The 6 worst kinds of computer hackers

Hackers cost companies and other large institutions millions every year in damage and lost productivity.

HAK25 hacker types

If the Internet has one enduring constant, it's that somewhere, somehow, somebody is being hacked. Last month cyberassaults on banks, including BB&T (BBT, Fortune 500), Citigroup (C, Fortune 500), and SunTrust (STI, Fortune 500), made headlines. But a recent Ponemon Institute survey reported that the average company is attacked twice a week and loses $8.9 million a year to cybercrime. Security analysts say the first thing businesses must know is just what types of threats are lurking in the shadows. While many hackers use relatively basic tools, such as phishing or malware, they often wield them with different motives. Here are six of the most effective actors.

  @FortuneMagazine - Last updated February 26 2013 06:33 AM ET
Join the Conversation
Market indexes are shown in real time, except for the DJIA, which is delayed by two minutes. All times are ET. Disclaimer LIBOR Warning: Neither BBA Enterprises Limited, nor the BBA LIBOR Contributor Banks, nor Reuters, can be held liable for any irregularity or inaccuracy of BBA LIBOR. Disclaimer. Morningstar: © 2014 Morningstar, Inc. All Rights Reserved. Disclaimer The Dow Jones IndexesSM are proprietary to and distributed by Dow Jones & Company, Inc. and have been licensed for use. All content of the Dow Jones IndexesSM © 2014 is proprietary to Dow Jones & Company, Inc. Chicago Mercantile Association. The market data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved. FactSet Research Systems Inc. 2014. All rights reserved. Most stock quote data provided by BATS.