Who did you get this "notice" from? Was it in an email?
What AV do you have?
I was using Reader to view my classes study guides for finals, and upon opening the first review, I got a notice to update Reader from Adobe. I click "Update" and wait a minute, it loads and than click "Install" and at 50% my Anti-virus tells me there is a trojan attached...
There was no e-mail notice (not fooled by that)
Notice came directly from with-in reader
AV is Comodo Antivirus Advanced 2012
It's most certainly a false positive coming from your AV. Happens a lot.