: Widely considered the costliest outbreak in history, causing an estimated $38 billion in damages (over $52 billion adjusted for inflation).
: The first major mass-mailing virus of the modern era, which forced many large companies like Microsoft to shut down their email systems entirely. 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. : Widely considered the costliest outbreak in history,
: Notorious for spoofing sender addresses, making it appear as though the virus came from a trusted contact. : Notorious for spoofing sender addresses, making it
: A fast-spreading worm that caused roughly $30 billion in damage by overloading corporate servers with millions of emails.
While "AZMATH" appears to be a specific niche or community-driven list, the consensus across major tech resources like HP Tech Takes and Britannica highlights a consistent group of notorious digital threats. These viruses and worms are ranked by their financial impact, speed of infection, and sheer destructive capability. The Top 10 Most Notorious PC Viruses
: A sophisticated worm that created a massive botnet of millions of infected Windows computers, targeting government and business servers.