This is important information, malware attacks, in fact, all machines running Mac OS X. Mac Defender is the name of this crap, takes the form of a virus but it is nothing. Rather, this malware can infect your data and even stealing the bank details of the user. Suffice to say that if you have a Mac, then it is best not to install because it could cost you a lot of trouble.
Ordinarily, it is rather the machines running Windows that are the target of attacks but sometimes our Macs are also found in the crosshairs of evil developers. Mac Defender is not the first tool of its kind but it must admit that those who have programmed it right. Using several SEO techniques, they have managed to position it very well on some queries (eg Google Images) , and no doubt that many users have already fall into the trap.