There is no conclusive answer to this question as the most typical type of malware varies depending upon which area of the world you lie in, and likewise alters in time. However, a few of the most common kinds of malware include infections, worms, Trojan horses, and adware.
Viruses are one of the oldest and most common types of malware. Adware is a type of malware that displays advertising on a computer, typically in a pop-up window.
Malware is continuously evolving, and brand-new types are constantly being produced. https://creaturesincrisis.org/?p=1363 The types discussed above are some of the most typical that you might come across. Source