Web skimming attacks target major payment networks

Online shopping feels familiar and fast, but a hidden threat continues to operate behind the scenes. Researchers are tracking a long-running web skimming campaign that targets businesses connected to major payment networks. Web skimming is a technique where criminals secretly add malicious code to checkout pages so they can steal payment details as shoppers type them in. These attacks work quietly inside the browser and often leave no obvious signs. Most victims only discover the problem after unauthorized charges appear on their statements.

What Magecart is and why it matters

Magecart is the name researchers use for groups that specialize in web skimming. Web skimming attacks focus on online stores where shoppers enter payment details during checkout. Instead of hacking banks or card networks directly, attackers slip harmful code into a store’s checkout page. That code is written in JavaScript, which is a common type of website code used to make pages interactive. Legitimate sites use it for things like forms, buttons, and payment processing.

In Magecart attacks, criminals abuse that same code to secretly copy card numbers, expiration dates, security codes, and billing details as shoppers type them in. The checkout still works, and the purchase goes through, so there is no obvious warning sign. Magecart originally described attacks against Magento-based online stores. Today, the term applies to web skimming campaigns across many e-commerce platforms and payment systems.

Which payment providers are being targeted

Researchers say this campaign targets merchants tied to several major payment networks, including:

• American Express
• Diners Club
• Discover, a subsidiary of Capital One
• JCB Co., Ltd.
• Mastercard
• UnionPay

Large enterprises that rely on these payment providers face a higher risk due to complex websites and third-party integrations.

How attackers slip skimmers into checkout pages

Attackers usually enter through weak points that are easy to overlook. Common entry paths include vulnerable third-party scripts, outdated plugins and unpatched content management systems. Once inside, they inject JavaScript directly into the checkout flow. The skimmer monitors form fields tied to card data and personal details, then quietly sends that information to attacker-controlled servers.

Why web skimming attacks are hard to detect

To avoid detection, the malicious JavaScript is heavily obfuscated. Some versions can remove themselves when they detect an admin session, which makes inspections appear clean. Researchers also found the campaign uses bulletproof hosting. These hosting providers ignore abuse reports and takedown requests, giving attackers a stable environment to operate. Because web skimmers run inside the browser, they can bypass many server-side fraud controls used by merchants and payment providers.

Who Magecart web skimming attacks affect most

Magecart campaigns impact three groups at the same time:

• Shoppers who unknowingly give up card data
• Merchants whose checkout pages are compromised
• Payment providers that detect fraud after the damage is done

This shared exposure makes detection slower and response more difficult.

How to stay safe as a shopper

While shoppers cannot fix compromised checkout pages, a few smart habits can reduce exposure, limit how stolen data is used, and help catch fraud faster.

1) Use virtual or single-use cards

Virtual and single-use cards are digital card numbers that link to your real credit or debit account without exposing the actual number. They work like a normal card at checkout, but add an extra layer of protection. Most people already have access to them through services they use every day, including:

• Major banks and credit card issuers that offer virtual card numbers inside their apps
• Mobile wallet apps like Apple Pay and Google Pay generate temporary card numbers for online purchases, keeping your real card number hidden
• Some payment apps and browser tools that create one-time or merchant-locked card numbers

A single-use card typically works for one purchase or expires shortly after use. A virtual card can stay active for one store and be paused or deleted later. If a web skimming attack captures one of these numbers, attackers usually cannot reuse it elsewhere or run up repeat charges, which limits financial damage and makes fraud easier to stop.

2) Turn on transaction alerts

Transaction alerts notify you the moment your card is used, even for small purchases. If web skimming leads to fraud, these alerts can expose unauthorized charges quickly and give you a chance to freeze the card before losses grow. For example, a $2 test charge on your card can signal fraud before larger purchases appear.

3) Lock down financial accounts

Use strong, unique passwords for banking and card portals to reduce the risk of account takeover. A password manager helps generate and store them securely.

Next, see if your email has been exposed in past breaches. Our #1 pick, NordPass, includes a built-in breach scanner that checks whether your email address or passwords have appeared in known leaks. If you discover a match, immediately change any reused passwords and secure those accounts with new, unique credentials.

4) Install strong antivirus software

Strong antivirus software can block connections to malicious domains used to collect skimmed data and warn you about unsafe websites.

The best way to safeguard yourself from malicious links that install malware, potentially accessing your private information, is to have strong antivirus software installed on all your devices. This protection can also alert you to phishing emails and ransomware scams, keeping your personal information and digital assets safe.

5) Use a data removal service

Data removal services can reduce how much personal information is exposed online, making it harder for criminals to pair stolen card data with full identity details.

While no service can guarantee the complete removal of your data from the internet, a data removal service is really a smart choice. They aren’t cheap, and neither is your privacy. These services do all the work for you by actively monitoring and systematically erasing your personal information from hundreds of websites. It’s what gives me peace of mind and has proven to be the most effective way to erase your personal data from the internet. By limiting the information available, you reduce the risk of scammers cross-referencing data from breaches with information they might find on the dark web, making it harder for them to target you.

Is your personal information exposed online?

Run a free scan to see if your personal info is compromised. Results arrive by email in about an hour.

6) Watch for unexpected card activity

Review statements regularly, even for small charges, since attackers often test stolen cards with low-value transactions.

7) Add an extra layer of protection with secure credit cards

Even with good habits, web skimming can still happen without warning. One of the strongest defenses is using credit cards that are built with security features designed to limit fraud and reduce your liability if card data is stolen.

Some of the most secure credit cards today offer protections like:

• Zero liability for unauthorized charges
• Real-time fraud monitoring with instant alerts
• Virtual card numbers that shield your real card details
• Temporary card numbers for online shopping
• Easy card locking from a mobile app
• Strong purchase protection and dispute resolution

These features make a big difference if criminals capture card data through a compromised checkout page. Instead of dealing with long cleanup headaches, secure cards help stop fraud faster and limit financial damage.

We’ve put together a list of the most secure credit cards worth having, including options from major issuers that focus heavily on fraud prevention and digital safety.

Read our full guide here

The most secure credit cards worth having

Using a secure credit card won’t stop web skimming attacks, but it can dramatically reduce the impact if your information is ever exposed.

Related Links: 

• Make 2026 your most private year yet by removing broker data
• 5 ways a VPN protects your online holiday shopping
• Why an email alias is my secret weapon for safer online shopping

Kurt’s key takeaways

Magecart web skimming shows how attackers can exploit trusted checkout pages without disrupting the shopping experience. While consumers cannot fix compromised sites, simple safeguards can reduce risk and help catch fraud early. Online payments rely on trust, but this campaign shows why that trust should always be paired with caution.

Does knowing how web skimming works make you rethink how safe online checkout really is? Let us know your thoughts in the comments below. 

FOR MORE OF MY TECH TIPS & SECURITY ALERTS, SUBSCRIBE TO MY FREE CYBERGUY REPORT NEWSLETTER HERE

Copyright 2026 CyberGuy.com.  All rights reserved.  CyberGuy.com articles and content may contain affiliate links that earn a commission when purchases are made.