1. Reset your firewall, so everything will be blocked.
2. Uninstall (if you can) all so-called Virus- and Malware- -Scanners. They do not scan. They 'imagine' passively what could be a malicious behaviour, by comparing fixed sets of general side-effects of viruses, worms, trojans and malware in general, known to be possible to possibly be identified in that manner. That manner is named heuristically.
3. Download and install exactly one tool: ClamAV. - Do a full scan and if possible just let it run, without using the machine, also cutoff the network, if possible (after ClamAV has all definitions and actual clones of real-probes of all kinds of malware downloaded to compare every thing that is in reach of your operating-system against it). - Read the assumingly 3-digits and up counting results contained in the report carefully, or - if you say it does not make any difference - just kill everything found. - Then plan a reinstall.
4. If you use Windows 10, you have malware on-board by default. If you use Windows Server, you don't. If you use a regular Windows 10, you have a regular part actively sucking any ressource at-will once the machine goes into idle, due to you not using it right now: That part is called Cortana, a data-mining-application that creates gigabytes of metadata to create a wholesome catalogue of any- and every- -thing that may be different in your use-case versus all other users, to help identify your every move and step. You do this freely. It is a feature. - If you do not like that: Run Windows 10 LTSB 2016 or LTSC 2019 or Windows Server 2016 or Windows Server 2019. Or any other Version before Cortana was implemented. There is no other way.
5. If you use Windows at all. Once the system goes idle, the whole system gets indexed in detail, which effectively has absolutely no positive effect at all. It steals your time, eats your ressources, creates catalogues of Meta-Data that will never be-used to any positive outcome .. at least for you; becuase Microsoft is happy if you still have that problem-reporting and automatical transmission of usage-samples and behaviour-indicators, system-logs and by-default-enabled free-sharing of all that information 'to better the services and experience Microsoft delivers you, by uisng their products. - If you do not want that, you can disable it in some versions and editions. It takes a steep learning curve tackled pragmatically in a unreasonable amount of time and you will have no guarantee that it will stay way. On the contrary if you use windows Updates you have the guarantee, that Microsoft will contain patches via Windows Update and execute them on your machine without your consent, to reset your manually disablement of all those indexing and reporting, services, because it was taught that disabling those is malware-practice. You are the Malware. Happy disabling one more time. Until the next Update. - You have to decide. Microsoft says it is a feature.
6. Do not get even the slightest idea i would use this comment to emphasize hatred against Evil Corp. Microsoft. - I do not. I use their products. I do the extra million miles to keep it in reasonable limits, what happens to my systems. Will you?
7. Start at the top. Back to the beginning. You will read this step-by-step-tutorial, again. This is sarcastic. Because it is reality. I mean it.
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Hope it helps?!? Thanks for reading.