W32.HLLW.Nautic

When W32.HLLW.Nautic runs, it first checks for the presence of an installed Windows Debugger. If it finds one, it exits. If it does not find one, it does the following:

If the day is December 25, the worm displays the text:

Today is Christmas day !! Yah ?? - Santa Claus [--Nautical--]

The worm checks if the current file name is one of the following:

• NTDLL.exe
• Win32.exe
• Explore.exe
• Kernel32.exe
• krnl286.exe
• Dllhost32.exe
• MSTCP.exe
• CRSS.exe
• Winlogon32.exe
• Winsrvc.exe
• Ntoskrn.exe
• Vmm32.exe
• Sysmon.exe
• System32.exe
• Sys.exe
• Win.exe
• Rundil32.exe
• Msrvcp.exe
• Msgmsr.exe
• Mscde32.exe
• Regsvclib.exe
• Reg32.exe
• Registry32.exe
• Service.exe
• Rpcsrvc.exe

If the current file name is not one of the following, it displays the following message:



It then copies itself to the %system% folder as one of the files in the previous list.

The worm then checks whether the value

Nautical

under the registry key

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion

is equal to "1".

If it is not, the worm configures itself to start when Windows starts by performing one of the following actions:

• Adding the value
  
  Run %system%\<file name from above list>
  
  to the registry key
  
  HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
  
• Adding the value
  
  System32 %system%\<file name from above list>
  
  to the registry key
  
  HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
  
• Adding the value
  
  WinSys %system%\<file name from above list>
  
  to the registry key
  
  HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
  
• Adding the value
  
  Msgsvc32 %system%\<file name from above list>
  
  to the registry key
  
  HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
  
• Adding the line
  
  run=%system%\<file name from above list>
  
  to the %windir%\Win.ini file

After it has completed these actions, it sets the value

Nautical

under the registry key

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion

to 1.
W32.HLLW.Nautic creates and shares a folder on the network. This folder is created in the %system% folder, the %windir% folder, or the %Program Files% folder. The folder name is one of the following:

• Porn Stuff
• My Personal Stuff
• Softwarez
• Cracrs_Serials
• Private - Do Not Enter
• Mp3z
• Misc Stuff
• Fun Stuff
• Pics
• Xxx Movies
• Full Vcds
• Top Secret
• My Projects
• Funny Pictures
• Nude Pics

The worm then copies itself to this folder as a file name that is designed to trick users into executing the malicious files. The following are some of the possible file names:

• Windows XP Crack.exe
• Warcraft III Trainer (Cheats).exe
• Norton Antivirus 2003 Installer.exe
• Bikini Girls.exe
• Halflife Patch.exe
• Funny Screensaver.exe
• Hack Hotmail Account.exe
• Age of Empires II_Keygen(Serial).exe
• Warcraft III - Crack.exe
• Winzip 8.2 (Beta 3) Full Version Installer.exe
• Playboy_Screensaver_Install.exe

It configure this folder to be shared on the network by adding the following registry values

Flags
Parm1enc
Parm2enc
Path <folder path from above, for example %Program Files%\NUDE PICS>
Remark
Type

to the registry key

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Network\LanMan\<folder path from above>

After the worm shares the folder, it sets the value

Nautica

under the registry key

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion

to 1.

The worm also supports certain backdoor-like functionality. It supports two different commands:

• EJECT
• UNLOAD

The EJECT function attempts to send commands to drives D through K.
The UNLOAD function closes the network connection and stops listening.

The worm listens for commands on one of the following ports:

• 335
• 2281
• 5679
• 9148

When the worm receives a connection to the port, it displays this message:



The worm propagates the command to all infected computers on a given domain by using mailslots. A mailslot is described by Microsoft as follows:

"A mailslot is a mechanism for one-way interprocess communications (IPC). Applications can store messages in a mailslot."

The worm uses this mechanism to propagate commands sent to any of the infected computers to all computers on the infected domain.

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.

Summary