Adobe have confirmed that Hackers are distributing Malware with the aid of Free adobe license key.
Mail with Titles reads as ‘Download your adobe software, ‘Download your license key’ ‘Thank you for your order’, ‘Your order has been processed’, ‘Free adobe license key’ and the body reads something like “Hello. Thank you for buying Creative Suite 6 Master Collection software. Your Adobe License key is in attached document below. Adobe Systems Incorporated.”

Adobe confirmed that these are fraud and fake emails which are no way related to any of the product of adobe, More over these emails contains Malware reported as a variant of Kuluoz Trojan. 
Once downloaded these Malware downloads other malicious elements such as ZeroAccess and Fake Antiviruses. and can damage the computer.

Adobe is aware of reports that a phishing campaign is underway involving malicious email purporting to deliver license keys for a variety of Adobe offerings. Customers who receive one of these emails should delete it immediately without downloading attachments or following hyperlinks that may be included in the message.  For more information on protecting yourself from phishing attempts, please visit, Adobe Product Security Incident Response Team (PSIRT) said in their blog post.

Simple steps can be followed to be safe from phishing emails, follow the steps given in the Image below, and stay safe.