Firefox Users Beware: A Trojan Just for You!

One of the great things about Firefox is that it is relatively secure and does not suffer from many of the security flaws and holes that come prepackaged with Internet Explorer. And given its smaller market share, malicious hackers have generally ignored it. However, with Firefox’s steady and increasing popularity, as well as its broad support for plug-ins and 3rd-party extensions, an enterprising hacker has just created a specially designed trojan for unsuspecting users.

Earlier this week, BitDefender identified a malicious trojan by the name of Trojan.PWS.ChromeInject.A. Once it gains access to a system, it registers itself as the Greasemonkey add-on in Firefox’s add-on directory. And then it wreaks havoc by searching your hard drive for sensitive data such as usernames and passwords, which it then sends to an external website. (Note: The Greasemonkey add-on in Firefox’s add-on directory, also pictured below, is trojan-free and safe to use.)

If you are wondering how you might be infected by the trojan, it is unlikely that you will get it by downloading it directly from a website. Instead, it is often delivered onto an already compromised computer system by other malware. And once it has infected a computer, it will work every time Firefox is started, with or without your knowledge.

And now that one trojan has been able to exploit Firefox and stay hidden within it, it is likely that other trojan and malware authors will mimic this approach. So it is important to be careful when downloading anything online. In fact, we’d suggest only downloading from well-known and trusted sources. And finally, it is also important to keep your anti-virus software up-to-date and conduct regular full-system scans.