When many computers have been hacked to turn them into zombies computers, we call such a group a Botnet. Those computers are being used by cyber criminals to send spam emails and/or to attack websites. If your computer is going to get infected by some "bots", chances are it will become part of a Botnet and your PC will then be another zombie one of that group. Your computer will be controlled at distance by some hackers using a control server and bot-herder command. Those Botnets can hurt networks, websites, personal computers, and more. They are one of the most dangerous problems over the Internet. Problems like viruses, malware, spyware can also be distributed via those Botnets, besides all the spam emails. Another popular attacks on servers being done by those Botnets are the Denial of Service (DoS) and the Distributed Denial of Service (DDos). It is an attempt by those compromised computers to overload a website with many requests at once, thus trying to shut it down because of the excessive amount that the server cannot simply handle. Here Computer Repair Service you can find a great online service ready to repair any problems your PC may have.
The usual way you can get infected by a Botnet is via viruses and trojans carrying such threat. So a common way to get those trojans and viruses is via all those spam emails you are receiving. Also if you do visit a compromised website where you download some fake codecs thinking it is a good video or audio one. Once it has infected your PC, the malicious program will connect itself to its bot-herder server and be ready to do more damage. Like preparing itself to send lots of spam emails, or to start attacking some websites or to spread itself to others PC around the world. Most of a botnet’s activity occurs without the user noticing any major difference in their computer; therefore it is important that users have a clear understanding of how to recognize a botnet infection. This site Virus Removal has good infos about spyware removal.
The first sign that your computer is infected with a botnet is the inevitable slowing down of your computer. Your internet connection will also slow down drastically due to the many connections being maintained by the botnet program. You might notice 2 more things: you have less hard disk space than before and your browser is not working as usually. In other words, your browser will close unexpectedly, its homepage will be irreversibly changed, and your desktop will be inexplicably changed.