The underground markets always have a steady supply of card numbers on sale and their locations are always moving as they try to elude law enforcement, says Daniel Ingevaldson, chief technology officer at Easy Solutions Inc., a firm that sells anti-fraud products and tracks the activity of the online black markets. A big jump in inventory usually indicates there's been a breach of a major retailer. That's what Ingevaldson's firm saw in the cases of both Target and Neiman Marcus, which also recently reported a breach.
While many of these online bazaars and forums are based in Russia and Eastern Europe, much of the chatter is in English and appears to have been written by Americans, Ingevaldson says.
The types of criminals who buy the card numbers run the gamut, ranging from purely online white-collar crooks to street gangs.
"In reality, card numbers can be bought by anybody with access to the forums and a few Bitcoins in their pocket," Ingevaldson says.
Wisniewski says the people who buy card numbers online and produce the fake cards aren't the ones who try to use them. Using the cards is the riskiest part of the fraud scheme, so the task is usually farmed out to others who are often recruited through spam emails. The recruiters then send them fraudulent debit and credit cards and instruct them to buy large quantities of expensive merchandise or gift cards in exchange for a small percentage of their value.
Card users, once caught, often only have a handler's email address to share with police, making it nearly impossible to find the recruiters, Wisniewski says.
Both analysts say Russia and former Soviet countries are a hotbed for hackers behind these kinds of schemes. The region has a large population of highly educated computer science professionals and law enforcement is extremely lax when it comes to fraud that occurs overseas and not in the hackers' home country.
Wisniewski and Ingevaldson also believe the original authors of the malicious software used in the Target breach are likely based in Russia or Eastern Europe, as some reports on the breach have suggested. But it's unlikely the original programmers do any hacking themselves. They can make a nice living simply selling the code to those who do.
"Keep in mind, it isn't illegal to write these kind of codes, just to use them," Wisniewski says. "And selling them is a lot less risky than taking cards into an Apple store."
