Trojan.Alemod

Trojan.Alemod is a Trojan horse that infects wininet.dll and monitors all Web traffic. It also modifies the desktop setting and downloads files from the Internet.
Note: Virus definitions dated October 10th 2005 or earlier may detect this threat as W32.Desktophijack.

Type:	Trojan Horse
Infection Length:	Varies.
Systems Affected:	Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP

Virus Definitions (LiveUpdate™ Weekly) June 22, 2005 Virus Definitions (Intelligent Updater) June 20, 2005

Wild Number of infections: 0 - 49 Number of sites: 0 - 2 Geographical distribution: Low Threat containment: Easy Removal: Easy

Threat Metrics Wild: Low Damage: Low Distribution: Low

Damage

• Payload Trigger: n/a
• Payload: Infects wininet.dll.
  • Large scale e-mailing: n/a
  • Deletes files: n/a
  • Modifies files: n/a
  • Degrades performance: n/a
  • Causes system instability: n/a
  • Releases confidential info: Monitors what pages have been accessed and send the log to the predetermined web sites.
  • Compromises security settings: n/a

Distribution

• Subject of email: n/a
• Name of attachment: n/a
• Size of attachment: n/a
• Time stamp of attachment: n/a
• Ports: n/a
• Shared drives: n/a
• Target of infection: n/a

When Trojan.Alemod is executed, it performs the following actions:

1. Displays the following message:
   
   
   
   
2. Regardless of whether the user chooses YES or NO, it creates the following files:
   
   
   • %Windir%\uninstIU.exe (detected as Trojan.Desktophijack.B)
   • %System%\oleadm.dll (detected as Trojan.Desktophijack.B)
   • %System%\wp.bmp
     
     Notes:
   • %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).
   • %Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows (Windows 95/98/Me/XP) or C:\Winnt (Windows NT/2000).
     
     
3. Copies the file %System%\wininet.dll as %System%\oleadm32.dll and inserts code into %System%\oleadm32.dll.
   
   Note: The code hooks all the calls to the function HttpSendRequest and transfers them to oleadm.dll. oleadm.dll can monitor what pages have been
   accessed and send the log to the following web sites:
   
   
   • [http://]ecjnoe3inwe.com/[REMOVED]
   • [http://]fjrewcer32.com/[REMOVED]
   • [http://]dkjfwekjnc4.com/[REMOVED]
     
     
4. Adds the values:
   
   "AllowProtectedRenames" = "1"
   "PendingFileRenameOperations" = "\??\%System%\oleadm32.dll !\??\%System%\wininet.dll"
   
   to the registry subkey:
   
   HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager
   
   so that the original wininet.dll file will be replaced with oleadm32.dll after the compromised computer is restarted.
   
   
5. Adds the value:
   
   "WindowsFZ" = "[PATH TO EXECUTABLE FILE]"
   
   to the registry subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   
   so that the risk runs every time Windows starts.
   
   
6. Modifies the value:
   
   "Background" = "1 2 172"
   
   in the registry subkey:
   
   HKEY_CURRENT_USER\Control Panel\Colors
   
   to modify the desktop background color.
   
   
7. Adds the values:
   
   "WallpaperStyle" = "0"
   "Wallpaper" = "%System%\wp.bmp"
   
   to the registry subkey:
   
   HKEY_CURRENT_USER\Control Panel\Desktop
   
   to modify the desktop wallpaper.
   
   
8. Creates the following registry subkey:
   
   HKEY_CLASSES_ROOT\CLSID\{357A87ED-3E5D-437d-B334-DEB7EB4982A3}
   
   
9. Modifies the values:
   
   "NoDispAppearancePage" = "1"
   "NoDispBackgroundPage" = "1"
   
   in the registry subkey:
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
   
   
10. Modifies the value:
    
    "NoActiveDesktopChanges" = "1"
    
    in the registry subkey:
    
    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    
    
11. Adds following registry entries:
    
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Internet update
    
    
12. Changes the desktop wallpaper to an image with one of following texts:
    
    
    • Warning!
      Your computer is infected!
    • Security warning
      A fatal error in IE has occured at 0028:C0011E36 in UXD UMM01 *
      00010E36. Error was caused by Trojan-Spy.HTML.Smitfraud.c
      * System cannot function in normal mode.
      Please check your security settings.
      * Scan your PC with any available antivirus / spyware remover program to
      fix this problem.
      
      
13. Downloads and installs one of the following files:
    
    
    • [http://]206.161.200.34/[REMOVED]
    • [http://]download.psguard.com/[REMOVED]

Symantec 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.

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

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

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

• Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to Virus Definitions (LiveUpdate).
• 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. To determine whether definitions for this threat are available by the Intelligent Updater, refer to Virus Definitions (Intelligent Updater).
  
  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.
  

1. 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.
2. Run a full system scan.
3. If wininet.dll is detected, click Repair.
4. If any other files are detected, click Delete.

1. Click Start > Run.
2. Type regedit
3. 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.
   
   
4. Navigate to the subkey:
   
   HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager
   
   
5. In the right pane, delete the values:
   
   "AllowProtectedRenames" = "1"
   "PendingFileRenameOperations" = "\??\%System%\oleadm32.dll !\??\%System%\wininet.dll"
   
   
6. Navigate to the subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   
   
7. In the right pane, delete the value:
   
   "WindowsFZ" = "[path to executable file]"
   
   
8. Navigate to the subkey:
   
   HKEY_CURRENT_USER\Control Panel\Desktop
   
   
9. In the right pane, delete the values:
   
   "WallpaperStyle" = "0"
   "Wallpaper" = "%System%\wp.bmp"
   
   
10. Navigate to the subkey:
    
    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    
    
11. In the right pane, delete the values:
    
    "NoDispAppearancePage" = "1"
    "NoDispBackgroundPage" = "1"
    
    
12. Navigate to the subkey:
    
    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    
    
13. In the right pane, delete the value:
    
    "NoActiveDesktopChanges" = "1"
    
    
14. Navigate to and delete the registry keys:
    
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Internet update
    HKEY_CLASSES_ROOT\CLSID\{357A87ED-3E5D-437d-B334-DEB7EB4982A3}
    
    
15. Exit the Registry Editor.

Write-up by: Kaoru Hayashi