Famous Computer Viruses

Famous Computer Viruses

• ILOVEYOU (2000)

• Type: Worm

• Effect: Spread via email with the subject "ILOVEYOU," infecting millions of computers worldwide. It overwrote files and sent copies of itself to all contacts in the user's address book.

• Melissa (1999)

• Type: Macro Virus

• Effect: Spread through Microsoft Word documents attached to emails. It caused infected computers to send the virus to the first 50 contacts in the user's email list, leading to widespread disruption.

• Mydoom (2004)

• Type: Worm

• Effect: Spread via email, causing significant slowdowns in internet performance. It also opened a backdoor to infected computers, allowing for unauthorized remote access.

• Conficker (2008)

• Type: Worm

• Effect: Targeted Microsoft Windows systems, exploiting vulnerabilities to create a botnet. It infected millions of computers globally and disrupted operations by blocking security updates.

• Sasser (2004)

• Type: Worm

• Effect: Exploited a Windows vulnerability to spread without needing user interaction, causing systems to crash and reboot repeatedly.

• Stuxnet (2010)

• Type: Worm

• Effect: Designed to target industrial systems, specifically Iran’s nuclear facilities. It sabotaged centrifuges used in uranium enrichment.

• CryptoLocker (2013)

• Type: Ransomware

• Effect: Encrypted user files and demanded a ransom in Bitcoin to restore access. It affected thousands of systems, often leading to permanent data loss if the ransom wasn't paid.

• Zeus (2007)

• Type: Trojan

• Effect: Targeted banking information, capturing login credentials and financial data through keylogging and form-grabbing techniques.

• WannaCry (2017)

• Type: Ransomware

• Effect: Spread rapidly across Windows systems, encrypting files and demanding ransom payments. It exploited a vulnerability in Windows' SMB protocol and affected healthcare, government, and business sectors globally.

• Code Red (2001)

• Type: Worm

• Effect: Attacked Windows web servers, defacing websites and creating a backdoor for remote control. It caused significant disruption, particularly to government websites.

• Sobig (2003)

• Type: Worm/Trojan

• Effect: Spread via email, designed to create a large-scale spam network by turning infected computers into proxy servers for spammers.

• Storm Worm (2007)

• Type: Worm

• Effect: Spread through email attachments, turning infected computers into botnets that were used for spamming and DDoS attacks.

• CIH/Chernobyl (1998)

• Type: File Infector Virus

• Effect: One of the most destructive viruses, it overwrote critical system files and even damaged hardware by corrupting the BIOS.

• SQL Slammer (2003)

• Type: Worm

• Effect: Exploited a vulnerability in Microsoft SQL Server, causing widespread internet slowdowns and affecting ATMs, airlines, and other services.

• Anna Kournikova (2001)

• Type: Worm

• Effect: Spread via email disguised as a photo of the tennis player Anna Kournikova, but it was a worm that replicated itself through users' email contacts.

Types of Computer Viruses

• Worms: Spread across systems without needing a host file (e.g., Sasser, Mydoom).

• Trojans: Disguised as legitimate software but carry malicious payloads (e.g., Zeus).

• Ransomware: Encrypts files and demands payment to unlock them (e.g., WannaCry, CryptoLocker).

• File Infector Virus: Infects executable files and can spread when those files are opened (e.g., CIH).

• Boot Sector Virus: Infects the master boot record and spreads when the system is booted from the infected drive.

• Macro Virus: Targets software macros, often in programs like Microsoft Word or Excel (e.g., Melissa).

• Polymorphic Virus: Changes its code slightly each time it spreads to avoid detection.