Looking at your list of security programs and techniques one thing I noticed you lack is anti-exploit protection and other means of making drive-bys les likely. This may have been what the "you are vulnerable to a malicious website" result meant. You can secure yourself against drive-by (also called exploit and when delivered to other sites via adverts called malvertising) infections by running malwarebytes anti-exploit (there is a free version) and for extra security using firefox as your browser with the noscript extension installed, combined these should mean that you can no longer be infected by drive-by methods, although use of noscript may take a few weeks getting used to, after which it will have "learnt" the settings you like and won't seem strange at all. This sort of protection, against these sort of infections is getting mroe important day by day as more malware is starting to be delivered via dangerous adverts (which can appear in the corners of legitimate sites including major news sites and other reputable ones) and exploit pages, thesedays you don't have to download a dodgy file to get infected, you can be infected just by seeing an tiny advert on the corner of a page.
Post #4:"Something else, but very important: do you make regular system backups?"
Well said Didier Stevens, I just wanted to highlight the importance of this because even with near perfect security IF something DOES hapen you need something to fall back on. Make sure to have both backups of files (make these regularly, at the end of each day backup any iles you edited that day) and backups of your whole system (system images) which allow you to restore the whole system (the operating system, your choice of settings for the operating system, all your installed programs, and the settings you have for each of them...) to an earlier point in time, you don't need to make images so often, but you need to make sure to have several of them made at a time when you know the system was utterly clean of infections, running as you like it and had all the programs you use installed on it.
Edited by rp88, 22 September 2015 - 02:23 PM.
Back on this site, for a while anyway, been so busy the last year.
My systems:2 laptops, intel i3 processors, windows 8.1 installed on the hard-drive and linux mint 17.3 MATE installed to USB