Computer viruses have come a long way from floppy-disk pranks to today's AI-assisted cybercrime. The 2020s have turned malware into a professional industry, complete with ransomware cartels, AI-driven phishing and even research projects masquerading as real-world threats. As of September 2025, the fight is no longer about who writes the nastiest script; it's about who trains the smartest algorithm, and the results are both fascinating and frightening.