What's a piece of data worth? It's not too hard to find out. Just go to one of the dozens of online marketplaces where stolen credit card numbers, PINs, and Social Security numbers can be purchased--individually or in bundles--starting at just a few dollars. A few dollars is all that's needed to ruin someone's credit rating, drive up their debt, and make them question whether to trust you with their information next time.Anyone in management at TJX Companies would tell you that any price paid for proper security policy and execution on that policy is worth it, as that company faces the consequences of Payment Card Industry Data Security Standard violations and class-action lawsuits from banks and consumers. In just a few months, a number of fraudulent transactions have resulted from an intrusion into TJX's IT systems. InformationWeek will soon publish a story that delves deeply into the seedy underground of the cybercrime economy, describing how stealing information begets identity theft and fraud.

Here's just a little of what we've learned so far.

How stolen bits and bytes of data can be monetized by cybercriminals is an interesting process. It starts with data theft, which can take the form of an intrusion into a company's systems through a network hack, a phishing scam where victims are duped into actually volunteering their personal information, an inside job where a disgruntled employee steals an employer's records, or a smash and grab, where a corporate laptop is stolen from an employee or contractor's car.

From there, the data can be advertised on online marketplaces that let thieves sell stolen data to fraudsters. It's always a good idea to be on the lookout for a bargain, so the fraudsters try to buy their information in bundles. According to security vendor Trend Micro, a credit card number with PIN can fetch about $500 on the open market, while billing data, including account number, address, Social Security number, home address, and birth date, goes for between $80 and $300. Not surprisingly, credit cards with a low balance and high spending limit (such as a platinum or gold card) are the most valuable types of cards.

Thieves and fraudsters do business much the same way you and I would use eBay to buy and sell a cocktail napkin signed by a celebrity. A price is negotiated, and then payment arrangements are made through a peer-to-peer payment system like PayPal or E-gold, which lets people exchange electronic currency backed by the value of gold bullion rather than a particular national currency.

Once the fraudsters take possession of the stolen data, they can use it to make online purchases or even sign up for more credit cards, assuming they've purchased all of the different types of information required to fill out a purchase order or card application. The more industrious fraudsters will program the data into counterfeit credit and debit cards, sometimes using discarded gift cards from the holidays. They can then take these cards to stores and attempt to make purchases by signing a bogus name, as long at the cashier doesn't check the signature (and how many do?).

In the early 1990s, the same person took on multiple roles, which included stealing the information and using the stolen information to commit fraud, Uriel Maimon, an RSA Consumer Solutions researcher, told me the other day. Today, one person writes the malware used to steal information, while another person plants and collects the stolen information, and a third person uses that stolen information to steal money. Another new trend is the tendency for attackers to target high-worth accounts rather than stealing smaller amounts of money from a larger number of accounts, Maimon added.

There's plenty more insight into the cybercriminal economy to come, so keep a lookout for our upcoming story in the pages of InformationWeek and on InformationWeek.com.