Phishing schemes are spam e-mails sent to thousands and sometimes millions of recipients, often with the intention of getting the user to click and open an infected file.

They can be very rudimentary or incredibly sophisticated, depending on the skill of the attacker.

For instance, some phishing schemes send victims to spoofed banking websites that look just like the real thing. They usually tell recipients via e-mail that they need to log on to view some kind of important correspondence or keep their accounts active. But when victims log into the fake site, their credentials are given to the attackers.

Last updated July 29 2011: 5:11 AM ET
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The cyber Mafia has already hacked you

Large, organized crime syndicates have been launching sophisticated attacks for decades.