Using the simple "Quick'n Dirty" EICAR-GTUBE-Generator0.1 ( here last version ) I hided the EICAR signature inside a simple PDF file. Now let's give this pdf to AV and see what will happen.
Here the "fun" results (click to make it bigger):
Is it not weird that some AV leaders such as Microsoft, Avast and McAfee miss this easy control ?
Now, my question comes easily ... How can we be sure that recognize more complicated virus if they miss this easy signature control ?
More reading: Here, Here and Here