"Pharming," is a method hackers use in which they can redirect computer users' browsers and direct them to spoofed banking or e-commerce sites. In other words, you can be directed to a site that looks just like your bank site. At that point, when you enter your personal information such as account number & password, it will be in the hands of the hacker.
How can this be prevented? As with most information security issues, security awareness will allow you to recognize these social engineering threats.