The world’s most notorious computer viruses have ravaged hardware and software, leaving users gobsmacked in the process. All manner of malware, adware, worms, Trojans and viruses have infiltrated Windows systems over the years. Some of the worst viruses to attack Windows operating systems include the following:
This computer virus is considered one of the worst ever, and the damage it inflicted is estimated at around $10 billion. The severity of the ILOVEYOU virus caused many corporations and governments to take their computers and networks off-line to prevent infection. The creators of this malicious code were Onel de Guzman and Reonel Ramones of the Philippines. They deviously attached a hidden file that posed as a TXT file. Once the user clicked on the file, it automatically sent itself to everyone on the mailing list. Next, it made the computer unbootable by overwriting all of the files in the system. At the time, there were no regulations against malware and both Ramones and Guzman were never charged. The ILOVEYOU virus was delivered via email and then when the recipient opened it, it created multiple copies of itself. Instead of sending usernames/passwords back to the sender, it simply overloaded programs all over the world, and at the highest levels. In a surprising development, the Philippines government has utilized the incident to promote the country’s inexpensive IT talent.
The Melissa Virus was created by David L. Smith in 1999. It was named after an exotic dancer from Florida. This virus began as a Word document posted on an alt.sex USENET group. It purported to have passwords to a list of adult content websites. When people downloaded the word document, the hidden virus would mail itself to 50 people in the recipient’s email address book. David L. Smith was apprehended within seven days of the virus being delivered. According to estimates, the Melissa virus resulted in $80 million worth of damages. Smith was fined $5,000 and served a stint of 20 months of a 10-year sentence. Of particular importance is its effectiveness against clickjacking – which is similar to how the Melissa virus infected computers in the first place.
ZEUS Trojan Horse
Zeus is a Trojan horse that captures personal information such as keystrokes and forms. Windows computers were particularly vulnerable to this virus when it was unleashed in 2009. Tens of thousands of FTP accounts and computers of huge corporations were affected. These included Cisco, Amazon, Oracle and Bank of America. It is reported that upwards of 1 million US computers were affected, and it was part of a vast multinational cybercriminal operation. The masterminds of this virus were located in Eastern Europe. Some 100 people were arrested for their part in the criminal syndicate, and the ringleader of the Zeus Trojan horse purportedly retired in 2010. Multiple instances of fake Zeus virus warnings have been reported by computer users around the world. This is yet another instance of malware and hackers piggybacking off a known virus for their own ends. These forms of browser redirects can be protected against by downloading and installing effective antivirus software.
Other High Profile Worms, Trojans, and Malware for Windows PCs
There are scores of other viruses that have affected Windows computers over the years, including a Trojan horse ransomware known as CryptoLocker, Mydoom (a Windows worm), the Stuxnet Virus (created by the IDF and the American government), Conficker (wreaking damage worth an estimated $9 billion), and the Sasser worm (causing $18 billion worth of damage). The golden rule is never to open attachments from suspicious senders, or unsafe sites. The best defense is a strong offense with effective antivirus software.