readme.rtf definition, relationships, removal:

Remote Control file is an essential part of a particular parasite and therefore is responsible for the pest's malicious activity. Exact purposes of readme.rtf depend on the related parasite's type and carried payload. Some threats can use readme.rtf to serve annoying pop-up advertisements or store certain configuration settings, while others need it to corrupt files, steal user confidential information or run a spreading routine. In any case, DO NOT open this file!
The readme.rtf file is installed and used by keylogger Informer. It is also related to other parasites such as Anal Rape 1.0a, Black Angel, DeepThroat, Fraggle Rock, Remote Control and Remote Windows Shutdown. These threats can use readme.rtf for different purposes, as the file's functionality depends on a particular parasite it belongs to.
Please note that the readme.rtf file actually may be a fully legitimate part of the operating system or legitimate software. Often parasites use files with unsuspicious names, but malicious functionality. You should always carefully check the file before deleting it. It may not be related with malware, but can be required by your essential programs to work properly.