Global market share held by Windows anti-malware vendors 2022-2023, by month

Symantec Corporation held 77 percent of the Windows anti-malware application market as of May 2023, more than any other vendor. It was followed by Norton 360, with a market share of 15 percent. In 2019, Symantec sold its Enterprise Security software division to Broadcom and renamed the remaining business to NortonLifeLock.

Beware the Trojan horse

Malware is software designed to maliciously interfere with the regular operation of computers or mobiles. This includes the destruction or gathering of data, presenting unwanted advertising, or rendering a device vulnerable to external control. There were 5.5 billion malware attacks in 2022 alone, down from 10.5 billion in 2018.
Trojan horses are the most common methods of infection, in which a user is tricked into downloading malware, disguised as a legitimate product.

Malware targeting Windows

While all users of devices connected to the internet are vulnerable to malware infections, certain systems are more vulnerable. Malware developers target windows-based systems more than any other, with 83.45 percent of newly detected malware programs in the first quarter of 2020 targeting machines running Windows. This is not to say that users of MacOS are immune, with malware such as Flashback, Macontrol, and Shlayer all designed to infect systems running MacOS.