Security experts have discovered two new worms targeting Apple users using Mac OS X.
Sophos found an updated version of the Tored worm, which it had earlier reported back in May, though it was thought too amateurishly made to cause real problems.
The real threat comes from a second worm Sophos calls OSX/Jahlav-C, which was first noted by Jerome Segura, a security analyst for ParetoLogic.
OSX/Jahlav-C works by using a video promising hardcore porn, which pops up a message asking the user to install an ActiveX component.
Installing the program - which is described as being "insistent" - will result in the download of a Trojan horse that can hand over control of the computer to a hacker.
The threat of Mac malware has been a hot topic for some time now, and in April another security vendor in Symantec saw the first example of a Mac botnet, which carried out Denial of Service attacks through Mac computers.
Sophos security analyst Graham Cluley suggested on his blog that there could be some Apple users who had switched from Windows to avoid the spyware, pop-ups and virus attacks resulting from searching for porn.
He said: "If they think they are immune from attacks they're making a mistake."
"We're seeing more attacks against Mac users all the time, with hackers planting bear-traps that work out if you're visiting their page on a Windows or Mac computer, and deliver the appropriate malicious payload accordingly," he added.
It comes after Apple dedicated a whole page to the security features of its new Snow Leopard operating system, as well as a disclaimer that said that no system was 100 per cent immune from every threat, and that anti-virus software could offer additional protection.
Sophos also offered a humorous video guide on how Apple users could be trapped surfing for porn on the web.
