Let me first disqualify myself as an expert in this area, so YMMV
The way I read the article is that you need to have malware on your computer specifically looking for this weakness created by the Sony installer to get problems. So if you run a proper anti-virus/anti-malware software the probability of something going wrong would be low. So I would just follow the procedure and not worry too much. I've done my first update with this type of installer for the first time in 2010 and many times since then. But as they say ignorance is bliss
So, since the probability is not zero and the concequence might be too big for you (I don't store many propretary access codes on my computer, so I consider my risk low) maybe getting an old disconnected laptop in your household to do these updates completely avoids the risk.
Another thought is that if it would be a widespread problem the internet would be filled with many more burning stories vs. just this article which only describes the theoretical danger, but doesn't report anything about actual cases that went wrong, which would be strange for an unsafe type of software that's already in use for more then 8 years.
If others on here are more knowledgable about this problem I'm happy to be proven wrong so I can take better care next time I need to do a Sony firmware upgrade.