Malware: Ransomware
Malware is any software intentionally designed to cause damage to a computer, server, client, or computer network. Malware does the damage after it is implanted or introduced in some way into a target's computer - usually through an email and can take the form of executable code, scripts, active content, and etc
Social Engineering
Social engineering, in the context of information security, refers to psychological manipulation of people into performing actions or divulging confidential information.
Criminals use social engineering tactics because it is usually easier to exploit your natural inclination to trust than it is to discover ways to hack your software. For example, it is much easier to fool someone into giving you their password than it is for you to try hacking their password (unless the password is really weak).