Malware can have negative effects on computers. It is software designed to harm systems or gain unauthorized access. Examples include viruses, spyware, and botnets. A brief history of malware outlines some of the earliest known viruses from the 1970s to the present. Today, malware constantly evolves to exploit new computer capabilities. Victims experience issues like decreased performance and unexpected programs/ads. Users can take precautions like antivirus software, but experts worry future malware may increasingly endanger systems since attacks evolve while defenses must catch up.