Reset to factory condition.
When you log-in to google again it will behave like you have a new phone, and give options to re-install practically everything as before. 
I think it's unlikely a photo had a 'virus' contamination but it might have been corrupted i.e. an unreadable file.
That could happen if the phone was struggling to find enough processing power to write the file info correctly.

Setting the photo resolution to a lower option might help.
In the megapixel war they are all making ridiculously large files these days.
It should still be able to record quick enough.
Does it have a removable SD card, if so that could be cleared out and formatted or just try a different one.
If it does have one ideally set it to store pictures and video there, you can soon run out of space therwise,