If they got the file anywhere other than the Adobe site, it could very well be malicious.
In checking the Adobe FTP site, the installer file for that version of Reader is called AdbeRdr1011_en_US.dmg .
That's close to the same name as yours (not sure if you hand typed it in or not)
Thanks. The file is AdbeRdr1011_en_US.dmg. I typed it wrong the first time. Another family member was trying to open a .pdf file and got a message stating that he needed to update his Adobe Reader and this is the file he downloaded.
If the message was sent from Reader itself then it looks to be fine. Hard to say though without being there but chances are it's a good file if they were using Reader to open a PDF.
From the sounds of the actual issue, the Phishing email probably originated from within his email rather than on his Mac. Even though he's a Mac user, he should be running anti-virus and malware detecting applications. On mine I use Sophos anti-virus. Great stuff and free to boot.