Some software monetize themselves with partnerships with other companies, and bundling their installers with optional software offers. Starting with UCheck 3.10, PUP Protection is available (BETA) and prevents optional offers to install on the system when running a setup
After a company is victim of a Ransomware, they are asked a ransom to recover the files and avoid them to be leaked online. This is why we have developed DLP, for Data Leak Prevention, in our RogueKiller Anti-malware product.
Computers worms are designed to leverage vulnerabilities that allow them to gain control over a device then scan the network for other vulnerable devices and so one
Trojan horses usually use social engineering, like a pirated software or a fake Office document send by mail, to gain control over a computer. Once installed, they usually hide themselves from the system and make it impossible for the user to remove.