Discovered: August 23, 2005
Updated: February 13, 2007 12:43:03 PM
Type: Worm
Systems Affected: Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP
When W32.Kelvir.HI is executed, it performs the following actions:
- Copies itself as %System%\msmsgr.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).
- Drops a copy of W32.Spybot.Worm as %System%\msnmsgr.exe and executes it.
- Adds the value:
"MSN Messenger User Controls" = "msmsgr.exe"
to the registry subkeys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
so that it runs every time Windows starts.
- Adds the value:
"TempData" = "[PATH TO THE ORIGINAL FILE]"
to the registry subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
as an infection marker.
- Adds the value:
"DisableTaskMgr" = "1"
"DisableRegistryTools" = "1"
to the registry subkey:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
to disable Task Manager and Registry Editor.
- Adds the value:
"DisableSR" = "1"
to the registry subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore
to disable system restore.
- Periodically inputs one of the following messages into any active window:
English:
haha i found your picture!
Spanish:
lol !Encontre su foto!
Note: The first exclamation mark(!) is inverted.
Dutch:
lol ik heb je foto gevonden
French:
haha J'ai trouve votre photo!
German:
haha Ich fand Ihr Foto!
Greek in English alphabet:
lol sou malakas!
Swedish:
haha men titta det e ju du
Italian:
haha Ho trovato la vostra foto!
Portuguese:
haha Eu encontrei sua foto!
Turkish:
Senin fotorafini buldum turkiyedeki
Note: The message is chosen based on the default system language.
- If an MSN Messenger window is open one of the above messages is sent to the contact. The message may also include the following URL, which contains a copy of the worm:
[http://]images.rottentomatoes.us/[REMOVED]/search.php?data=
- Opens a browser window displaying the following URL:
[http://]images.rottentomatoes.us/[REMOVED]/search.php?data=
Note: The URL contains a copy of the worm.
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.
Writeup By: Masaki Suenaga