[quote="Symantec""]
When W32.Pasobir is executed, it performs the following actions:
Creates the following files, setting the attributes of the above files to System and Hidden to avoid easy detection:
%System%\SVOHOST.exe - copy of the worm
%System%\winscok.dll
Note: %System% is a variable that refers to the System folder. By default this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
Adds the value:
"SoundMam" = "%System%\SVOHOST.exe"
to the registry subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
so that it runs every time Windows starts.
Attempts to disable antivirus products by ending predetermined processes, removing predetermined registry keys, and stopping predetermined services.
Periodically checks for both fixed and removable drives starting with drive D: that are attached to the system and copies itself as the following file:
[DRIVE LETTER]:\sxs.exe
Creates the following file containing instructions to start the worm when the drive is attached to the system:
[DRIVE LETTER]:\autorun.inf
Attempts to record logins and passwords used in QQ messenger and send them to a preconfigured Web site or by email using its own SMTP engine.
May download and execute the following files:
[http://]update.cd321.net/si[REMOVED]
RecommendationsSymantec 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 (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
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.
[/quote]
Si es el caso, enviadnos ficheros de referencia al pasobir para analizar y lo controlaremos con nuestras utilidades
saludos
ms, 18-06-2007
msc hotline sat Virus Research Engineer 
