady website
- and as the last line of defense if you are on a closed source OS such as Windows or Mac you can install a good anti virus.
if you are already infected
best solution would be formatting the hard disk and reinstalling the OS but since that is hard you can install a good anti virus or use a rescue disk to scan and try to remove it.
detecting this type of malware is easy since they have to use excessive amount of computing power so the symptoms are obviously increased CPU or GPU usage, hearing the fan sound (if your fan speed is adjusted according to usage),...
How do you think, would it better to buy a clean new processor to skip many steps and start mining using a new PC or make a cleaning?
Cleaning will always be needed, even if we buy a good processor there will still be cleaning that must be done at least once every 2 weeks or once a month, this is also to maintain the quality of the processor and things that can worsen the work of the processor if we do not do cleaning or maintanance.
Because an electronics will also always have a time to rest