I tested Avast-Home at http://www.webmail.us/testvirus where 27 harmless virii are ready to be sent to your own email address. I send them all, and tell you what? 24 were detected and could easily be removed. However, three got through Avast and made it to my OE-mailbox! As they were numbered it is easy to detect which came through, the nrs 4, 14 and 27. :o
Nr. 4 used UU-encoding;
Nr 14 was sent in a Microsoft TNEF file (winmail.dat);
nr 27 was the same Eicar virus within a ZIP file that has been manipulated to evade detection by some anti-virus software by changing the uncompressed size to zero within the ZIP file headers.
The conclusion was some of the test samples, especially those in archive file attachments (which are inert unless activated) and you also have to open an attachment from an unknown email source (common sense applies, you wouldn’t do it, right?). avast also has defence in depth, you aren’t only relying on it being caught in a zip attachment, there is also the standard shield (on-access) provider when you try to save the zip to your HDD or try to open the zip file.
