Linux/Rst-B is a virus that will attempt to infect all ELF executables in the current working directory and the directory /bin.

If the virus is executed by a privileged user then it may attempt to create a backdoor on the system. This is achieved by opening a socket and listening for a particular packet containing details about the origin of the attacker and the command the attacker would like to execute on the system.

More information can be found at this Sophos page.