What is the purpose of rootkit?

Hi,

A rootkit is some kind of a Trojan that gives a hacker/cracker the access to your computer without you knowing it. It can come in a zip file or while Surfing online. Once the rootkit is installed on your computer, it sends a message to the cracker that he/she can now access the host machine. Then the cracker can use that machine as if it was his own.

So why do crackers do it? Well, for starters the challenge is there. Being able to see someone else's computer/ files gives them some weird satisfaction. But more importantly they do it to acquire personal information about the host. (addresses, phone numbers, birthdays, email addresses, bank information etc.) Most of the time they sell this info to other parties that are willing to pay a lot of bucks for it. (although now we give it for free via websites like facebook, if you know what i mean:) ) Another reason is that since they are using someone else's computer, it gives them the freedom to do things that otherwise they would get into trouble with their own machines. (visiting child-porn, hacking websites or chatting/ cybersex with minors). I know people that got into trouble like that.

A rootkit is hard to detect by using conventional antivirus software. google "anti rootkit software" and you'll run into a bunch of software out there. Run this software regularly on your machine and you should be fine.