: A sophisticated worm that created a massive botnet of millions of infected Windows computers, targeting government and business servers.
: An advanced Trojan horse used to steal banking information, reportedly affecting 88% of Fortune 500 companies. The Top 10 Worst PC Viruses of All Time – AZMATH
: A massive ransomware attack that encrypted files and demanded Bitcoin payments, famously crippling the UK's National Health Service. : A sophisticated worm that created a massive
: The first major mass-mailing virus of the modern era, which forced many large companies like Microsoft to shut down their email systems entirely. disguised as a love letter that
: One of the most famous social engineering attacks, disguised as a love letter that, once opened, sent itself to everyone in the victim's Outlook address book.