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Discovered: July 23, 2010
Updated: April 23, 2015 11:10:35 AM
Type: Worm
Infection Length: 113,664 bytes
Systems Affected: Windows
CVE References: CVE-2010-2568

W32.Changeup.C is a worm that spreads through removable and shared drives by exploiting the Microsoft Windows Shortcut 'LNK' Files Automatic File Execution Vulnerability (BID 41732).

Malicious Link Files
Symantec Endpoint Protection (SEP) users can leverage the Application and Device Control Policy feature to block malicious LNK files using details from here .

AutoRun and W32.Changeup
Symantec strongly recommends that customers take specific steps to control the execution of applications referenced in autorun.inf files that may be located on removable and network drives. Threats such as this one frequently attempt to spread to other computers using these avenues. Configuration changes made to a computer can limit the possibility of new threats compromising it.

For more information, see the following resource:
Prevent viruses from using AutoRun to spread

Symantec Endpoint Protection – Application and Device Control Policy
Symantec Security Response has developed an Application and Device Control (ADC) Policy for Symantec Endpoint Protection to protect against the activities associated with this threat. ADC policies are useful in reducing the risk of a threat infecting a computer, the unintentional removal of data, and to restrict the programs that are run on a computer.

This particular ADC policy can be used to help combat an outbreak of this threat by slowing down or eliminating its ability to spread from one computer to another. If you are experiencing an outbreak of this threat in your network, please download the policy .

To use the policy, import the .dat file into your Symantec Endpoint Protection Manager. When distributing it to client computers, we recommend using it in Test (log only) mode initially in order to determine the possible impacts of the policy on normal network/computer usage. After observing the policy for a period of time, and determining the possible consequences of enabling it in your environment, deploy the policy in Production mode to enable active protection.

For more information, please read Preventing viruses using "autorun.inf" from spreading with "Application and Device Control" policies in Symantec Endpoint Protection (SEP) 11.x and 12.1.x

For more information on ADC policies and how to manage and deploy them throughout your organization, please refer to the Symantec Endpoint Protection Administration Manual (PDF).

Note: The ADC policies above have been developed by Security Response for use in outbreak situations. While useful in such situations, due to their restrictive nature they may cause disruptions to normal business activities.

Symantec recommends proactively carrying out a number of steps to improve security in your environment. Please see Symantec Endpoint Protection – Best Practices .

Other resources

For more information, please see the following resource:

Antivirus Protection Dates

  • Initial Rapid Release version July 23, 2010 revision 003
  • Latest Rapid Release version July 26, 2019 revision 017
  • Initial Daily Certified version July 23, 2010 revision 024
  • Latest Daily Certified version July 27, 2019 revision 002
  • Initial Weekly Certified release date July 28, 2010

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Technical Description

When the worm executes, it copies itself to the following location:
%UserProfile%\[RANDOM FILE NAME].exe

Next, the worm creates the following registry entry so that it executes whenever Windows starts:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\"[RANDOM FILE NAME]" = "%UserProfile%\[RANDOM FILE NAME].exe"

It then modifies the following registry entry in order to hide itself:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\"ShowSuperHidden" = "0"

Next, the worm then attempts to download files from the following remote locations, which may be updates of itself:

  • ns[ONE NUMBER].mysearchhere.net
  • ns[ONE NUMBER].searchhereonline.net
  • ns[ONE NUMBER].theimageparlour.net
  • ns[ONE NUMBER].thepicturehut.net

Note: [ONE NUMBER] denotes a single digit from 1 to 4 inclusive.

It may then attempt to connect to one or more of the following locations:
  • codeconline.net
  • imagehut2.cn
  • msdip.com
  • peazoom.com
  • thethoughtzone.net
  • usezoom.com
  • vrera.com
  • zoomslovenia.com

The worm attempts to spread by copying itself to removable and network shared drives as the following files:
  • %DriveLetter%\[RANDOM FILE NAME].exe
  • %DriveLetter%\[RANDOM FILE NAME].scr

It also creates the following files on the same drives:
  • %DriveLetter%\autorun.inf
  • %DriveLetter%\x.exe
  • %DriveLetter%\New Folder.lnk
  • %DriveLetter%\Passwords.lnk
  • %DriveLetter%\Documents.lnk
  • %DriveLetter%\Pictures.lnk
  • %DriveLetter%\Music.lnk
  • %DriveLetter%\Video.lnk
  • %DriveLetter%\[RANDOM FILE NAME].dll
  • %DriveLetter%\[RANDOM FILE NAME].lnk
  • %DriveLetter%\[THREE RANDOM CHARACTERS].dll
  • %DriveLetter%\[THREE RANDOM CHARACTERS].lnk
  • %DriveLetter%\[EXISTING FOLDER NAME].lnk

Note: [EXISTING FOLDER NAME] denotes the names of multiple folders that exist in the root folder of %SystemDrive%.

The worm then sets the Hidden attribute on the root folder of the above drives.

The .lnk files use the Microsoft Windows Shortcut 'LNK' Files Automatic File Execution Vulnerability (BID 41732) to execute [RANDOM FILE NAME].dll.


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.


You may have arrived at this page either because you have been alerted by your Symantec product about this risk, or you are concerned that your computer has been affected by this risk.

Before proceeding further we recommend that you run a full system scan . If that does not resolve the problem you can try one of the options available below.

If you are a Norton product user, we recommend you try the following resources to remove this risk.

Removal Tool

If you have an infected Windows system file, you may need to replace them using from the Windows installation CD .

How to reduce the risk of infection
The following resources provide further information and best practices to help reduce the risk of infection.

If you are a Symantec business product user, we recommend you try the following resources to remove this risk.

Identifying and submitting suspect files
Submitting suspicious files to Symantec allows us to ensure that our protection capabilities keep up with the ever-changing threat landscape. Submitted files are analyzed by Symantec Security Response and, where necessary, updated definitions are immediately distributed through LiveUpdate™ to all Symantec end points. This ensures that other computers nearby are protected from attack. The following resources may help in identifying suspicious files for submission to Symantec.

Removal Tool

If you have an infected Windows system file, you may need to replace them using from the Windows installation CD .

How to reduce the risk of infection
The following resource provides further information and best practices to help reduce the risk of infection.
Protecting your business network

The following instructions pertain to all current Symantec antivirus products.

1. Performing a full system scan
How to run a full system scan using your Symantec product

2. Restoring settings in the registry
Many risks make modifications to the registry, which could impact the functionality or performance of the compromised computer. While many of these modifications can be restored through various Windows components, it may be necessary to edit the registry. See in the Technical Details of this writeup for information about which registry keys were created or modified. Delete registry subkeys and entries created by the risk and return all modified registry entries to their previous values.

Writeup By: Takashi Katsuki