Code from a five-year-old backdoor program used on Windows has been integrated in a spyware program designed to compromise Mac OS X systems.Researchers analyzing the OS X-ready malware, dubbed XSLCmd, discovered that the sample was verified on VirusTotal on August 10, when none of the engines available were able to detect it; this is a well-known practice of malware authors.FireEye says that the piece is compatible with PowerPC and 64/86-bit CPU architectures; apart from the installation routi…