How does a Hacker hack?

I do not know and wouldn’t presume to tell you if I did. But I think the first step has something to do with selling your soul to the debil.

I would like to know too, and also what is the purpose of creating viruses to turn loose on the web? What is the motivation? Do they get money somehow or is it the joy of knowing they have ruined 1000’s of computers?

Often the easiest way is social engineering. People are stupid and trusting and if you’re believable theyll tell you theyre user name and password. This was basically how Anonymous hacked HBGarys (a DoD trusted security firm no less) email accounts.

Social engineering isn’t considered true hacking. There are people who are considered ‘crackers’ too, but they use a already known username, and a program that ‘guesses’ passwords until it is successful.

Honestly, hacking is harder to define since most ‘hacking’ is actually considered ‘cracking’ or social engineering. I’m guessing that hackers will get into servers by using backdoors and security holes to gain access to information, therefore bypassing any password protection. I would assume they can do this from looking at the code and finding these holes, or by programming malware that will create the hole for them, but I don’t actually know how they do it.

A hacker uses knowledge of the operating system (UNIX, Windows) and its software (HTTPD, etc.) to find “holes” not patched by the software developer or system administrator. When a system is not fully stable for a period of time, vulnerabilities can be found and exploited by logging into the server using a guest or anonymous account and eventually working toward administrator or root access. The computer is then considered by the hacker to be hacked.

@amujinx semantics semantics. Originally hacking was what we’d call modding today. A hacker would literally hack a system computer into parts.

A hacker is anyone who invents and implements a creative and elegant solution to any problem.

If you don’t believe me, look it up. (source is the Jargon File, also known as the Hacker’s Dictionary)

Your mechanic could be a hacker (my VW mechanic was). Many artists are hackers, and so are lots of other tradespeople (drycleaners, bakers, and carpenters are among the examples I’ve known personally).

It’s true that there are hackers among those who gain unauthorized access to computers. They are in the minority- probably fewer than 1%. Unfortunately there is money to be made in breaking into computer systems and hackers are not necessarily saints (forgive me, Saint Ignucius ) and are sometimes sadly prone to selling their skills to the highest bidder. Often these skills are coded into easy-to-use scripts. These scripts are used by cretins that we call “script kiddies” to break into your computer for financial gain. These people are not hackers. Sometimes they are third-world sweatshop workers forced to run the same pathetic script over and over and over again for hours in hopes of finding a machine that can be exploited for information or taken over for use in a botnet, et cetera. Pity them, if you can.
But don’t pity the pimple-faced high-school schmucks who do this stuff for free. They are fools, and their cupidity and egotism overshadows their actual skill. Good sysadmins find and foil the attempts of script kiddies many times a day… by using scripts of their own.

@koanhead great answer