Most of these stats or reports don't really mean anything.
Most of the so called adware or malware was probably self installed by the user, this applies to almost everything. Most people, Windows users, Mac users, run in admin mode with no UAC. If they just stopped doing that and using the root/admin account for everything you would prevent most malware. The next part is the source of the software, people don't verify sources, they just blindly trust some exe file because a friend told them it's the new thing and go download/install it from some random unknown mirror.
Using trusted sources, peered reviewed repositories, gpg key signature verification/hash verification, this is all standard stuff in power user land, you'll find it most often with Linux users but it could be done on Windows or Mac equally as well.
I'm a Linux guy and I'll tell you that when it comes to security, not privacy (that's different), any OS can be secure, Windows 10/Mac can be just as secure as anything realistically. People need to stop trying to splice hairs and read CNET articles on which OS is most secure for them and just stop being a noob in general. First day of comp sci (that I eventually dropped out of) when you ask why such and such won't run they told me, ID 10 T error is the #1 reason for every one of your failures.
Asus Prime X370-A AMD Ryzen AM4 DDR4
Gigabyte GeForce GTX 950
2x Corsair Valueselect 8GB 288 Pin DDR4 SDRAM DDR4 @ 2133
Corsair Force LS 2.5" 120GB SATA III MLC SSD
Lite-On 24X SATA DVD/RW Optical Drive
Corsair RM550x 550W 80 Plus Gold
Noctua NH-L9A-AM4 Low-Profile
Antec NSK4100 Steel ATX Mid Tower
Mint 18.2 x64
HP 24" LCD/LED 1920x1080
Asus Essence STX II
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