Symantec documents several fake AV update email or website messages
QUOTE: A new clever way of social engineering spam is going around today that attempts to trick users into running malware on their computers. The methods malware authors are using include emails pretending to be from various antivirus software companies with an important system update required to be installed by the end user, along with attaching a fake hotfix patch file for their antivirus software. The email plays on end user concern over the lack of detection, especially in the face of the latest threats showcased in the media recently, such as the Cryptolocker Trojan. This type of social engineering entices users to open and install the hotfix without using much discretion as to what they may be actually installing.