Technical Details :
When it is activated, Backdoor.Easyserv does the following:

It listens on port 5558 for a connection. Once connected, the attacker can direct Backdoor.Easyserv to activate an HTTP server that will show the directory structure of any local hard disk.

The HTTP server will allow the attacker to connect to the host machine using an Internet browser. Through the browser, the attacker can browse the host computer and download files from it.

Backdoor.Easyserv creates the string value

easyServ <path to server.exe>\Server.exe

under the registry key

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

Backdoor.Easyserv does not display any indication that it is running. You can verify that the Trojan is running by opening the Task list (Ctrl+Alt+Del), where you'll see the name of the running Trojan in the list. The name of the Trojan is usually Server.exe (see note that follows). You can remove Backdoor.Easyserv from memory by selecting Server.exe and then clicking End Task.

NOTE: Server.exe is the default name for Backdoor.Easyserv, but the attacker can change it to any file name.

Recommendations :
Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

If you would like to learn more about this virus please see either of the following sites: Symantec, McAfee