Customers of storage and networking equipment manufacturer Buffalo who downloaded certain files from the company's website in Japan last week might have had their computers infected with an online banking Trojan.
In a security notice published Monday, Buffalo warned customers that someone had tampered with 10 files offered for download from its site between 6:16 a.m. and 1 p.m. on May 27.
The rogue files included firmware updates, drivers and other utilities for the company's wireless LAN, network attached storage, external hard disk drive and mouse products. The complete list of malicious downloads is: airnavi2_160.exe, airnavilite-1330.exe, airnavi-1272.exe, airnavi-1040.exe, airnavi-1030.exe, kokiinst-160.exe, drivenavi_cbu2_100.exe, ls_series-168.exe, hp6v131.exe and bsbt4d09bk_21630.exe.
According to security researchers from Symantec, the files were modified to install a Trojan program called Bankeiya.B that monitors and steals information specific to Japanese online banking sites. The same malware was also distributed in Japan last month through drive-by download attacks exploiting a vulnerability in Flash Player that had been patched by Adobe on April 28.
The malware Bankeiya.B works on Windows XP, Windows Vista and Windows 7 OSes and can monitor online banking sessions in Google Chrome, Mozilla Firefox and Internet Explorer.
The malicious files placed by attackers on the Buffalo website were downloaded 856 times from 540 unique IP addresses, the Symantec researchers said Monday in a blog post. This incident highlights that attackers don't necessarily need to exploit vulnerabilities in order to infect users visiting compromised websites, they said.
Buffalo is still investigating how hackers managed to replace the legitimate files on its site with malicious versions and apologized to customers for the incident.
The company is not the first hardware manufacturer to have its site used for malware attacks against customers. In 2009, security researchers from Trend Micro found that device drivers distributed by gaming peripheral manufacturer Razer through its support site contained malware.
Other similar incidents include the compromise of a Korean SourceForge mirror in 2012 to distribute a back-doored version of the popular phpMyAdmin software.