svchost is a privileged windows NT process.
You sound like you like trouble shooting, download SVCHOST VIEWER and PROCESS EXPLORER from Microsoft. Svchost may be from codeplex.
Are you using windows 7 or windows 8? Windows 7 you can end much more services and "blackvipers" guide is really good for windows 7.
If it is a problem svchost a program called "Freefixer" Has helped me end those nasty suckers.
People who know how to give you svchost virus's are rather cluey. I suspect, you have a simple botnet infected machine. They used to be rather persistant and hard to get rid of like gum in ones hair, but now a days theyre much smaller in numbers, and unless you're using a xeon workstation or an equally high end computer on an amazing fibre connection you can most likely rid that without damaging your windows install.
What is happening is your computer is most likely being used to do what ever the hackers being paid for. Brazzer views, website votes, denial of service spamming, twitter friends, views ETC ETC.
These hackers would rather have the process going along unnoticed, and replicating that your system is only at 1% use when idle but secretly at 80-90% use. Thus my belief that your computer is either prime territory or not rootkit/firmware embedded with persistence modules.
Some people maybe be very interested in the data you are getting, not the passwords but from a law enforcement perspective these botnets are generally heavily encrypted and taking commands from an IRC channel. Capturing the packets, and as many usernames and passwords as possible can be detrimental to the money earnt by this hacker.
Don't get involved yourself, capture passively hackers can mess with your entire existence with the push of a button once rehearsed in their sploits.