The first computer virus found in a digital photo was the Mocmex virus, discovered in February 2008. It was a Trojan that collected passwords for online games and was able to recognize and block antivirus protection from more than a hundred security companies and the Windows built-in firewall. Mocmex downloaded files from remote locations and hid randomly named files on infected computers, making it difficult to remove. It also spread to other portable storage devices that were plugged into an infected computer. The virus was traced back to a group in China, and industry experts described the writers of the Trojan Horse as professionals and Mocmex as a "nuclear bomb of malware". To protect against Mocmex, it is important to update antivirus software and scan digital photo frames for malware on a Macintosh or Linux machine before plugging it into a computer with Windows, or disable autorun on Windows.