Zombies and botnets: help keep your computer under your control

Circle of SpamFrom the Microsoft Security Website:

Online criminals can use a virus to take control of large numbers of computers at a time, and turn them into “zombies” that can work together as a powerful “botnet” to perform malicious tasks.

Botnets, which can include as many as 100,000 individual “zombie” computers, can distribute spam e-mail, spread viruses, and attack other computers and servers, and commit other kinds of crime and fraud.

Zombies have been used extensively to send e-mail spam; between 50% and 80% of all spam worldwide is now sent by zombie computers. This allows spammers to avoid detection and presumably reduces their bandwidth costs, since the owners of zombies pay for their own bandwidth.

Botnets are highly valued by online criminals, and have become a serious problem on the Internet. Two major viruses (netsky and bagel) were created to compete for control of a large botnet, and botnet-controlled zombie computers have even been found in places such as the United States Department of Defense.

How to tell if your computer has been infected

The virus that is used to make your computer into a zombie might cause your computer to slow down, display mysterious messages, or work in an unexpected manner.

These viruses usually do not disable your computer, because zombie computers must be plugged in and connected to the Internet in order for the botnet to work.

What to do if your computer is infected

If your computer shows symptoms of virus infection, first make sure that the software on your computer is up to date. Then, run current antivirus and antispyware software to scan your computer and remove unwanted software.

5 ways to help keep your computer from becoming a zombie

Because prevention is always better than cure.

  1. Never open attachments in e-mail, instant messages, or mobile messages unless you know exactly what the attachment is, even if it’s from someone that you know. Attachments can contain e-mail viruses.
  2. Use an Internet firewall.
    Note: Windows XP with Service Pack 2 (SP2) has a firewall already built-in and active.
  3. Stay up to date. Visit Microsoft Update and turn on Automatic Updates.
    Note: If you’ve installed Microsoft Office 2003 or Microsoft Office XP, Automatic Updates will also update your Office programs. If you have an earlier version of Office, use Office Update.
  4. Subscribe to industry standard antivirus software and antispyware software, and keep them current.
  5. Use licensed software products. Botnets are often comprised mostly of computers that run illegally copied versions of operating system and productivity software. Unlicensed software can be more susceptible to viruses, and can even come with viruses already installed without your knowledge.

If you feel your PC security may be compromised or would like more information on preventative measures please contact us.