It's a hoax that has had a recent resurgence. The file is a legitimate Windows file that is used to restore long file names.
It is true that this file can become infected or "carry" the magistr virus, but unless you have had that infection identified by an antivirus scanner, just ignore the e-mail.
http://www.symantec.com/avcenter/venc/data/sulfnbk.exe.warning.html
It is true that this file can become infected or "carry" the magistr virus, but unless you have had that infection identified by an antivirus scanner, just ignore the e-mail.
http://www.symantec.com/avcenter/venc/data/sulfnbk.exe.warning.html