"svchost.exe" is a part of windows that runs services. Services are things that runs in the background, the audio playback service, printer service, networking service, etc... Basically it's mainly essential windows stuff plus services added by other software.
Html will never deal with that file, and in fact cannot access it in most browsers, let alone with javascript. But that isn't javascript, it's vbscript which is a windows thing.
Anyways C2 does not generate that stuff in it's exported html, which means something on your pc is putting that in the file. It's probably a virus/tojan/spyware/etc of some kind infecting your pc. That html probably tries to run something on your computer that's encoded in that hexadecimal string. Good news is it probably only does something if run from iexporer. Well, if you can call that good news.
Your solution is to get an antivirus to clean your computer, and/or have someone tech savy that you know help you.