A detailed explanation of the "barcoding" technique for transmitting card data on the dark web

[Student]

The term "barcoding" in the darknet context doesn't refer to traditional barcodes (such as UPC or QR codes), but is a metaphor or mistranslation related to the encoding of magnetic stripe data on credit or debit cards. In English, the term "stripe encoding" or simply "dumps" (raw data from the magnetic stripe) is more commonly used. This data is stolen using various methods and transferred on the darknet for sale or use in fraudulent schemes, such as card cloning or unauthorized transactions. Below is a detailed analysis of the process, technologies, risks, and security measures for educational purposes.

1. What is a magnetic stripe and how does it work?​

The magnetic stripe on the back of a credit or debit card is a thin layer of magnetic material (usually iron oxide) that stores data in the form of magnetic domains. These domains are regions of specific polarity (positive or negative) that encode binary data (0 and 1). When the card is swiped through a reader, the magnetic transitions are converted into electrical signals, which are decoded into text data.

Magnetic stripe structure​

The magnetic stripe is divided into three tracks (Track 1, Track 2, Track 3), each containing a specific type of information. Coding standards are defined by international standards such as ISO/IEC 7813 (for financial cards) and AAMVA (for driver's licenses in the US). Here are the details:

• Track 1:
  • Format: Alphanumeric, up to 79 characters (7 bits per character, including check bit).
  • Contents:
    • Start marker: %.
    • Format code: B (for bank cards).
    • Card number (PAN, Primary Account Number): 13–19 digits.
    • Separator: ^.
    • Cardholder's name: up to 26 characters (e.g. LASTNAME/FIRSTNAME).
    • Expiry Date: YYMM (year and month, 4 digits).
    • Service Code: 3 digits (indicates where and how the card can be used, e.g. 101 for international transactions without a PIN).
    • Discretionary data: CVV1, PIN Verification Value (PVV) or other bank data.
    • End marker: ?.
  • Example:
    

    %B1234567890123456^DOE/JOHN^2505101xxxxxx?

    Here 1234567890123456 is the card number, DOE/JOHN is the name, 2505 is the expiration date (May 2025), 101 is the service code.
• Track 2:
  • Format: Numeric only, up to 40 characters (5 bits per character).
  • Contents:
    • Start marker: ;.
    • Card number (PAN): 13–19 digits.
    • Separator: =.
    • Expiration date: YYMM.
    • Service code: 3 digits.
    • Discretionary data: CVV1 or other codes.
    • End marker: ?.
  • Example:
    

    ;1234567890123456=2505101xxxx?

    Track 2 is the most important for payments, as it contains the minimum information required for transactions.
• Track 3:
  • Used rarely, mainly for additional data (e.g. PIN or loyalty program).
  • Format: up to 107 characters, structure varies.
  • It is almost never used in financial cards.

Data encoding​

Magnetic stripe data is encoded using the F2F (Frequency/Flux Reversal to Binary) method , also known as Aiken Biphase or Manchester encoding. It works like this:

• 0 is encoded by one magnetic transition (polarity change) in a fixed time interval.
• 1 is encoded by two transitions (for example, from positive to negative and back).
• The reader converts these transitions into bits and then into characters (usually ASCII).

Example:

• The sequence of magnetic transitions +-+--+ can be decoded as 1010.
• Once decoded, the bits are converted into characters, such as 1234 for the card number.

Encryption (such as Triple DES or AES) is sometimes used to protect data, but in most cases, the data on the magnetic stripe is not encrypted, making it vulnerable to theft.

2. How is data stolen?​

Stealing magnetic stripe data is the first step in the barcoding chain. Common methods include:

2.1. Physical theft​

• Skimmers:
  • These are devices installed on ATMs and POS terminals in stores or gas stations. The skimmer looks like a legitimate part of the device, but it reads the data stripe when the card is swiped.
  • Modern skimmers (2024–2025) are often equipped with Bluetooth or GSM modules for wireless data transmission.
  • Example: In 2024, more than 10,000 skimmers were detected at gas stations in the US, according to FICO.
• Shimmers:
  • Enhanced chip card skimmers (EMVs) that read data from the chip, although this is more difficult because the chips use dynamic cryptograms.
• Physical access: Fraudsters operating in stores can use portable readers to copy the stripe.

2.2. Digital Theft​

• Web skimming:
  • Malicious JavaScript code is injected into e-commerce websites (for example, through vulnerabilities in CMSs like Magento or WordPress). The code intercepts card details entered by the user.
  • Example: In 2024, the Magecart campaign attacked over 12,000 websites using Stripe frames to intercept data.
• Phishing:
  • Fake websites or emails enticing users to enter card details.
• Database hacking:
  • Hackers steal card data from poorly secured retailer or payment processing company databases. For example, the Ticketmaster breach in 2024 affected millions of cards.

2.3. Internal threats​

• Bank or retail employees may leak card data to the darknet. For example, in 2025, "insider" dumps from US banks appeared on forums like BidenCash.

3. How is data encrypted and transmitted on the darknet?​

Once stolen, the magnetic stripe data is converted into a transferable format and distributed via the darknet. Here's how it works:

3.1. Coding​

• Dump format:
  • Track data (Track 1/2) is saved in text format (raw dumps). Example:
    

    %B1234567890123456^DOE/JOHN^2505101xxxxxx?
    ;1234567890123456=2505101xxxx?

  • To hide data from simple analysis, it can be encoded in Base64 or another obfuscation format.
• Tools:
  • Hardware encoders such as the MSR605X or MSR206 are used to read and write data to magnetic stripes.
  • Software such as Track1 Generator or Dump Analyzer decodes and verifies the data.
• Fullz:
  • If additional information (name, address, CVV2, SSN) is added to the stripe data, it's called "fullz." This is more expensive because it allows for online transactions.

3.2. Transmission​

• Darknet platforms:
  • The data is sold on darknet forums and marketplaces such as BidenCash , Joker's Stash (before its closure in 2021), and UniCC. In 2025, BidenCash released over 1 million dumps for free to attract customers.
  • Access is via Tor or I2P to ensure anonymity.
• Encryption:
  • Sellers use PGP (Pretty Good Privacy) to encrypt communications and dump files.
  • Escrow is often used in transactions to minimize the risk of fraud between the seller and the buyer.
• Sales format:
  • Dumps are sold individually ($5-$25 per card) or in bulk (thousands of cards for $100-$1000).
  • The price depends on:
    • Card countries (USA is more expensive, Europe is cheaper due to EMV).
    • "Freshness" (recently stolen data is valued higher).
    • Validity (verified cards with high balances).

3.3. Validation​

• Buyers use checkers (automated scripts) to verify whether a card is active. These checkers process microtransactions (e.g., $1) through dummy merchants to avoid suspicion.
• Example: In 2024, checkers using outdated Stripe APIs for card validation were distributed on the darknet.

4. Use of stolen data​

After purchasing dumps, scammers use them for various purposes:

• Cloning cards:
  • Data is written onto blank plastic cards (called "white plastic") using encoders such as the MSR605X.
  • Cloned cards are used for purchases in offline stores or cash withdrawals from ATMs.
  • Equipment cost: ~$80–$200 per encoder.
• Online fraud:
  • If CVV2 and other data (fullz) are available, cards are used for online purchases, especially on sites with a low level of security (without 3D-Secure).
• Resale:
  • Dumps can be resold to other scammers or used in "carding" schemes (mass purchases with stolen cards).
• Cashing out:
  • Through front men (drops), money is withdrawn from ATMs or transferred through cryptocurrency exchanges.

Cost: According to the Nilson Report, global losses from card fraud will be $35.79 billion in 2024, with dumps accounting for a significant portion of that.

5. Why does the technology remain relevant?​

Although chip cards (EMV) with dynamic cryptograms reduce the vulnerability of magnetic stripes, "bar coding" remains popular for several reasons:

• US: Magnetic stripes are still used because the transition to EMV is not complete (about 20% of POS terminals in the US in 2025 will only support the stripe).
• Developing countries: In some regions (such as Asia or Latin America), magnetic stripes remain the primary standard.
• Online Fraud: Even without physical cloning, Track 2 data can be used to attack legacy systems.

6. Risks and protective measures​

Risks for users​

• Financial losses due to unauthorized transactions.
• Personal data leakage (fullz), which may lead to identity theft.
• Reputational risks for businesses if their customers are harmed.

Risks to business​

• Retailers are losing customer trust due to leaks.
• Violation of PCI DSS (Payment Card Industry Data Security Standard) standards may result in fines.
• Increased chargebacks, which increases costs.

Protective measures​

1. For users:
   • Use chip cards (EMV) or contactless payments (NFC).
   • Enable two-factor authentication (2FA) for online transactions (e.g. 3D-Secure).
   • Regularly check your bank statements for suspicious transactions.
   • Avoid suspicious ATMs or terminals (check for skimmers).
   • Use darknet monitoring services (such as Have I Been Pwned or Cybersixgill) to check for leaks.
2. For business:
   • Comply with PCI DSS standards: encrypt card data, use tokenization.
   • Implement anti-skimming solutions such as Secure Web Gateways or WAFs (Web Application Firewalls).
   • Update your payment APIs (e.g. avoid legacy Stripe API).
   • Use machine learning to detect suspicious transactions (e.g. Fraud Detection Systems).
3. At the state level:
   • Accelerating the transition to EMV and abandoning magnetic stripes.
   • Tightening penalties for carding and dump trading.

7. Technological and social aspects in 2025​

• Technological trends:
  • Automated platforms (bots for mass card validation) are becoming increasingly popular on the darknet.
  • Using AI to create more sophisticated skimmers and phishing pages.
  • Growth of cryptocurrency transactions for dump payment (Bitcoin, Monero).
• Social aspects:
  • Darknet forums like BidenCash actively promote free dump giveaways to attract new users.
  • The growth in the number of "newbies" in carding due to the availability of tools (for example, ready-made skimmers for $50-100).
  • Increased attacks on small businesses that cannot afford expensive security systems.

8. Conclusion​

Darknet barcoding is the process of stealing, encoding, and transmitting magnetic stripe data from cards for fraudulent purposes. It includes physical (skimmers) and digital (web skimming) theft methods, encoding into text dumps, and sale through anonymous darknet platforms. Despite the transition to EMV, the technique remains relevant due to legacy systems and human error. Protection requires a combination of technological solutions (chips, tokenization, 2FA) and user vigilance.

If you have specific questions or need further insight into a particular aspect (for example, technical details of encoding or attack examples), let me know!