Topic: W32.KenetyRisk

[Samker]

W32.KenetyRisk Level 2: LowDiscovered: May 10, 2007
Updated: May 11, 2007 5:57:11 AM
Type: Worm
Infection Length: 61,952 bytes
Systems Affected: Windows 98, Windows 95, Windows XP, Windows Me, Windows NT, Windows Server 2003, Windows 2000
CVE References: CVE-2006-2369
SUMMARYW32.Kenety is a worm that opens a back door on the compromised computer and spreads by exploiting the RealVNC Remote Authentication Bypass Vulnerability (BID 17978).

ProtectionVirus Definitions (LiveUpdate™ Daily) May 11, 2007
Virus Definitions (LiveUpdate™ Weekly) May 16, 2007
Virus Definitions (Intelligent Updater) May 11, 2007
Virus Definitions (LiveUpdate™ Plus) May 11, 2007
Threat AssessmentWildWild Level: Medium
Number of Infections: 0 - 49
Number of Sites: 0 - 2
Geographical Distribution: Low
Threat Containment: Easy
Removal: Easy
DamageDamage Level: Medium
Payload: Opens a back door on the compromised computer.
Compromises Security Settings: Bypasses the Windows firewall.
DistributionDistribution Level: Medium
Ports: TCP port 8888
Target of Infection: Computers exploitable by the RealVNC Remote Authentication Bypass Vulnerability.
TECHNICAL DETAILSOnce executed, it copies itself as the following file:
%ProgramFiles%\Common Files\Systemdata\svchost.exe

The worm then modifies the following values so that it can bypass the Windows firewall:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\"%ProgramFiles%\Common Files\Systemdata\svchost.exe" = "%ProgramFiles%\Common Files\Systemdata\svchost.exe:*:Enabled:syncronization"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\"%ProgramFiles%\Common Files\Systemdata\svchost.exe" = "%ProgramFiles%\Common Files\Systemdata\svchost.exe:*:Enabled:syncronization"

The worm registers itself as a service with the following characteristics:
Display Name: Sync
ImagePath: %ProgramFiles%\Common Files\Systemdata\svchost.exe

The worm then creates registry entries for the above service under the following registry subkeys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Sysdate
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Sysdate

It ends itself if the current username contains one of the following strings:

nepenthes
currentuser
vmware
honey
sandbox
Next, the worm opens a back door on the compromised computer by connecting to one of the following servers on TCP port 8888:

hijosdelagranputa.serveftp.net
hijosdelagranputa.serveftp.com
elterryer.serveftp.net
elterryer.serveftp.com

It then awaits for commands from the remote attacker that allow it to perform the following actions:

Download updates of itself by FTP
Download and execute files from the Internet
Patch the files %System%\drivers\tcpip.sys and %System%\sfc_os.dll
The worm then starts an FTP server.

It then attempts to spread by exploiting the RealVNC Remote Authentication Bypass Vulnerability (BID 17978).

If it cannot successfully exploit the vulnerability, the worm will use the following passwords to access the RealVNC application:

king
princess
bitch
1234567
pass
root
test
super
master
help
server
secret
test123
manager
admin
password
vnc
123456
12345
1234
123
0000
1111
12345678

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.
REMOVALThe following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

Disable System Restore (Windows Me/XP).
Update the virus definitions.
Run a full system scan.
Delete any values added to the registry.

For specific details on each of these steps, read the following instructions.

1. To disable System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.

Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.

Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.

For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:

How to disable or enable Windows Me System Restore
How to turn off or turn on Windows XP System Restore

Note: When you are completely finished with the removal procedure and are satisfied that the threat has been removed, reenable System Restore by following the instructions in the aforementioned documents.

For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article: Antivirus Tools Cannot Clean Infected Files in the _Restore Folder (Article ID: Q263455).

2. To update the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:

Running LiveUpdate, which is the easiest way to obtain virus definitions.

If you use Norton AntiVirus 2006, Symantec AntiVirus Corporate Edition 10.0, or newer products, LiveUpdate definitions are updated daily. These products include newer technology.

If you use Norton AntiVirus 2005, Symantec AntiVirus Corporate Edition 9.0, or earlier products, LiveUpdate definitions are updated weekly. The exception is major outbreaks, when definitions are updated more often.



Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted daily. You should download the definitions from the Symantec Security Response Web site and manually install them.

The latest Intelligent Updater virus definitions can be obtained here: Intelligent Updater virus definitions. For detailed instructions read the document: How to update virus definition files using the Intelligent Updater.

3. To run a full system scan

Start your Symantec antivirus program and make sure that it is configured to scan all the files.

For Norton AntiVirus consumer products: Read the document: How to configure Norton AntiVirus to scan all files.

For Symantec AntiVirus Enterprise products: Read the document: How to verify that a Symantec Corporate antivirus product is set to scan all files.



Run a full system scan.
If any files are detected, follow the instructions displayed by your antivirus program.
Important: If you are unable to start your Symantec antivirus product or the product reports that it cannot delete a detected file, you may need to stop the risk from running in order to remove it. To do this, run the scan in Safe mode. For instructions, read the document, How to start the computer in Safe Mode. Once you have restarted in Safe mode, run the scan again.
After the files are deleted, restart the computer in Normal mode and proceed with the next section.

Warning messages may be displayed when the computer is restarted, since the threat may not be fully removed at this point. You can ignore these messages and click OK. These messages will not appear when the computer is restarted after the removal instructions have been fully completed. The messages displayed may be similar to the following:

Title: [FILE PATH]
Message body: Windows cannot find [FILE NAME]. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button, and then click Search.

4. To delete the value from the registry
Important: Symantec strongly recommends that you back up the registry before making any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified subkeys only. For instructions refer to the document: How to make a backup of the Windows registry.

Click Start > Run.
Type regedit
Click OK.

Note: If the registry editor fails to open the threat may have modified the registry to prevent access to the registry editor. Security Response has developed a tool to resolve this problem. Download and run this tool, and then continue with the removal.
Navigate to and delete the following entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\"%ProgramFiles%\Common Files\Systemdata\svchost.exe" = "%ProgramFiles%\Common Files\Systemdata\svchost.exe:*:Enabled:syncronization"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\"%ProgramFiles%\Common Files\Systemdata\svchost.exe" = "%ProgramFiles%\Common Files\Systemdata\svchost.exe:*:Enabled:syncronization"


Navigate to and delete the following subkeys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Sysdate
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Sysdate


Exit the Registry Editor.