Know Thy Enemy: Common Computer Viruses and how to Avoid Them

Identifying Trojan Viruses

Perhaps the most common type of virus on the Internet is the Trojan virus. Like the legendary Trojan horse, this virus pretends to be something useful and desirable but is actually designed to either disrupt network processes or harvest information. Trojans can do any number of different things, including tracking keystrokes to gain access to passwords and personal information. These viruses used to be linked to illicit activities like illegal file sharing and pornography sites, but times have changed and they can now be found on reputable websites from time to time. Unfortunately, the only sure way to defeat a Trojan is to make sure it doesn’t infect your computer in the first place.

Protecting Against Trojan Viruses

Firewalls and virus protection software can help immensely in defeating Trojans, but the best start to protecting against this threat is making sure that each individual working on your network is well-informed about Internet security. Trojans often disguise themselves as downloadable executable files, often ending with the extension .exe, .vbs, and .bat. Never download these files from anonymous sources, and only run them if you have viewed the source’s security certificate. Be sure that everybody is also aware of Windows’ tendency to hide file extensions on the default settings. If you’re about to open “file.jpg” in an email attachment, be sure you’re not actually opening “file.jpg.exe.”

Identifying a Botnet

A botnet is a type of virus that turns your computer into something that a fraudster controls. By gaining access to a whole network, a botnet attack can potentially turn your entire business network into a puppet under the control of an unknown hacker. The hacker can then use any computer exposed to the attack to spread viruses, sent spam messages, or commit fraud. Many botnet attacks are unfortunately asymptomatic, but if your computer starts running slowly and has a lot of resources taken up by an unknown program, you might be a victim of such a virus. Frequent crashes can also be a sign that there is something amiss in your computer or network.

Protecting Against Botnet Viruses

You should practice the same precautions with botnet attacks that you do to defend against Trojan attacks. Additionally, many botnet viruses are spread by exploiting software vulnerabilities. As a result, it is very beneficial to keep all your software up to date at all times, as this will close many exploits and loopholes that hackers attack. Always keep your firewall up, especially if you have a business network. Employees who need remote access can be given a gateway to use that doesn’t compromise the firewall. Finally, make sure you are extra careful of flash drives. Botnet programs in a flash drive can spread to a computer they’re attached to, so only use a flash drive if it’s from a trusted source.

Identifying Scareware

Scareware is often used in conjunction with botnet or Trojan attacks. In this case, a warning pops up on your computer and tries to scare you into purchasing a product or providing personal information. Typical warnings include fake virus detection windows that direct you to purchase a “premium” edition of the software to remove the virus or warnings that you are in violation of some sort of federal law. Even clicking these windows to close them triggers the virus, and the virus often shuts down your Internet browser, preventing you from being able to find a removal solution online.

Protecting Against Scareware

It’s important to make sure that all users on your network are familiar with your virus protection software’s interface. This will minimize the chance that anybody will fall for a phony warning from a piece of scareware. In the case wh ere a virus of this type pops up, never click on the window, not even to close it. Usually, the best option is to reboot the computer, doing a hard shutdown if necessary, and either back up to a system restore point or run a virus scan immediately.

If anybody on your network contracts one of these viruses, it is a good idea to immediately change all passwords after the virus has been removed. By being aware of the dangers out there, you are forewarned and forearmed, hopefully giving you a better chance of avoiding these problems.