How one Microsoft engineer thwarted a global Linux hack

Earlier this year Andres Freund, a German software developer working for Microsoft, noticed that logging into his Linux distribution (an open source software used in most of the world’s servers) was slower than usual – half a second slower. His interest piqued, Freund found malware that had been meticulously installed in a Linux tool called xz Utils over the course of two years. The patient hacker – known only as Jia Tan – had spent years building credit as a developer to gain high-level access to the source code. This back door could have given an attacker access to hundreds of millions of computers. Freund raised the alarm last week, possibly preventing one of the worst-ever cyber attacks. He told the New York Times he was working so hard helping to reverse-engineer the hack that he hadn’t had time to have a celebratory drink.