Cybercriminals are using brute-force password attacks to gain administrative access to sites using Magento's open source e-commerce platform in order to steal credit card numbers and distribute cryptocurrency mining malware, Flashpoint warned this week.

In a report Monday, the security vendor said it is aware of at least 1,000 Magento sites that appear to have been recently compromised by attackers using common and default credentials to brute force their way into the content management system (CMS) admin panel. In many cases, their task appears to have been simplified by admins who had failed to change default credentials to the platform, Flashpoint said. According to the vendor, it is quite likely the 1,000 compromised panels that it is aware of are only a subset of a larger body of compromised Magento websites.

The attackers have been using their admin access to inject malicious code into the Magento system for accessing pages and for intercepting requests to the server involving payment card data. In many cases, they have also carried out other opportunistic attacks.

Vitali Kremez, director of research for Flashpoint, says the company obtained 1,000 compromised Magento CMS panels from a Russian-speaking criminal. The threat actor was able to procure access to the panels through brute-force attacks, he says. "The actor targeted several different sectors, including education and healthcare," Kremez notes. "The IP addresses associated with the compromised panels map predominantly to Europe and the United States."

He describes the types of compromised websites as ranging from small to midsize organizations that had installed the Magento CMS for e-commerce transactions. Online retail stores appear to have been the mostly heavily affected, followed by healthcare and education websites, Kremez says.

"The actors exploit and monetize their Magento panel accesses in three unique ways depending on [the] sites," he says.

The favored way is to install JavaScript sniffers on the compromised site for scraping payment card data, which is then later sold on Dark Web stores. If the breached website does not yield payment card data, the attackers resort to uploading cryptocurrency mining tools such as Coinhive.

The third tactic is to use the compromised site to host code — typically a phony Adobe Flash Player update — which, if executed, results in a data-stealing malware tool dubbed AZORult being downloaded on computers belonging to site visitors. AZORult in turn downloads Rarog, a Coinhive cryptocurrency miner on the user's system.

The attackers have shown a tendency to update the malicious files daily in order to avoid detection by signature-based anti-malware tools, according to Flashpoint.

The discovery of the 1,000 compromised Magento websites highlights the continuing attacker interest in the platform.

"Magento CMS panels are, by far, one of the most popular e-commerce panels developed for online transactions that are heavily targeted by cybercriminals," Kremez says. Other common CMS platforms that are favored by cybercriminals, but to a lesser extent, include Powerfront and OpenCart CMS, he notes.

The recent rash of attacks is another reminder of the security risks posed by the use of default credentials by administrators. The attacks highlight the need for administrators to review the credentials that are being used to access the Magento CMS and to ensure and enforce password complexity requirements. Organizations should enable two-factor authentication for access to sensitive systems, databases, and applications, the security vendor said.

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