Backdoor.Win32.Seed is the definition of a backdoor Trojan. Its first known detection goes back to February 7, 2005, according to Securelist (Kaspersky Labs). Meanwhile, there are several variants of this malware, that do not self-replicate.
Backdoor.Win32.Seed is spread manually, often under the premise that the .exe file is something beneficial. Distribution channels include IRC, peer-to-peer networks, newsgroup postings and e-mails.
Other aliases
References
Backdoor.Win32.Seed Wikipedia(Text) CC BY-SA