Here is another interesting trick: save the virus in a password-protected ZIP or RAR file. Include the password in the e-mail, and use social engineering to convince users of opening it. Antivirus programs can not detect the virus, at least, not in its compressed form.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)
