Historically viruses, trojans and malware have been terms that were only spoken in relation to Windows,Intel-based PCs. Now it would seem Mac computers will have the same security concerns going forward and are no longer immune to hackers installing malicious software on a users system.

A new widespread virus has been targeting Mac users over the past couple weeks. The trojan, known as Flashback or Fakeflash, has been infecting Apples’ PCs with malware that uses the victims machine to make fake clicks on the attackers Pay-Per-click advertising program. This puts money in the attackers pocket because it appears to the advertisers that the hits are coming from a legitimate potential customer. Of course once the attacker has the malware on the victims machine they can tell it to do what ever they want.

The virus received its name because some users would see a pop up window telling them to update Adobe Flash and type in their password. Once they clicked on the window, the malware would be installed on their system. Many users however, just visited a website and the virus was installed, a technique known as a ‘drive-by download’.

The Flashback virus doesn’t specifically attack the Mac operating system, instead it exploits a hole in Java in order to take control of the victims machine. Apple has released a patch which closes that loophole at http://support.apple.com/downloads/ the specific patch is called Java for Mac OS X 10.6 Update 7 and it’s located at – http://support.apple.com/kb/DL1516.

If you’re unsure if you have been infected there are a couple online tools to check. A security firm has reverse engineered the Flashback virus and is able to see the data being sent from infected machines. You can check their online tool here – http://public.dev.drweb.com/april/.

If you have been infected with the Flashback virus several anti-virus programs do have ways to eliminate it from your machine. If you are very tech savvy there are was to identify and remove the virus manually and they are detailed here – http://www.f-secure.com/weblog/archives/00002336.html.

Last year there was another widespread attack on Mac computers when the Mac Defender virus was released by hackers. Even though Mac Defender was less widespread and not as complex than the current threat, it still took Apple almost a month after the virus’ discovery to issue a fix. Experts say Flashback or Fakeflash is far more sophisticated and so far has infected more than 600,000 machines worldwide.

In the past Apple has had a very low market share in the PC sector. Twenty years ago it was all the way down around 3%. But it has been steadily increasing especially with popularity of the iPhone and iPod making consumers more aware of Apple’s products and giving them an increased willingness to connect all their devices. Now that Apple’s market share has increased to over 12%, it makes them a much juicier target for criminals and hackers.

It now looks like going forward Apple will have to have the same security concerns and response readiness that Microsoft has had to endure for so long. They will certainly have to respond to new threats a lot quicker than they did with the Mac Defender problem if they want to remain in the PC business.