Nowadays, there are far more threats out there than plain viruses. You have probably come across the term spyware as well, however, authors of malicious codes and dangerous websites are very innovative, and new kinds of threats emerge quite often, the vast majority of which are on the Internet. Here are some of the most common:

• Exploit is a malicious code that takes advantage of a flaw or vulnerability in an operating system, Internet browser, or other essential program.
• Social engineering is a common term for various techniques used to trick people into giving away their personal information (passwords, bank account details, credit card numbers etc.). A typical example of social engineering is phishing – an attempt to acquire sensitive personal data by shamming a trustworthy and well*known organization. Usually, the potential victims are contacted by a bulk e-mail asking them to e.g. update their bank account details. In order to do that, they are invited to follow the link provided which then leads to a fake website of the bank.
• Scam can be also considered a kind of social engineering; it includes false job offers, or ones that will abuse the workers for illegal activities, summons to withdraw a large sum of money, fraudulent lotteries and the like.
• Hoax is a bulk e*mail containing dangerous, alarming or just bothering and useless information. Many of the above threats use hoax e-mail messages to spread.

Finally, malicious websites are ones that deliberately install malicious software on your computer, and hacked sites do just the same, only these are legitimate websites that have been compromised into infecting visitors. Read more.