How Do Hackers Get Into Computer Systems?

In the computer world, there are good guys who create networks that help us communicate, work with others and get information...and then there are those not-so-good guys and girls who, for a variety of reasons, like to use their computers to worm their way into those networks and cause trouble.

They're called hackers, and they'll routinely do things like:

Steal secrets.
Obtain passwords.
Get credit card information.
Create so much traffic that a website has to shut down.

Hackers are ALWAYS at work, either trying to steal information for their own gain or disrupt business as usual. You hear a lot of about hackers on the news now and then, but just what are they doing?

Here's a bit of background to help you understand what it means when a website or company is "hacked."

Hackers aren't heroes.

For some reason, there are those who think that hackers are "cool" and that their spirit of mischief and sneaking is admirable. But the IT (Internet technology) experts who spend a lot of money building business or government networks would disagree. And, for that matter, so would anyone who has ever had their money or identity stolen by a hacker. There's nothing playful about that.

Most people would agree that there are three types of hackers:

Young kids "having fun." These are adolescents who are essentially vandals on the Internet and are also know as Script Kiddies. They're not looking for more than a few hours of their fun messing with websites or networks.
Recreational "hackers." These are savvy computer users who intrude on networks when they feel they have a valid reason to...in their minds at least. They may have a grudge against a certain website or company and take their dislike out by "hacking" or disrupting the website.
Professionals. When a computer expert gets a taste of hacking and likes the flavor, he or she will continue to use their skill, often for breaking into people's accounts to steal money. They also might like taking down a big network for "fun."

Stealing passwords and getting in the system.

Finding out a password is the usually the first step in cracking a network's security. (That's why there are so many articles telling you to change your passwords often and make them hard to figure out!)

Here are a few key terms that you'll hear in discussions about hackers and what they do:

Back door. A secret pathway a hacker uses to gain entry to a computer system.
Buffer overflow. A method of attack where the hacker delivers malicious commands to a system by overrunning an application buffer.
Denial-of-service attack. An attack designed to cripple the victim's system by preventing it from handling its normal traffic, usually by flooding it with false traffic.
Email worm. A virus-laden script or mini-program sent to an unsuspecting victim through a normal-looking email message.
Root access. The highest level of access (and most desired by serious hackers) to a computer system, which can give them complete control over the system.
Root kit. A set of tools used by an intruder to expand and disguise his control of the system.
Script kiddie. A young or unsophisticated hacker who uses base hacker tools to try to act like a real hacker.
Session hijacking. When a hacker is able to insert malicious data packets right into an actual data transmission over the Internet connection.
Trojan horse. A seemingly helpful program that tricks the computer user into opening it, only to deliver (unnoticed and behind the scenes) an unexpected attack on the user's computer.

Keeping safe.

You can protect yourself simply by creating passwords that are hard to predict, by using different passwords for different accounts, and by changing passwords every so often.

These steps help to prevent you from being an "easy" target.

The Hackers