Apple on Friday issued a second software update to address a security flaw on its OS X operating system that has allowed a massive botnet to form. The update, “Java for OS X 2012-002,” is only available for desktop and laptop PCs running OS X Lion 10.7; Apple issued a similar update last week for both Lion and Snow Leopard, and the exploit was seemingly addressed properly the first time on the Snow Leopard OS. Russian anti-virus experts revealed earlier this week that the “Flashback” trojan virus had utilized a Java vulnerability to infect more than 600,000 Mac computers worldwide. The trojan is capable of intercepting sensitive data such as passwords and other personal information, and transmitting the data back to a host. A separate firm later published instructions detailing how to detect and remove the virus, and Apple’s new update should be the last step in protecting its systems from further attacks. Apple had not yet published details surrounding the new update on its website at the time of this writing.