W32.Randex.CCF

1. Copy itself to %System%\fensvc32.exe.
   
   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).
   
   
2. Adds the value:
   
   "Fen Startups" = "fensvc32.exe"
   
   to the following registry keys:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
   
   so that it is executed every time Windows starts.
   
   
3. Spreads to hosts with randomly generated IP addresses by exploiting the following vulnerabilities:
   
   • The DCOM RPC vulnerability (described in Microsoft Security Bulletin MS03-026).
   • The Microsoft Windows Local Security Authority Service Remote Buffer Overflow (described in Microsoft Security Bulletin MS04-011).
   • Network shares that are not password-protected.
     
     
4. Opens a back door by connecting to an IRC server on the domain infected.1.vg, via TCP port 9000. It will listen for commands to perform the following actions:
   
   • Scan for computers with weak administrator passwords and copy itself to those computers.
   • Collect CD keys of many computer games and send them back to the attacker, via the IRC channel.
   • Display information about the computers, such as CPU speed and memory.
   • Perform ping, SYN, and UDP flooding.
   • Download and execute files, which may include updated versions of the worm.
   • Act as a proxy for SOCKS, HTTP, and TCP.
   • Start, stop, and delete services.
   • Log keystrokes.
     
     
5. Sends large amounts of traffic to the following hosts, apparently to measure the speed of the network connection:
   
   • de.yahoo.com
   • nitro.ucsc.edu
   • verio.fr
   • www.1und1.de
   • www.belwue.de
   • www.burst.net
   • www.cogentco.com
   • www.level3.com
   • www.nocster.com
   • www.rit.edu
   • www.schlund.net
   • www.stanford.edu
   • www.switch.ch
   • www.utwente.nl
   • www.verio.com
   • www.xo.net
     
     
6. Terminates processes, some of which may be related to security and antivirus programs. Refer to the Additional Information section below for more information.
   
   
7. Overwrites the file, %System%\drivers\etc\hosts, with the following lines to disable access to the security-related hosts listed:
   
   127.0.0.1 www.trendmicro.com
   127.0.0.1 trendmicro.com
   127.0.0.1 rads.mcafee.com
   127.0.0.1 customer.symantec.com
   127.0.0.1 liveupdate.symantec.com
   127.0.0.1 us.mcafee.com
   127.0.0.1 updates.symantec.com
   127.0.0.1 update.symantec.com
   127.0.0.1 www.nai.com
   127.0.0.1 nai.com
   127.0.0.1 secure.nai.com
   127.0.0.1 dispatch.mcafee.com
   127.0.0.1 download.mcafee.com
   127.0.0.1 www.my-etrust.com
   127.0.0.1 my-etrust.com
   127.0.0.1 mast.mcafee.com
   127.0.0.1 ca.com
   127.0.0.1 www.ca.com
   127.0.0.1 networkassociates.com
   127.0.0.1 www.networkassociates.com
   127.0.0.1 avp.com
   127.0.0.1 www.kaspersky.com
   127.0.0.1 www.avp.com
   127.0.0.1 kaspersky.com
   127.0.0.1 www.f-secure.com
   127.0.0.1 f-secure.com
   127.0.0.1 viruslist.com
   127.0.0.1 www.viruslist.com
   127.0.0.1 liveupdate.symantecliveupdate.com
   127.0.0.1 mcafee.com
   127.0.0.1 www.mcafee.com
   127.0.0.1 sophos.com
   127.0.0.1 www.sophos.com
   127.0.0.1 symantec.com
   127.0.0.1 securityresponse.symantec.com
   127.0.0.1 www.symantec.com

Recommendations

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

• Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
• 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.
• Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
• Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
• Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
• Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
• If a 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.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate compromised computers quickly to prevent threats from spreading further. 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 Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
• For further information on the terms used in this document, please refer to the Security Response glossary.