Summary
Highlights
In May 2017, WannaCry (also known as WanaCrypt) caused a destructive global cyberattack. It encrypted computer files, demanding Bitcoin payment, and exploited a vulnerability in Windows systems to spread automatically across networks, affecting hospitals, schools, and businesses. A security researcher eventually discovered a kill switch, but not before hundreds of thousands of computers in over 150 countries were infected.
In the early 2000s, the 'You Are An Idiot' malware targeted user screens, opening endless pop-up windows flashing a mocking message. This consumed system resources, making computers unresponsive and often requiring forced reboots. Some variants reactivated on startup, trapping users in a cycle of crashes, making it highly disruptive despite not stealing data.
The 'I Love You' virus emerged in May 2000, disguised as a harmless text file attachment in an email with the subject 'I love you'. Once opened, it overwrote files and automatically sent itself to every contact in the user's address book. Millions of computers were affected, forcing organizations to shut down email systems, as security measures were unprepared for email-distributed malware.
MyDoom, appearing in 2004, became one of the fastest-spreading computer worms. It spread automatically via email and network connections, scanning infected systems for email addresses and sending itself out with misleading subject lines. It consumed system resources, slowed computers, and launched large-scale DDoS attacks, causing an estimated $38 billion in damages and opening backdoors for remote access.
BonziBuddy, an application from the early 2000s, appeared as a friendly desktop companion but was far from innocent. It collected personal information, tracked browsing habits, displayed intrusive ads, slowed computers, and installed unwanted programs. Its persistence and aggressive data collection led to it being flagged as malicious by antivirus programs, and its popularity quickly faded.
Petya ransomware, identified in 2017, targeted the master boot record rather than individual files, taking control of the entire system. After a fake disk check and a flashing skull, it revealed that files were encrypted, demanding Bitcoin for access. Spreading through email attachments, infected documents, and network vulnerabilities, it locked entire networks, making recovery difficult without proper backups.
Memz, first appearing in 2016, was designed to demonstrate extreme system control rather than steal data or money. Users downloaded and executed it despite clear warnings of serious system damage. Once activated, it triggered a cascade of errors, including random pop-ups, moving windows, inverted colors, and disrupted system sounds. It deliberately stacked these effects, making the system difficult to control, and ultimately overwrote the master boot record, rendering the computer unusable.