Mikko of F-Secure argues that the ongoing security problems with Adobe Acrobat Reader, which is now the primary vector for malware having overtaken Microsoft Word sometime in 2009, is to do with fundamental issues with the PDF format itself.
Looking at the 756 page specification document (PDF format naturally) one finds details about how to embed all kinds of things from multimedia to executable JavaScript into PDF files.
So using an alternative to Adobe Acrobat Reader such as the Foxit Reader is not the solution as it is just as vulnerable due to including the same functionality as Adobe Acrobat Reader. There might be alternative PDF readers that simply render the documents without the additional functions but another secure workaround is to open them up in Google Docs.