The Mac Trojan/Malware ‘MacDefender’ now calls itself ‘Mac Shield’.
The malware keeps changing names and looks but still is relatively the same as before. However it is still infecting loads of machines and is, in my opinion very dangerous; it lures users into providing sensitive financial information to thieves.
Sophos for Mac will remove it. (free) Get it here.
So will Virus Barrier Express from the Apple App Store; here. also free.