There is also a feature where you can't find these e-mail viruses in the software whose purpose is to make sure that there are no virsues.
I'm unsure how to deal with もの in this sentence. I'm wondering whether "feature" is a valid translation (it certainly isn't one I've seen before).
Or perhaps I should treat ...ものもある more generally as "it is also the case that...". Would that work?
On a separate subject, I was surprised to see の中に used to describe the relationship between the virus and the anti-virus software. When I read this it sounds like the virus can't be found inside the anti-virus software rather than that the anti-virus software can't find the virus. If I'd tried to write this sentence I'd have written ソフトでは (with で having the "using/by means of" meaning). Am I wrong?