A scareware programme known as 'Mac Defender' is currently causing an increasing number of Mac users woe by demanding payment to remove viruses it claims to have found on their machines.

The programme appears to automatically download to unprotected machines, exploiting the default 'open files after download' setting of most web browsers.

Although the user must provide an administrator name and password to install the bogus software, a 'significant number' of users seem to have done just that.

The software then autoruns, makes out like its scanning the Mac for viruses and asks users for credit card details in order to remove the viruses it claims to have found.

Mouldy Apple

Apple support staff have been instructed that: "AppleCare does not provide support for removal of the malware. You should not confirm or deny whether the customer's Mac is infected or not."

As well as Mac Defender, the malware also occasionally calls itself "Mac Protector" and "Mac Security", and is spreading through legitimate advertising networks and 'poisoned' Google searches.

Mac users should disable the 'open files after download' option in their browser settings to avoid accidentally installing the programme.

The Guardian reckons an organised gang is behind the scam, although it's not clear where the evidence for this supposition has come from.

Either way, it's a sad day for Mac users, many of whom thought themselves somewhat untouchable in the virus/malware arena.

Via ZDNet and The Guardian