Trend Micro is the latest security firm to warn about the threat of malware targeting the Apple Mac operating system (OS) and the iPhone platform.
It follows warnings by the likes of vendors Sophos and Kaspersky that Apple's increased market share could mean that criminals will see Mac computers as more of a potential target.
In Trend Micro's 2009 Forecast, the company predicted an increase in attacks against Apple Mac computers during the second half of this year.
Rik Ferguson, solutions architect at Trend Micro, said that this was due to simple economics the popularity of the Apple Mac OS was increasing at a faster rate than it has ever done before.
He said: "It's become a lot more mainstream, so it offers a greater return on investment [for the malware writers]."
The vendor also said the malware writers would be encouraged by the fact that the majority of Macs did not come with anti-virus software installed by default, unlike the majority of Windows-based PCs which do so.
Apple has been accused of sending mixed messages about whether Mac users needed to install anti-virus software on their systems. A post which suggested that Mac users install anti-virus was deleted from the Apple website, but it was revealed later that this wasn't a retraction and that Apple had already had this message up for some time previously.
Recently, a copy of iWork posted on BitTorrent sites was found to be infected with a trojan, but not before thousands of users had downloaded it. Others continue to download it, even though there are warnings not to.
"Users of non-mainstream OSs in general have over the years taken comfort in the security they have in being a minority base," added Ferguson.
"They haven't been a very large attack target until now, and that has led them to the conclusion that their OS' are safe."
Ferguson also believes that the iPhone has helped boost mobile internet use, drawing increased attention from criminals.
"The large target audience and the usability and acceptance of the mobile web is again creating a target where it didn't use to exist," he said.
Apple had not responded to our request for comment at the time of publication.
