PDF (Page Description Format) files are usually considered harmless to open. Unfortunately, a flaw has been found in PDFs, requiring an update to Adobe Reader and Acrobat software. This is apparently the first security vulnerability in PDFs since November 2000, when a hole was found in Adobe’s version 4 software.
To eliminate the risk, take one of the following three steps. (1) Rename Adobe’s eBook.api file, if you don’t use Adobe eBooks; (2) Install the Reader 6.0.2 upgrade; or (3) Upgrade Reader and Acrobat to version 7.0. We recommend upgrading to Reader 7, just released last month, which is reportedly much faster than Reader 6. How to upgrade
Security firm iDefense has posted a description of the problem and workarounds for it. More info
Blogger Jonathan Hardwick has posted an excellent guide to speeding up Reader 7.0 even more, including deleting a memory-resident file it installs. More info
Finally, AcroPDF.com released on Jan. 1 its new PDF Speedup 1.42, an excellent utility that supercharges Adobe Reader for you automatically. More info