Short answers, pulled from the story.
Malware is a portmanteau of "malicious software" and refers to any program intentionally designed to disrupt, destroy, steal data, or gain unauthorized access to computer systems. Researchers classify it into sub-types including viruses, worms, Trojan horses, ransomware, spyware, adware, rootkits, and keyloggers.
The first IBM PC virus documented in the wild was a boot sector virus called (c)Brain, created in 1986 by the Farooq Alvi brothers in Pakistan.
Cybercrime, which includes malware attacks, was predicted to cost the global economy US$6 trillion in 2021 and is increasing at a rate of 15 percent per year.
Locker ransomware locks down a computer system without encrypting its files, while crypto ransomware both locks the system and encrypts its contents, demanding payment, typically in Bitcoin, before restoring access. CryptoLocker and WannaCry are examples of crypto ransomware.
Stuxnet was malware engineered to interfere with specific industrial control systems, widely cited as a politically motivated cyberweapon. It could spread across air-gapped networks via a USB drive without needing to exfiltrate any data.
An estimated 33 percent of malware is not detected by antivirus software. Techniques such as payload encryption, polymorphic code, fileless execution in memory, and Living off the Land methods all help malware evade detection.