For years, Apple's computers have been considered safer than Windows PCs because hackers were writing malicious software for the Windows operating system rather than paying attention to Apple's OS X. However, as Apple continues to grow and OS X computers become increasingly commonplace, viruses and malware that target OS X are also going to become more common. With this in mind, Mac users need to know how to tell whether their computers have been hacked or infected, as well as how to deal with an attack after it is discovered.
Where anti-virus software is more or less essential for anyone with a Windows computer, it remains a rarely used option for Mac users. As PC Magazine notes, the opinions on anti-virus software for Macs are mixed, and some Apple Store workers advise against using it. Most viruses that hit the Mac are too new for OS X anti-virus programs to have a comprehensive list of definitions, and anti-virus software can end up hogging the Mac's RAM and CPU without ever doing anything.
If you think your computer has been hacked and want to scan your Mac for malicious software, though, there are several anti-virus programs available on the Web. PC Mag recommends both ClamXav and Avast for free system scans and ongoing protection. Bitdefender is another free popular choice that you can get at the App Store.
The Genius Bar
If your Mac is exhibiting behavior that you think might be the sign of a virus — such as slow and sluggish performance, a prevalence of pop-ups and other advertisements or seemingly random resets, take it to the nearest Apple Store for help from a technician at the Genius Bar.
Apple Store experts can determine if your problem is a virus or if the problem is related to hardware, apps or the OS X operating system itself. The most common sources of malware on a Mac are software downloaded from outside of the App Store, pirated content or plugins requested for installation on random sites. If you can't recall downloading or installing anything questionable, there's a good chance you're facing a hardware or operating system problem. In any case, it's a good idea to get a second opinion — especially if you are considering wiping your hard drive and reinstalling the operation system to deal with a virus or hack.
Check the Applications Folder
Much of the most common malware for OS X is easy to find and even easier to remove. According to CNET, some of the most common Mac hacks are fake anti-virus programs such as MacDefender, Mac Security and Mac Protector. Getting rid of these pesky programs is as simple as opening your Applications folder, finding the fake anti-virus program and dragging it into the trash.