By Isaac Palmer
Payment card fraud, arguably one of the most straightforward approaches to financially motivated crime, persists in the face of ongoing anti-fraud efforts from regulators, financial institutions, and retailers. Carding, as it’s often referred to, is the result of coordinated activities between and within communities across the global cybercrime underground, with activities spread out across across deep and dark-web (DDW) forums and sites, encrypted chat services, and open-web social media sites, where threat actors have been known to share tutorial videos and discuss methods.
Since carding activity directly impacts consumers whose money is stolen or whose data is compromised, it can have significant reputational repercussions for organizations that fail to protect sensitive card information. Moreover, as a threat to the financial security of citizens, combating payment card fraud is often a high-priority action item for law-enforcement. As such, some illicit communities have instituted policies for banning users who discuss carding out of fear that such activity could attract the scrutiny of various law enforcement agencies worldwide, including the U.S. Secret Service, which is in charge of addressing financial fraud crimes targeting citizens and financial institutions.
Among threat actors, carding is widely perceived as easy money, a sentiment which Flashpoint analysts have observed across manuals, tutorials, carding websites, and other illicit media. This is partly due to the widespread availability of resources for carrying out carding activity on illicit marketplaces. Some of the tools and resources used by criminals include: card skimmers and shimmers for stealing card data at point-of-sale (POS) terminals, dumps containing compromised card information along with PINs, and services for producing cloned physical cards using stolen data. Criminals can also produce their own cloned cards by purchasing cloning software and card-writing equipment from online vendors.
In terms of intelligence, teams tasked with combating payment card fraud have two basic requirements: (a) to understand evolving tactics, techniques, and procedures (TTPs) and dynamics shaping underground activity related to carding, and (b) ongoing visibility into whether any of their organization’s data has been compromised.
How Vendors Get Victims’ Data
Compromised card data is the raw material that fuels any carding operation, and criminals have many ways of obtaining such data. A dump often includes everything needed for recreating the card physically, or linking the card account digitally with applications such as mobile wallets and shopping applications.
Skimmers and Shimmers
Card skimmers—physical devices that fit over a machine’s card reader and are used to clone magnetic stripe (magstripe) data—have long been among the most common means of obtaining victims’ card data. In the U.S., gas pumps remain a target for carders because the mandate to enforce EMV-enabled transactions on gas pumps has yet to take effect. Prices for skimmers can range from a few hundred dollars to around $2,000 USD.
With the widespread implementation of EMV chips, skimmers are gradually being supplanted by shimmers, smaller devices that are placed inside the ATM to intercept and record communications between the chip card and chip reader. Shimmers may be bundled in kits that also include a user manual, software for converting encrypted card data, and other complementary goods. As with most illicit goods and services, prices of ATM shimmer kits can vary widely, but one typical kit discovered by Flashpoint analysts was advertised at a price of $1,600 USD.
In addition to manuals and resources bundled alongside shimmers, Flashpoint analysts have also discovered online threat-actor tutorials explaining shimmer best practices for successfully installing the devices and not getting caught. Skimmers and shimmers are rarely noticed by users once installed, and many devices allow criminals to discreetly extract stolen card data via Bluetooth or via cellular GSM networks, reducing the likelihood of being caught.
Shimmers are often used more frequently than skimmers in regulatory environments where EMV-chip readers have become ubiquitous. But there is a critical limitation: EMV-chip cards feature additional security in the form of a component known as an integrated circuit card verification value (iCVV). An iCVV is needed in order to copy a card’s EMV chip data. As such, the only way to commit successful fraud using EMV-chip data harvested using a shimmer is if a bank fails to check the iCVV when authorizing a transaction.
This is good news for banks performing these checks, but fraudsters gravitate toward victims of opportunity. Banks that fail to implement thorough iCVV checks are magnets for this type of fraud.
Hacking eCommerce Sites
Skimmers and shimmers aren’t the only way for fraudsters to gain access to victims’ card data. One popular alternative is to hack eCommerce sites and other websites containing customer purchase information, or in some cases, to purchase access to compromised eCommerce sites from other adversaries. Once a site has been compromised, attackers attempt to access its customer database and other sensitive information.
One of the most pervasive social engineering tactics among threat actors, phishing, is also a common means of stealing card data. Under this method, attacks typically contact targets via email, or in some cases, SMS messages, urging them to open a link to a malicious website made to resemble the website of a legitimate bank in a ploy to trick victims into giving up their card data and credentials.
Many types of malicious software can be used to support payment card fraud. Banking Trojans and keyloggers, for instance, can be used to collect card data. As another example, point-of-sale malware infects physical retail payment terminals in order to intercept and steal card data before it is encrypted and sent to the payment processor.
To learn more about how Flashpoint helps organizations combat carding activity and other types of fraud, request a demo.
Senior Analyst II
Isaac Palmer is a Senior Analyst II on Flashpoint’s Hunt Team who has more than 20 years of experience in computer security. He has advised multiple U.S. government agencies in various capacities and has been featured in major online media outlets around the world including Infosecurity Magazine, SC Magazine, and SecurityWeek, among many others. Isaac was a noted contributor to the DGA Archive project presented in Paris, France during BotConf2015.