Once a computer is infected, it becomes a bot or zombie, waiting to do the bidding of its bot operator. These remote controlled computers or bots would then be used to launch a DOS attack (Denial of service), send spam, spread spyware, and assist in the theft of personal information such as credit card numbers, login ids and passwords.
Thousands of computers are enrolled every day into a botnet. It is estimated that a fourth of all computers online are a part of various botnets.
A few years ago only a technically adept person could create and deploy botnets. Not so today. A cyber criminal without any technical knowledge, can now buy a botnet kit online for a few dollars. These applications offer point and click functionality. With the click of the mouse a criminal can get information on the geographic location of his newly enrolled bot, the windows patches installed, the browsers used and even encrypted communication between bot operator and the zombie computer.
These steps illustrate how a computer is enrolled as a zombie and then used to send spam, spyware, and conduct other nefarious activities:-
- The Bot operator sends a virus or worm usually through email to an unsuspecting user
- The user opens the mail and clicks on a link or opens an attachment; the virus activates its payload which in this case is the bot
- The bot immediately contacts a control server set up by the Bot operator and announces the success of its mission
- The owner of the bot then monetizes his army of bots or zombies by selling access to the botnet to spammers. The spammers then send thousands of emails to the control server which in turns directs the infected PC to send spam.
These tips will help defend your computer from being enrolled into a zombie army.
- Try not to visit undesirable sites such as those involving sex, nudity, criminal skills, warez, pirated software, and illicit drugs. If you share your computer with other people you can create a firewall rule to prevent access to such sites. Check with your ISP if they offer a content filtering service, if they do sign up for it.
- Since must systems are infected by means of a Trojan, virus or worm it is wise to have a good anti virus program installed with the latest virus definition files
- Emails are favorite medium with cyber crooks for enrolling systems on to their botnets. Be suspicious of every email you receive even if it is from a known person. It is a simple matter for these criminals to spoof an email. Never click on a link instead type the link on your browser address bar. Open attachments only after you have downloaded and scanned it for threats.
- Consider changing your browser to Firefox. Most exploits center on the security flaws of Internet Explorer. You can reduce the odds of your system being turned into a zombie by simply replacing your browser.
If you suspect your system is infected with a bot you can use this excellent free tool RUbotted from Trend Secure (http://www.trendsecure.com) to detect the presence of a bot. Because Bots are typically worms you might want to remove it with an anti-virus tool. Make sure to update your anti-virus with the latest definition files before you attempt to clean the infection.
