Troj/Psyme-CY is a downloading Trojan for the Windows platform.
Troj/Psyme-CY attempts to exploit the ADODB stream vulnerability associated with Microsoft Internet Explorer to download and execute a file from a remote website to <Temp>\bl4ck.com . At the time of writing the downloaded file is detected as Troj/Tiotua-A.
For more details about this vulnerability see the following security bulletin:
http://www.microsoft.com/technet/security/Bulletin/MS06-014.mspx.