Recently, we found a simple malicious downloader that downloads a fake PDF file. Unlike a normal malicious loader that integrates the PE Loader code into its binary, this loader has stripped this part and has turned to fetching it online.
more here.........http://blog.fortinet.com/post/the-malicious-loader-from-the-cloud
more here.........http://blog.fortinet.com/post/the-malicious-loader-from-the-cloud