In recent years, e-commerce security has become a top priority for online businesses. As cybercriminals continue to evolve their tactics, they are finding new ways to bypass traditional security measures. One particularly alarming method is the use of malicious image tags to steal sensitive payment information. In this article, we will delve into how this skimming attack works, why it is difficult to detect, and what e-commerce businesses can do to protect themselves.
What Are Malicious Image Tags?
The key exploit here is the use of the onerror event, a common HTML attribute usually used to handle errors when an image cannot load. Attackers take advantage of this functionality by injecting malicious code into the onerror handler. When a user lands on the checkout page, the malicious code activates and starts stealing payment data like credit card numbers, expiration dates, and CVV codes—without the user’s knowledge.
How Malicious Image Tags Bypass E-commerce Security
While most e-commerce businesses use a variety of security tools—such as firewalls, anti-malware software, and intrusion detection systems—malicious image tags often bypass these defenses for several reasons:
1. Invisible to Scanners
Traditional e-commerce security scanners are designed to detect known malware signatures or suspicious behavior. However, because the malicious code is hidden within an image tag, it appears harmless. This invisibility allows the skimmer to evade detection for extended periods.
2. Use of Legitimate Code
The attacker doesn’t introduce unfamiliar code but rather exploits legitimate HTML and JavaScript functions that are already in place. This makes it harder for security tools to identify abnormal behavior, as it uses standard HTML attributes and doesn’t trigger alarms like external JavaScript files would.
3. External Server Communication
The stolen payment data is sent directly to an external server controlled by the hacker, bypassing the need to store this information on the website’s server. Since the e-commerce site itself doesn’t hold the data, it’s harder to track the breach until the data is already compromised.
4. Infected Third-Party Plugins and Vulnerable Software
The attack often starts with compromised third-party plugins or outdated software. Hackers exploit vulnerabilities in these areas to inject malicious code into the website’s existing infrastructure, making it difficult to detect until it’s too late.
The Role of E-commerce Platforms in Security
E-commerce platforms such as Magento, WooCommerce, and PrestaShop are frequent targets due to their widespread use. While these platforms have built-in security features, many store owners overlook regular updates and audits, leaving their websites vulnerable to new attack methods like the one described above.
For instance, outdated plugins or themes on Magento stores can create entry points for hackers to inject malicious scripts. WooCommerce and PrestaShop face similar risks, with third-party extensions acting as potential weak links. Keeping all software up to date and performing regular security audits is crucial to safeguarding your store from these types of attacks.
Best Practices for Improving E-commerce Security
Given how hard malicious image tag attacks can be to detect, e-commerce businesses must take proactive steps to protect themselves and their customers. Here are some essential e-commerce security practices every store owner should follow:
1. Conduct Regular Security Audits
Regular security audits are essential for uncovering vulnerabilities in your site’s code, third-party plugins, and server configurations. An audit can help identify and eliminate hidden threats like malicious image tags before they can be exploited.
2. Keep Software and Plugins Updated
Ensure your e-commerce platform, plugins, and any third-party extensions are always updated. Magento security patches, WooCommerce updates, and PrestaShop security fixes are released regularly, and installing them as soon as they’re available can help prevent hackers from exploiting known vulnerabilities.
3. Use a Content Security Policy (CSP)
A Content Security Policy (CSP) is a browser feature that can help prevent the execution of malicious scripts. By implementing a robust CSP, you can restrict the sources from which JavaScript is loaded, making it harder for attackers to inject malicious code.
4. Leverage Web Application Firewalls (WAFs)
A Web Application Firewall (WAF) can help block malicious traffic before it reaches your e-commerce website. Many WAFs come with rules to detect common attack vectors, including skimming attacks like the one involving malicious image tags.
5. Implement Strong Payment Security Protocols
Ensure that your payment processing system complies with the highest security standards, such as PCI-DSS compliance. Using tokenization and SSL encryption for transactions can prevent credit card information from being intercepted by hackers.
6. Monitor Checkout Pages for Suspicious Activity
Since malicious image tags typically activate on the checkout page, it’s crucial to monitor activity on this page for any unusual behavior. Real-time monitoring tools can alert you if any unauthorized scripts are executing on the checkout page.
7. Educate Your Team on Security Best Practices
Your security protocols are only as strong as the people who implement them. Educating your team about the risks of malicious code injection and how to spot vulnerabilities can significantly reduce the chances of a successful attack.
Conclusion
Malicious image tags are just one of the many ways hackers are bypassing traditional e-commerce security measures to steal sensitive customer data. As cyber threats continue to evolve, e-commerce store owners must stay vigilant and proactive in securing their websites. By keeping software up to date, conducting regular security audits, and using advanced security tools like Content Security Policies and Web Application Firewalls, you can better protect your store and your customers from these hidden threats.
For Magento, WooCommerce, and PrestaShop store owners, the best defense is a comprehensive, multi-layered security strategy that keeps hackers at bay and ensures a secure, trustworthy shopping experience for your customers.