The spam e-mails that have been hitting inboxes recently have "Action required : Upgrade New Adobe Acrobat Reader For Your PC" in the subject line, and a link to a site that is not the official Adobe website:
Once the user falls for the scam and clicks on the Download button, he is asked to share some general information such as name and email address, choose a "membership plan" and, finally, to enter his credit card information.
According to Cloudmark, previous similar spam campaigns have been sent from legitimate email service providers such as Mailchimp and Exact Target, and this one has been misusing Silverpop.
Adobe has been warning users of the scam and urging them to delete the spam emails upon receipt. It is good to remember that the best thing to do if you want to buy or upgrade a piece of software is to visit the official developer's site by entering its URL directly into the browsers' address bar.