The srizbi botnet is a computer program that was created by some bad people to infect a whole bunch of other computers. This allows the bad people to control all those computers from one central location.
Imagine that your computer is like a toy car that you can control with a remote. Now imagine that someone way far away can take control of that remote whenever they want and use it to drive your car around. They could make it go fast, slow, or even crash it into stuff. That's basically what a botnet does to a computer.
The srizbi botnet was one of the biggest and most powerful botnets ever created. It infected more than 450,000 computers all around the world! That's like infecting every single person in a really big city.
Once a computer was infected with srizbi, it could be used to do all sorts of bad things. The bad people behind the botnet could send out spam emails, steal personal information, and even attack other websites.
Thankfully, with the help of some smart computer experts, the srizbi botnet was eventually taken down. But it serves as a reminder that we always need to be careful when using our computers and make sure we're not clicking on things we shouldn't be.