[@not free] The offer expired several hours earlier than posted. The “voucher” that was to be applied was “sosgiveaway16” but it will tell you that that voucher has expired. Not saying you are missing much, I have tried to test their software the last couple of times it has been offered (not just at SOS) but have NEVER been able to activate properly. I even went through several weeks (yes, weeks) of email correspondence with their customer/technical support before giving up. What was humorous is that the extended the license term (and made it a family multi-device) for me due to the inconvenience, which does absolutely no good since the key was always rejected on every computer tested.
The is a similar free produce that monitors & keeps software updated/patched called “Secunia PSI” which I do recommend. It does not provide malware scanning though.