: Notorious for spoofing sender addresses, making it appear as though the virus came from a trusted contact.
: A sophisticated worm that created a massive botnet of millions of infected Windows computers, targeting government and business servers. The Top 10 Worst PC Viruses of All Time – AZMATH
: 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. : Notorious for spoofing sender addresses, making it
: An advanced Trojan horse used to steal banking information, reportedly affecting 88% of Fortune 500 companies. : An advanced Trojan horse used to steal
: The first major mass-mailing virus of the modern era, which forced many large companies like Microsoft to shut down their email systems entirely.
: A worm that exploited a vulnerability in Microsoft IIS web servers to launch DDoS attacks, including one targeting the White House website.
: A massive ransomware attack that encrypted files and demanded Bitcoin payments, famously crippling the UK's National Health Service.