How can we tell if com surrogates are not a security issue?

I'm guessing this is the same Puter and same thing you've asked about twice before ??

When you see it in task manager right click on it and click properties. You should be able to tell from the Details tab and Digital signature if it has one. For further analysis you'd need to download and run System Explorer - Keep Your System Under Control

Since You've already run multiple Malware scanning tools and even resorted to a fresh install, IMHO, you either need to stop worrying about it or stop any practices you believe you might be getting Malware from