A report on Ars Technica states that Battlefield Play4Free users who are running the game on older versions of Windows may be at risk due to an exploit. According to the report, researchers at Black Hat security conference in Amsterdam demonstrated a proof-of-concept exploit, showing who players could be lured to “a booby-trapped website” which would then allow hijackers to “execute malicious code on default systems running Windows XP or Windows 2003″ where Play4Free is installed. Upon going to the site, an MOD file filled with malicious code is loaded through the game on the computer, which then allows for a batch file to be executed once the system is restarted. While only 39% of Windows users are though to still be using XP, there are around 1 million Battlefield Play4Free users playing the game. Ars has more on the report.