The file in question is a named AmpleGuitarM3.5.0_DownloadPirate.com.rar . The name clearly suggests it's an installer for Ample Guitar M III, provided by a site called DownloadPirate.com . This plugin, developed by Ample Sound Technology Co., Ltd., is a sophisticated virtual instrument that realistically emulates a steel-string acoustic guitar. The official version is a paid product, so any free download from a third-party source like this should immediately raise a red flag.