Microsoft already announced the availability of Windows 7 RC. But various torrent trackers are offering leaked Windows 7 RC and have been infected with a Trojan that, if allowed to run successfully, could open a security hole in a user’s system.
The affected torrents have the setup.exe install file encapsulated in a self-extracting archive, along with an installer for the Trojan itself; launching it triggers an install of both Windows 7 RC and the malware.
So I suggest avoiding downloading such leaked builds including interim builds as well. It may cause serious problem of data lose. Far safer, however, is to wait for the official RC build, which is reportedly imminent.