One of the top positives of using a Mac OS computer is that there are a remarkably smaller number of viruses out there compared with those affecting PCs. A lot of this has to do with viruses and malware largely being built to attack businesses. Since more businesses use Windows than MACs - by about a 90% share - hackers and cybercriminals are a lot more dedicated to infecting PCs. 

But even with that lopsided statistic at play, Mac OS users still have one of the nastiest viruses to contend with: the Flashback Trojan Virus.

History of the Flashback Trojan Virus
The Flashback Trojan Virus has been plaguing Mac users for seven years after its initial discovery in 2011. It originally took the guise of an installer for Adobe Flash Player, which is how it got its name. The installer rerouted users to a website where malicious code was launched. It would then use bots to harvest user passwords and other information from web browsers and communication programs like Skype. Officials estimated 600,000 computers were infected with Flashback by 2012. Flash’s creator, Oracle, fixed the vulnerability by Valentine’s Day 2012, but the Flashback Trojan continues to persist, mutating into several other forms.

Removing the Flashback Trojan Virus from your Mac
Before we dive into the various ways to remove this virus from you Mac, the best way to keep any kind of computer in good health and virus-free is to employ antivirus software. There are numerous offerings for any budget, operating system, or specific needs. Some of the best are reviewed by Safetydetective and can give you the positives and negatives of several leading brands of antivirus software, including which work best for Macintosh products. You can check out  Kaspersky antivirus program that is designed to protect users from malware and is primarily designed for computers running Microsoft Windows and macOS.

Your first step should be to confirm that the Flashback Trojan Virus is actually infecting your Mac. There are two great resources for this.

The first is to visit F-Secure’s Flashback detection site and download the app that will scan your Mac for the virus. It has instructions on removal if the Trojan is detected on your computer.

Security firm Symantec also has a standalone tool just for addressing the Flashback Trojan Virus. 
Remarkably, most Macs have a built-in tool that can be used to wipe your system of the Flashback Trojan Virus. It is a piece of software called Terminal and can be found in your Utilities folder inside of the Applications folder. An easy way to access it is to search for “Terminal” using the Spotlight feature.

Once you’ve found the folder, you can copy and paste the following code strings into the Terminal window.

They are:

defaults read /Applications/ LSEnvironment
defaults read /Applications/ LSEnvironment
defaults read ~/.MacOSX/environment DYLD_INSERT_LIBRARIES

If your system is not infected, you will get a message saying that the domain/default pairs “does not exist.” If the virus is on your computer, the patch will split up and point where the virus is inhabiting your system.
To remove them completely, locate the files that appear when you run the commands listed above, then delete them.