W32.Areq

SUMMARY

W32.Areq is a virus that copies itself as:

• A:Fotos.exe
• C:Windows\_.exe

It also attempts to perform several actions if it is executed as A:Fotos.exe on any of these dates:

• August 30, 2001
• October 15, 2001
• November 15, 2001
• December 2, 2001
  

Protection

• Virus Definitions (LiveUpdate™ Weekly) August 22, 2002
• Virus Definitions (Intelligent Updater) August 22, 2002

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low
• Payload Trigger: August 30, 2001, October 15, 2001, November 15, 2001, December 2, 2001
• Modifies Files: Attempts to modify files to insert text. On December 2, 2001 the virus attempts to insert code to format the C-Drive into "C:autoexec.bat"

Distribution

• Distribution Level: Low

TECHNICAL DETAILS

When W32.Areq runs,

• If it runs as A:Fotos.exe, it creates the C:Windows\_.exe file.
• If it runs as C:Windows\_.exe, it attempts to create A:Fotos.exe.

When the virus runs as A:Fotos.exe
It performs these actions:

• It modifies the file C:WindowsWin.ini to read:
  
  [windows]
  run=C:WINDOWS\_.EXE
  <original contents of the file>

• It attempts to perform different actions, depending on the date on which it runs:
  
  August 30, 2001
  It attempts to create a file with the .dll extension in the C:WindowsEcritorio folder. The file contains this text:
  
  yacos1980@mixmail.com solo si te quieres salvar
  rem ___vas a perder____
  rem ___de esta nadie te salva Arequipa - Perú____
  rem ___solo para relajarme____
  rem _se hacerca el dia de formatear
  
  October 15, 2001
  It attempts to create a file with the .dll extension in the C:Windows folder. The file contains this text:
  
  rem ___vas a perder____
  rem ___de esta nadie te salva Arequipa - Perú____
  rem ___solo para relajarme____
  rem _se hacerca el dia de formatear
  
  November 15, 2001
  It attempts to create a file with the .yacos extension in the C:WindowsSystem folder. The file contains this text:
  
  rem ___Echo Por Yacos____
  rem ___Echo en Arequipa - Perú____
  rem ___Echo en un momento de Relax____
  rem _Muy pronto seras eliminado
  
  December 2, 2001
  It attempts to open C:Autoexec.bat to insert commands that format drive C.

Recommendations

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.

REMOVAL

NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Update the virus definitions, run a full system scan, and delete all files that are detected as W32.Areq.
2. On Windows 95/98/Me computers, delete the line
   
   run=C:WINDOWS\_.EXE
   
   from the Win.ini file.
   

For details on how to do this, read the following instructions.

To scan for and delete the infected files:

1. Obtain the most recent virus definitions. There are two ways to do this:
   • Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
   • Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions have undergone full quality assurance testing by Symantec Security Response. They are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.
     
     Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.
     
2. Start your Symantec antivirus program, and make sure that it is configured to scan all files.
   • Norton AntiVirus consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • Symantec enterprise antivirus products: Read the document How to verify a Symantec Corporate antivirus product is set to scan All Files.
3. Run a full system scan.
4. If any files are detected as infected with W32.Areq, click Delete.

To remove the line that the virus added to the Win.ini file:

NOTE: (For Windows Me users only) Due to the file-protection process in Windows Me, a backup copy of the file that you are about to edit exists in the C:WindowsRecent folder. Symantec recommends that you delete this file before you continue with the steps in this section. To do this using Windows Explorer, go to C:WindowsRecent, and in the right pane select the Win.ini file and delete it. It will be regenerated as a copy of the file that you are about to edit when you save your changes to that file.

1. Click Start, and click Run.
2. Type the following, and then click OK.
   
   edit c:windowswin.ini
   
   The MS-DOS Editor opens.
   
   NOTE: If Windows is installed in a different location, make the appropriate path substitution.
   
3. In the [windows] section of the file, look for the line
   
   run=C:WINDOWS\_.EXE
   
4. If the line exists, select the entire line. Be sure that you do not select any other text, and then press Delete.
5. Click File, and click Save.
6. Click File, and click Exit.