I'm on a couple of computer forums and there are always posts about new exploits being found in the Adobe reader, many more than most people, I think, are ever aware of. Because it's such a popular product, it is targeted by the malware creators. Most of the people on those forums use alternative viewers because of that.
I've got the Adobe reader on my computer but I no longer use it as my default PDF viewer. I use the freeware PDF-XChange Viewer, and have done so for a few years. Foxit is also a good one.
PDF-XChange Viewer:
http://www.tracker-software.com/prod...xchange-viewer