I'm pretty sure that, according to textbook definition, you are.
A while ago I got an infection myself. I had been using a freeware disk defragmenter for years without problems. I had also disabled automatic updates. But one day the software updated itself automatically anyway and hijacked my homepage and some other things.
Any software company you trust today could be taken over by evil malware distributors, or whatever they like to call themselves, and you could be infected by no fault of your own.
Don't think you are immune to the dangers of the internet.
BTW it was IOBit Smart Defrag, and I'm never using any of their software ever again.