I want to tell you a story, two days back i got affected by this virus very badly as it eat up all my empty hard disk space of around 700 MB :( . I was surprised that my most reliable friend Avast, for the first time failed me in this war against viruses but then again avg and bitdiffender also failed against it. This virus is know popularly as regsvr.exe virus, or as new folder.exe virus and most people identify this one by seeing autorun.inf file on their pen drives, But trend micro and symantec identified it as WORM_DELF.FKZ. and trojen dropper It is spreading mostly using this pen drives as the medium.