Three types of viruses

Sophos blogger Chester Wisniewski provides a virus primer titled 3 types of "viruses" demystified. Here's a brief summary.

The word "virus" is used to encompasses all sorts of malware, but technically a virus is a parasitic application which can replicate itself but requires a carrier. "A virus cannot transport itself, but can copy itself into other files on your computer and hope you transfer the infected files to other computers."

"Worms," like Conficker, attack networks and are called "worms" because they exploit network vulnerabilities to infect other computers on the network or through the internet.

"Trojans" got the best name of the three. "Trojans are disguised as useful files or applications that entice you into executing them." But the user doesn't always necessarily have to execute them to activate them. They can latch onto vulnerable browsers, extensions, plug-ins, document readers, and audio video players while the user innocently visits a compromised website. Very scary.

Sophos wants you to buy their anti-virus software, and it's probably worth every penny. However, there are some free ones out there that have good reputations. AVG, for example, is the one I use, and so far I haven't had a problem. It probably helps to have a firewall, too, like the free ZoneAlarm.

Happy web surfing! And remember the important rules of life: Use virus protection and firewalls. Never shake a baby. Only you can prevent forest fires. And loose lips sink ships.

Comments

[ChetWisniewski]

Thanks George,

While I am not explicitly trying to sell anti-virus I appreciate your thoughtful post. As you recommend to your readers, the important thing is to properly protect your computer against malware. Whether you choose to pay for software or use many of the very capable free alternatives, I encourage everyone to take the threat seriously.

Sincerely,
Chester Wisniewski
Senior Security Advisor
Sophos Inc.

[Geo]

Thanks Chester,

I really enjoy the weekly Sophos email newsletter. Keep up the good work!