Hackers, Crackers & List of Computer Viruses

Hackers & Crackers

1. A cracker (also known as a black hat hacker) is an individual with extensive computer knowledge whose purpose is to breach or bypass internet security or gain access to software without paying royalties. The general view is that, while hackers build things, crackers break things. Cracker is the name given to hackers who break into computers for criminal gain; whereas, hackers can also be internet security experts hired to find vulnerabilities in systems. These hackers are also known as white hat hackers.  Crackers’ motivations can range from profit, a cause they believe in, general maliciousness or just because they like

the challenge. They may steal credit card numbers, leave viruses, destroy files or collect personal information to sell.

2. Crackers can also refer to those who reverse engineer software and modify it for their own amusement.  The most common way crackers gain access to networks or systems is through social engineering, whereby the cracker contacts employees at a company and tricks them into divulging passwords and other information that allows a cracker to gain access.

The difference between hackers and crackers.

A hacker is a person intensely interested in the arcane and recondite workings of any computer operating system. Hackers are most often programmers. As such, hackers obtain advanced knowledge of operating systems and programming languages. They might discover holes within systems and the reasons for such holes. Hackers constantly seek further knowledge, freely share what they have discovered, and never intentionally damage data.

A cracker is one who breaks into or otherwise violates the system integrity of remote machines with malicious intent. Having gained unauthorized access, crackers destroy vital data, deny legitimate users service, or cause problems for their targets. Crackers can easily be identified because their actions are malicious.

Additionally, it should be mentioned that there are two major types of crackers. The first is fortunately few and far between. They are the expert crackers who discover new security holes and often write programs that exploit them. The second type, the script kiddie, only knows how to get these programs and run them. Script kiddies are more numerous, but much easier to stop and detect.

Tools of the Trade

The "tools of the trade" are the means a cracker or hacker might use to penetrate your

network. Some of the tools covered are programs, and some of these tools are

techniques.

Reconnaissance

When most people hear the word reconnaissance, they think of spies and the

espionage world. Although that community does indeed use reconnaissance, so does

the cracker community. What is reconnaissance, and why do crackers use it?

Reconnaissance is the process of gathering information about specific target(s). When

a good burglar decides to rob a house, he will scope out an area to see how often

neighbors, cops, and other traffic passes through. This gives the robber a good idea of

the best time of day to attack. The same basic philosophy holds true for a cracker when

she wants to attack a network or Web site.

When a cracker decides she wants to attack a network, there are many "recon" tools at

her disposal. Let's look at a few of them and see how they work.

Social Engineering

The first and probably the most underrated tool available is social engineering. Social

engineering involves tricking, conning, or manipulating people into providing information

detrimental to a company, organization, or a person. This type of information can be

used to help plan, organize, or execute an attack.

Computer Viruses A computer virus is a computer program that can copy itself and infect a

computer without the permission or knowledge of the owner. One of the first detected virus was the Creeper virus in the early 70’s

List of Computer Viruses

1. My Doom My Doom explored its way to the malware world on 26th January 2004 and sent a shockwave around the world as it scattered exponentially via e-mail with random senders’ addresses and subject lines. My Doom also known as “Novarg” is reported to be the most dangerous virus ever released, breaking the previous record set by the Sobig F worm. My Doom swiftly infected some two million computers and instigated a huge denial of service attack which smashed the cyber world for sometime. 

2. ILOVEYOU Back in 2000, one of the trickiest computer malware ever was detected on May 4 in Philippines. Around 10% of the internet users committed a huge mistake by going on the name of this hazardous worm. The virus played on a radical human emotion of the need to be loved because of which it became a global pandemic in only one night.

3. Sobig F August 2003 turned out to be the miserable month for corporate and domestic computer operators around the world as the sixth and most destructive deviant of Sobig series hit the internet

4. Code Red In the summer 2001, a computer worm most commonly referred to as “Code Red” was unleashed on the network servers on July 13. It was a very sneaky virus which took advantage of a flaw in Microsoft Internet Information Server

5. SQL SlammerSQL Slammer, a standalone malicious program also known as “Sapphire” appeared at the starting of the year 2003 and was the first fileless worm which rapidly infected more than 75000 vulnerable hosts within10 minutes on 25thJanuary.

6. MelissaMelissa was the first mass-mailing macro virus for the new age of e-mailing which became the breaking news across the world on March 26, 1999. 

7. CIHA destructive parasitic virus CIH also known as “Chernobyl” was first emerged in the year 1998 in Taiwan and quickly became one of the most dangerous and destructive viruses to ever hit with a payload that corrupts data. 

8. Storm WormThe dreaded Storm Worm struck the cyber world as a malicious Trojan horse program in late 2006 when users began receiving e-mails with a subject line “230 dead as storm batters Europe.”

9. ConfickerIn 2009, a new computer worm Conficker also known as Downup, Domnadup and Kido crawled its way into as many as fifteen million Microsoft Windows operating systems around the world without human intervention using a patched Windows flaw. 

10. NimdaNimda first surfaced in 2001 and hastily rosed to the top. The name of the virus is derived from the word “Admin” spelled backwards. It just took 22 minutes for this dangerous virus to propagate via four different ways – e-mail, server vulnerabilities, shared folders and file transfer.

 11. Code RedThe first worm that spread without requiring any user interaction at all and thus spread around the world in minutes, Code Red hid from detection and carried out various functions on a cycle.

12. LoveletterThe computer worm that broke millions of hearts, Loveletter is still one of the biggest outbreaks of all time. It spread via email attachment and overwrote many of the crucial files on the PCs it infected. This outbreak was an incredible successful attempt at social engineering.

13. Cyber SabotageComputer viruses have had real world effects for decades, but in 2010 a computer virus may have changed the course of history.

14. ConfickerConficker quickly took millions of computers all over the globe. It exploits both flaws along with Windows and weak passwords along with several advanced techniques.

15. 3D Anti TerroristThis trojanized “game” targets Windows Mobile phones and was spread via freeware sites. Once installed, it starts making calls to expensive numbers leaving you with large charges.