For the past several weeks, Magento stores have been injected with malware via a supply chain attack that targeted the FishPig distribution server.
Specialized in Magento optimizations and Magento-WordPress integrations, FishPig offers various Magento extensions that have gathered over 200,000 downloads.
On Tuesday, FishPig warned of an intrusion to its extension license system, which resulted in a threat actor injecting malicious PHP code into the Helper/License.php file.
“This file is included in most FishPig extensions so it is best to assume that all FishPig modules had been infected,” FishPig announced.
According to the company, the hackers likely had access to its servers since at least August 6.
The injected code would install another piece of malware, called Rekoobe, which hides itself as a background process on the compromised servers, according to security researchers with Sansec, who identified the intrusion.
The malicious code injected into License.php would download a Linux binary from license.fishpig.co.uk each time the Fishpig control panel is accessed in the Magento backend, Sansec explains. Named ‘lic.bin’, the downloaded file poses as a license asset, but it is, in fact, the Rekoobe remote access trojan.
After execution, the trojan removes all malicious files from the infected machine, but it remains running in memory, where it mimics a system service, while waiting for instructions from its command and control (C&C) server, the researchers note.
FishPig says it has removed the malicious code from its servers and has issued updates for all modules.
“It is recommended to upgrade all FishPig modules, or reinstall existing versions from source, regardless of whether or not you are using extensions known to be infected. This will ensure clean and secure code on your system,” FishPig announced.
Related: Vulnerability in BackupBuddy Plugin Exploited to Hack WordPress Sites
Related: Web Skimmer Injected Into Hundreds of Magento-Powered Stores
Related: Hundreds of Magento Stores Hacked Daily in Major Skimming Campaign