6 David Smith infected hundreds of thousands of computers through pornographic emails, disrupting communication on a massive scale. These brought down the e-mail systems of many big organizations including that of the Department of Defense.

On March 26, 1999, David Smith released the fast-breeding Melissa Virus through e-mails targeting MS Outlook and Word. A Word .doc attachment that listed login details of pornographic sites accompanied the malicious emails.

The virus would then replicate and spread the email to the first 50 contacts of the victim while also compromising the safety features of MS Word and Outlook.

The hack succeeded in disrupting the most popular means of business communication, e-mails.

Smith was arrested after being tracked down by a cybercrime task force with the help of technology experts from the FBI. On May 1, 2002, he was given a fine of $5,000 and sentenced to federal prison for 20 months. (1, 2)

7 Nicknamed the “Smiling Hacker,” Hamza Bendelladj made it to the FBI’s list of “10 most wanted hackers” for siphoning billions of dollars through the botnet “SpyEYE.” In Robin-Hood-style, he supposedly donated a  chunk of the stolen money to charities.

This Algerian hacker developed the SpyEYE botnet with help from Aleksandr Andreivich, a Russian hacker. He used the virus to break into systems of financial institutions and stole identification pins and account passwords. With the acquired information, he embezzled money from around 200 European and American financial institutions amounting to billions of dollars.

Also known for hacking the Israeli Government’s official website, a smiling Bendelladj was arrested by the Thai police on January 8, 2013, in Bangkok after a three-year hunt by the FBI.

Though there were reports of huge donations to Palestinian charities by the hacker, it remained unverified. He was sent to prison for 15 years followed by three years probation. (1, 2)

8 Cameron Lacroix hacked into Paris Hilton’s phone and broke into the computer servers of a community college to change his grades. Undeterred by his arrest and subsequent release, he went on to hack his employer’s computer system to fund his credit cards.

In 2005, at the age of 17, Cameron broke into Paris Hilton’s cell-phone and posted the celebrity’s contact numbers and revealing photos online. As part of a hacking group, he infiltrated the computer systems of LexisNexis and exposed the data of over 300,000 customers.

The break-in caused $1 million in damage to his victims. He also hacked the Bristol Community College’s servers to change not only his grades but also those of his friends.

In 2005, the teen hacker was sentenced to a juvenile detention facility for 11 months. Upon his release, he was directed not to possess or use any electronic equipment for two years to prevent him from Internet access.

However, in 2018, after his release, he hacked into the computer system of the company he was employed with and transferred money to his credit card by using passwords and usernames of other employees.

This fraud led to the revocation of his release and he was eventually sentenced to prison for 15 months. (1, 2)

9 Albert Gonzalez threw extravagant parties and stayed at luxury hotels by stealing and then reselling details of over 170 million credit and debit cards. During one of his arrests, police recovered $1.6 million in cash dumped in his parents’ backyard.

Gonzalez began his hacking career at the age of 14 when he hacked into NASA. He committed his first fraud with the group ShadowCrew by selling around 1.5 million stolen card numbers on the website Shadowcrew.com. The website also held auctions of identity details, acquired through cybertheft, such as birth certificates, Social Security cards, passports, and others. Though accused of being the mastermind of the trafficking business, he was not indicted.

He was also the leader of the group that hacked TJX companies in  2005 and the Heartland Payment System in 2007, gaining illegal access to card numbers of around 170 million ATM and credit card numbers.

After being arrested and sentenced to 20 years in prison twice in 2010, he claimed to have been working with the United States Secret Service to hunt international cybercriminals. His plea was met with silence from the Secret Service. (source)

10 After getting fired from Omega, Timothy Lloyd sabotaged the company’s software that ran the manufacturing operations. This resulted in the layoff of 80 employees and a loss of $10 million in revenue.

Timothy Lloyd had worked at Omega for 11 years before being fired for not getting along with his coworkers in 1996. He was working as a network administrator at the time and knew the system well.

Three weeks later, Lloyd hacked into Omega’s systems and wrote a six-line code bomb.  On July 31, 1996, the code was activated as soon as an employee logged into the server. The code deleted the software necessary for the manufacturing process which stalled their operations at their Bridgeport factory in New Jersey.

The breach cost the company, whose clientele included the US Navy and NASA, a loss of $10 million in revenue and an additional $2 million in repairs. Also, the huge loss led to 80 employees losing their job. The man behind the sabotage was sentenced to federal prison for 41 months. (1, 2)