How important is a good unpacker in a antivirus? I have learnt that KAV probably handles the most number of archives and packers and AVG handles very little. A antivirus weak in this area, will not be able to pick up malware if it's packed suitably. On the other hand, it's nearly impossible to handle all possible packers and the more you add, the slower the scanner gets? In any case, once the file executes, the onaccess scanner will get it anyway, so why worry? What do you think?