I have received a number of "Google Docs Share" virus/hacker emails of late. Read on ...
I found a post (HERE) that does a better job of describing the situation that I can. So I recommend reading that post. For that matter, just Google "google docs share virus email" (or something like that) and you'll find lots of posts on the topic.
Why am I writing about this? Just because in the last week I've received 3 or 4 emails from people I would generally trust, inviting me to click on a link in the email to view a Google Doc file they want to share with me.
Most of you already know this, but be VERY suspicious of any email you get that has an unknown attachment OR link. Even if it is from someone you trust. If you are unsure, contact the person (preferably some way other than email - since their email account may have been compromised) to make sure that the email they sent you is legitimate. Better safe than sorry!