W32.HLLW.Daboom@mm

SUMMARY

W32.HLLW.Daboom@mm is a mass-mailing worm that replicates by email. It sends itself to the addresses it finds in the:

• Windows Address Book
• .htm and .html files stored in the Internet Explorer cache

The email message has a subject, message, and attachment; all of which are randomly chosen. The attachment will have a .pif file extension.

W32.HLLW.Daboom@mm also contains backdoor Trojan capabilities which permit unauthorized access to an infected computer.

W32.HLLW.Daboom@mm is a Visual Basic (p-code) application packed with UPX 1.20.

Protection

• Virus Definitions (LiveUpdate™ Weekly) March 12, 2003
• Virus Definitions (Intelligent Updater) March 7, 2003

Threat Assessment

Wild

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

Damage

• Damage Level: Medium
• Large Scale E-mailing: Sends itself to the addresses it finds in the Windows Address Book and .htm and .html files stored in the Internet Explorer cache.
• Modifies Files: Modifies system registry.
• Releases Confidential Info: Intercept confidential information by hooking any keystrokes.
• Compromises Security Settings: Allows unauthorized access to an infected computer.

Distribution

• Distribution Level: High
• Subject of Email: Random
• Name of Attachment: Random name with .pif extension
• Size of Attachment: 48,128 bytes

TECHNICAL DETAILS

When W32.HLLW.Daboom@mm runs, it performs the following actions:

1. Copies itself into the %System% directory as %System%Systray32.exe.
   
   NOTE: %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:WindowsSystem (Windows 95/98/Me), C:WinntSystem32 (Windows NT/2000), or C:WindowsSystem32 (Windows XP).
   
2. Creates the value:
   
   ActiveDesktop    %system%systray32.exe
   
   in the registry key:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersion
   RunServices
   
   so that the worm starts when you start Windows.
   
3. If the operating system is Windows 95/98/Me, the worm registers itself as a service process to hide itself from the Task list.
   
4. Attempts to obtain access to the password cache stored on your computer. The cached passwords include modem and dialup passwords, URL passwords, share passwords, and others.
   
5. Intercepts information by hooking keystrokes. This permits W32.HLLW.Daboom@mm to possibly steal confidential messages when you type them.
   
6. Notifies the client side using email. Once installed, W32.HLLW.Daboom@mm waits for the commands from the remote client. The commands allow the hacker to perform any of the following actions:
   • Deliver system and network information to the hacker, including login names and cached network passwords
   • Open or close the CD-ROM drive and perform other actions
   • Download and execute files
   • Alter many system parameters
   • Inventory active windows
   • Delete files with the .doc, wri, .eml, .htm, .html, or .txt extensions
     
     
7. Sends itself to the addresses that it finds in the:
   • Windows Address Book
   • .htm and .html files stored in the Internet Explorer cache.
     
     The worm finds the location of the cache folder by reading the value: Directory
     
     from the registry key:
     
     HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersion
     Internet SettingsCachePaths

Email routine details
The email message has the following characteristics:

Subject: The subject is randomly chosen from the following list:

• Hotmail Members Service
• CD Home (El Mejor precio)
• CD Home (The best price)
• hacking
• dont read me
• No me leas
• Info
• Cartuchos HP al mejor precio
• Te dije que era gorda. Mira!
• Creí que ya lo habia enviado
• Mailer Daemon Failure - Undeliverable mail
• New on AudioGalaxy
• Por favor no me envies más mails
• Please dont send me more mails
• AudioGalaxy
• jaja se parece a tu hermana, el mejor!!!
• Jajaja
• Just testing my new mail
• Responde!
• Sólo probaba mi nueva cuenta de mail
• I quit!
• Renuncio!
• Como en x-files la pelicula
• Como en la pelicula SpiderMan
• No lo entendi
• La foto esta al reves
• Te lo scannee, de nada...
• RE: Porque?
• RE: Que me enviastes?
• RE: Why?
• A mi no me gustan estas cosas

Message: The message is randomly chosen from the following list:

• Como te lo prometi aca te mando el protector de pantalla, no fue fácil pero lo encontre en www.logratis.com, si quere fijate hay un monton mñas que estan bastante buenos, aunque este por ahora es el mejorcito que encontre.  También me baje un monton de mp3 y fondos de pantallas que despues te los paso. Bue te mando un saludo y nos hablamos luego.
• Hi, wazzzzap! Here´s the screensaver, check it out, it´s pretty cool, i´ve downloaded it from www.download.com try it, hit me back.  Bye
• Hola, cómo va todo? Entre al sitio que me sugeristes y esta muy bueno, me baje un monton de fondos de pantallas, mp3 y protectores de pantallas, te mando uno, es el mejor que encontre a ver que te parece. Bue te mando un saludo nos hablamos luego.
• Hi , How do you do? i visited the site you suggested me and it´s pretty cool, i already downloaded a lot of wallpapers, mp3 and screensaver, i send you this screensaver, it´s the best a found i hope you like.  Well i´ll call you later. Bye
• Qué hiciste BOLUDO???
  

Attachment: The attachment is 48,128 bytes, and is randomly chosen from the following list:

• Ahhhhh.jpg <multiple spaces> .pif
• nota.doc <multiple spaces> .pif
• Juan Pablo.jpg <multiple spaces> .pif
• Return Castle Wolfenstein.jpg <multiple spaces> .pif
• Bill Gate$.jpg <multiple spaces> .pif
• Star Wars Episode II.jpg <multiple spaces> .pif
• aviso.doc <multiple spaces> .pif
• Norton AntiBinladen.jpg <multiple spaces> .pif
• tapa.pdf <multiple spaces> .pif
• Bomb.jpg <multiple spaces> .pif
• pamela la mejor.jpg <multiple spaces> .pif
• polvo.gif <multiple spaces> .pif
• mocosoft.jpg <multiple spaces> .pif
• wuzzzzuppp.jpg <multiple spaces> .pif
• Ciron.jpg <multiple spaces> .pif
• Hernan.jpg <multiple spaces> .pif
• Karner.jpg <multiple spaces> .pif
• Carolina.jpg <multiple spaces> .pif
• my dicovery.jpg <multiple spaces> .pif
• Made in Argentina.jpg <multiple spaces> .pif
• Microsoft ColdMail.jpg <multiple spaces> .pif
• Asi perdi me trabajo.jpg <multiple spaces> .pif
• god vs evil.jpg <multiple spaces> .pif
• chiste.doc <multiple spaces> .pif
• the perfect woman.jpg <multiple spaces> .pif
• La mujer perfecta.jpg <multiple spaces> .pif
• Que feo.jpg <multiple spaces> .pif
• horrible.jpg <multiple spaces> .pif
• powerpuff girls.jpg <multiple spaces> .pif

NOTE: The <multiple spaces> in the file name can be up to 200 spaces. This is done to deceive you into thinking that the file is a graphic.

The worm exploits a vulnerability in Microsoft Outlook and Outlook Express to try to execute itself when you open or preview the message. Information and a patch for the vulnerability can be found at: http://www.microsoft.com/technet/security/bulletin/MS01-020.asp.

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

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

1. Update the virus definitions.
2. Do one of the following:
   • Windows 95/98/Me: Restart the computer in Safe mode.
   • Windows NT/2000/XP: End the Trojan process.
3. Run a full system scan and delete all the files detected as W32.HLLW.Daboom@mm.
4. Reverse the changes that the Trojan made to the registry.
   

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

1. Updating 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: 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 the Virus Definitions (LiveUpdate).
• Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). 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 the Virus Definitions (Intelligent Updater).
  
  The 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. Restarting the computer in Safe mode or ending the Trojan process

Windows 95/98/Me
Restart the computer in Safe mode. All the Windows 32-bit operating systems, except for Windows NT, can be restarted in Safe mode. For instructions on how to do this, read the document, "How to start the computer in Safe Mode."

Windows NT/2000/XP
To end the Trojan process:
1. Press Ctrl+Alt+Delete once.
2. Click Task Manager.
3. Click the Processes tab.
4. Double-click the Image Name column header to alphabetically sort the processes.
5. Scroll through the list and look for Systray32.exe.
6. If you find the file, click it, and then click End Process.
7. Exit the Task Manager.
   

3. Scanning for and deleting the infected files

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 any files are detected as infected with W32.HLLW.Daboom@mm, click Delete.

4. Reversing the changes made to the registry

CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. Read the document, "How to make a backup of the Windows registry," for instructions.

1. Click Start, and then click Run. (The Run dialog box appears.)
2. Type regedit
   
   Then click OK. (The Registry Editor opens.)
   
3. Navigate to the key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, delete the value:
   
   ActiveDesktop    %system%systray32.exe
   
5. Exit the Registry Editor.