So my question is, what is the total mass of data of which you find the 800 missed malware samples plus those that are caught (which I suppose is a bigger number)? And how does that correlate to an average home user? Not to mention those who only use the Internet for banking and reading the leading tabloid sites? If I told about such numbers to my customers they'd sell their computers for fear of losing all their savings to Harry the Hacker.
Good question. So here is how it works...
The system is a cloud based malware protection platform, it operates on edge devices (firewalls and antispam systems). Files of interest are submitted (executables, documents etc). As a file is received a signature based pre-filter similar to VirusTotal runs over it (that's your 62 scanners). If malware is detected we stop there. Just a note these scanners are there to make the whole system more efficient, not as a way of measuring how good they are.
If the file comes out of that with no hits it is then submitted to 3 sandbox engines (in parallel). At the pre-filter stage we also check to see if we've seen this file before (ie had a sandbox hit earlier in the day). After the sandbox makes a decision we deliver a verdict back to the client. If a hit is found then the malware sample goes into processing to also generate a signature (to allow faster detection at the edge).
So the bit I am saying we see at least 800 new malware strands is when the sandbox engines pick something up. Those are 800 unique samples that just got past your major AV vendors. In August we hit 26000 total. Some AV vendors take days - weeks to get these signatures out, so 800 malware samples a day you are vulnerable might actually be 5 days worth (so 4000 or more you are currently vulnerable too).
End result is we had a signature in place for Wannacry 3 weeks before the big Wannacry hit. We had seen small (maybe test) samples of the malware the month before the big attack.
Things are bleak for the average home user. We're not interested in them, our product is priced a bit out of their range (but within small business) as are many leading security products.