svchost.exe is literally what the name implies. It's a generic service host. You pass it a dll and an entrypoint (via command line arguments and registry keys) and it runs it.

You should look at which thing it's actually running to see what's using all your CPU.

Some articles detailing what it does and how it works: [1] https://nasbench.medium.com/demystifying-the-svchost-exe-pro... [2] https://pusha.be/index.php/2020/05/07/exploration-of-svchost... [3] https://blog.didierstevens.com/2019/10/29/quickpost-running-...