Are you a Zombie?

Have you checked in the mirror lately? You may have become a zombie without realising...

OK, so I'm having a little fun with the question but the truth is your computer may have become a zombie ready to be activated by remote command to start wreaking havoc. I'm talking about a type of infection which can occur whereby a piece of code called a "bot" gets installed on your PC (without your permission obviously) which is able to turn your computer into a zombie acting on behalf of a remote master.

So how likely is this? According to research done by Sophos, if an unprotected computer is attached to the internet there is a 50% chance of it becoming infected within 12 minutes...

So what do these things do? They are covert software items which typically "check in" to a control position on the internet to report they are ready for duty. Commands can be sent to them, typically for sending SPAM or participating in Distributed Denial of Service (DDOS) attacks. A DDOS attack is where many computers send requests for web pages or other services to a targeted web site. When too many requests come in a web server can be literally overwhelmed by the traffic. This means that no legitimate users of the site can get access.  There have been attacks done in this way which involved up to 60,000 zombies. These large scale networks of infected computers are referred to as "botnets" and it is possible for people to hire there services; reports are of botnets of up to 20,000 infected machines being offered for hire between $2,000 and $3,000.

Normally for a bot to be installed on a computer a virus infecting the machine opens an internet "port" (also called a back door) which then allows the bot to be installed. Once the bot is installed the machine is now a zombie.

So what do you do about it?

Make sure your machine is up to date with operating system patches. (See Windows Update). Ensure you have a good firewall in place. This is really important, a firewall such as ZoneAlarm will stop things getting in which shouldn't be allowed in, but if somehow your machine becomes infected it will alert you when it attempts to connect to the internet - you can then choose whether to allow or deny the attempt. It's irritating when you have to set up your legitimate programs but that minor irritation is well worth the payoff if a bot gets installed on your computer. Finally a good anti-virus program should prevent attack or in the worst case clean it up.