W32.Keco@mm

SUMMARY

W32.Keco@mm is a mass-mailing worm that spreads using its own SMTP engine. It emails itself to all email addresses it finds on the infected computer. The subject and attachment of the email will vary. The attachment will have a .zip file extension.

Note: The worm executable has an MD5 hash value of 0x45B142C3D545323D7A49E7A6CA88AF4C.

Protection

• Virus Definitions (LiveUpdate™ Weekly) March 8, 2004
• Virus Definitions (Intelligent Updater) March 8, 2004

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: Low
• Large Scale E-mailing: Mails itself to all the addresses it finds on a compromised computer.
• Causes System Instability: If the mail cannot be sent, the worm continues to sequentially open ports, which could freeze a system.

Distribution

• Distribution Level: High
• Subject of Email: Varies. See "Technical Details" for a list.
• Name of Attachment: Varies. See "Technical Details" for a list. The file arrives as a zip file.
• Size of Attachment: 24,186 byte zip file
• Ports: Sequentially polls TCP ports starting at port 1025. TCP 6667.

TECHNICAL DETAILS

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

1. Copies itself as %System%WinShellb.exe.
   
   

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   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. Modifies the value:
   
   "(Default)" = "Shell=Explorer.exe WinShellb.exe"
   
   in the registry key:
   
   HKey_Local_MachineSoftwareMicrosoftWindowsNTCurrentVersion
   Winlogon
   
   
3. Modifies the following line of the [boot] section of the System.ini file:
   
   Shell="Explorer.exe WinShellb.exe."  
   
   This action ensures that the worm runs when Windows is started.
   
   
4. Creates a mutex named "COKE_DESTROYS_YOUR_BRAIN_5," so that only one instance of the worm can run at a time.
   
   
5. Displays the following message box:
   
   
   
   
   
6. Creates a file, C:coke.txt, which contains rude messages to other worm writers.
   
   
7. Copies itself to the %System% folder as one of the following:
   
   • [1]eCard
   • [0]eCard
   • Document
   • YourFile
   • Your Doc
   • Textfile
   • Profiles
   • Tmp Docu
   • ThisFile
   • YourText
   • 1 Update
   • 3 Update
   • UrDetail
   • NewEmail
   • YourMail
   • TheEmail
   • tmpEMail
   • tmpTexts
   • tmpFiles
   • tmpLogin
   • tmpInfo0
   • tmpInfo1
   • tmpPics0
   • Picture0
   • Pictures
   • Images00
   • Images04
   • MyImages
   • My Image
   • FileInfo
   • InfoFile
   • NewsFile
   • FileNews
   • FileTest
   • FileText
   • Testthis
   • BetaFile
   • TestTest
   • ItsATest
   • Test Pic
   • Pic Test
   • YourTest
   • JPG Test
   • Application
   • Applications
   • Details
   • Your_Details
   • My_Details
   • Your_Profile
   • Your_eCard
   • A_eCard
   • eCard
   • eCard_30042
   • eCard_30259
   • eCard_20349
   • Music
   • MusicPlayer
   • WinZipper
   • ZipFile
   • ZippedFiles
   • ZipDoc
   • ZippedDocs
   • ZippedTexts
   • ZippedPictures
   • RaredDocs
   • RaredPictures
   • RaredTexts
   • RaredDocuments
   • Image
   • IMG_094385
   • IMG_234502
   • IMG_358996
   • IMG_567567
   • IMG_804325
   • IMG_2318975
   • IMG_2186395
   • IMG_2194864
   • IMG_0345486
   • IMG_2384063
   • IMG_34534953
   • IMG_2349
   • Jpeg_file
   • ZippedJpeg
   • Zipped
   • RarFile
   • Rared
   • RaredJpeg
   • RaredMusic
   • MusicRar
   • Your_Application
   • Your_Numbers
   • Your_Login
   • Your_SignIn
   • Your_CardNumber
   • Your_Info
   • Info
   • My_Info
   • Info_Your
   • PornFile
   • PornZip
   • ZippedPorn
   • RarPorn
   • RaredPorn
   • Porn
   • PornPic
   • PictureFile
   • PictureImageFormat
   • LiveDie
   • DieLive
   • Live
   • Life
   • Death
   • Smoke
   • Weed
   • Cigg
   • WeedSmoke
   • SmokeWeed
   • CiggSmoke
   • SmokeCigg
   • CiggWeed
   • WeedCigg
   • Dare
   • WhoDare
   • DareWho
     
     
     These files will have one of the following extensions:
     
   • .exe
   • .scr
   • .cmd
   • .com
   • .bat
   • .pif
     
     
8. Creates a .zip file using the same names above.
   
   
9. Creates an email message with the following characteristics:
   
   From: <spoofed>
   
   Subject: (May be one of the following)
   • Your details
   • Your File
   • Your document
   • eCard sent to you
   • My File
   • Your picture
   • My picture
   • You got a pic ?
   • You got image ?
   • You got picture?
   • Pic?
   • Image?
   • File?
   • File!
   • Document!
   • The document
   • Yours
   • New document
   • New File
   • Your ZIP
   • My private pics
   • My private files
   • My private images
   • My private documents
   • My private textes
   • the text
   • the poem
   • a Poem
   • a Text
   • a Picture
   • a Image
   • My Text
   • My Poem
   • Did you like my poem?
   • Did you like my text?
   • 2 Poem
   • some text
   • whos picture ?
   • a Joke
   • Image of you
   • Links
   • profile
   • your profile
   • Its me :)
   • Im back :D
   • hello dude
   • whats up?
   • sup ?
   • i got a problem
   • warning, its me
   • warning, im hot
   • s--t man :P
   • haha there you are
   • ive searched for you :D
   • wow, im so cool
   • what you want ?
   • hey, stop buggin me
   • is it just me?
   • great
   • doesnt matter to me
   • which u want?
   • gr8 :)
   • hahahahahahaha :D
   • are you jesus? ;D
   • she said what i was supposed to think :P
   • Cute, Boring, Love.
   • cute boring love :P
   • its whats its all about
   • i like apple juice
   • coke just rules done you think ?
   • i want to trademark
   • i want to own you
   • i want you
   • i want to have you
   • dont you longing for purity ?
   • dont you ever gets so sick of territories ?
   • i am naked
   • man im nude
   • dude, im nude
   • what are you so scared of ?
   • sick of spam? so am i :/
   • s--t s--t s--t
   • do you trust me?
   • do i trust you?
   • do you know me?
   • do i know you?
   • i eat glass :D
   • i can walk on the water
   • this is so sick man :D
   • check it out, its sick :D
   • WOW, powerlevel up :D
   • wow hahaha
   • wow, if this aint pron, then i dont know what it is
   • i made a mistake :(
   • is this a mistake ?
   • do you have a mistake ?
   • i made a mistake
   • are you intrested in making movies?
   • making movies ?
   • getting money?
   • i love money
   • do you love money?
   • i got a picture of you and me
   • i got a picture of you
   • i got a picture of me
   • you got a picture of us
   • you got a picture of me
   • you got a picture ?
   • i hate to be singel
   • i hate to not be lesbian
   • i hate to be gay
   • i hate to be a homosexual
   • i am a lesbian
   • i hate fags
   • are you a f-g?
   • is this right mail?
   • is this james?
   • is this kirk?
   • is this kurt?
   • is this rutger?
   • is this stefan?
   • is this stephen?
   • is this mary?
   • is this julie?
   • is this ?
   • is ?
   • want to listen on some music?
   • oh yea, thats how i like it
   • how i like it
   • oh yea
   • im afraid
   • im not afraid
   • im afraid of dieing
   • im afraid of begin ignore
   • im afraid of feeling
   • im not afraid of trying
   • do you got msn?
   • do you got icq?
   • do you got aim?
   • do you got mail? :D
   • where is the sky?
   • i am hiding
   • noone knows, just u and i
   • just u and i
   • U and i
   • U + I
   • I + U
   • i see everything :D
   • Best i am
   • I am Best
   • Am best I
   • Am i Best
   • Best Am I
   • i Best Am
   • blah blah blah
   • words, i hate words
   • w0rd
     
     And, which may be preceded with Re:, re:, Fwd:, or FWD:
     
     Attachment:
     One of the aforementioned .zip files.
     
     
10. Sequentially opens TCP ports, starting with port 1025.
    
    
11. Attempts to connect to predefined IRC servers using IRC port 6667. The user names are random, but always end with domain, @foo.bar.

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. Disable System Restore (Windows Me/XP).
2. Update the virus definitions.
3. Run a full system scan and delete all the files detected as W32.Keco@mm.
4. Edit the System.ini file.
5. Delete the value from the registry.

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

1. Disabling 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"

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

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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. 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: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

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.Keco@mm, click Delete.
   
   
4. Editing the System.ini file.
   
   If you are running Windows 95/98/Me, follow these steps:

1. The function you perform depends on your operating system:
   • Windows 95/98: Go to step B.
   • Windows Me: If you are running Windows Me, the Windows Me file-protection process may have made a backup copy of the System.ini file that you need to edit. If this backup copy exists, it will be in the C:WindowsRecent folder. Symantec recommends that you delete this file before continuing with the steps in this section. To do this:
     1. Start Windows Explorer.
     2. Browse to and select the C:WindowsRecent folder.
     3. In the right pane, select the Win.ini file and delete it. The System.ini file will be regenerated when you save your changes to it in step F.
        
        
2. Click Start, and then click Run.
3. Type the following, and then click OK.
   
   edit c:windowssystem.ini
   
   (The MS-DOS Editor opens.)
   
   NOTE: If Windows is installed in a different location, make the appropriate path substitution.
   
   
4. In the [boot] section of the file, look for a line similar to:
   
   shell = Explorer.exe WinShellb.exe
   
   
5. If this line exists, delete everything to the right of Explorer.exe.
   
   When you are done, it should look like:
   
   shell = Explorer.exe
   
   
6. Click File, and then click Save.
7. Click File, and then click Exit.
   
   

4. Deleting the value from the registry

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WARNING: 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 keys only. Read the document, "How to make a backup of the Windows registry," for instructions.

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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_MachineSoftwareMicrosoftWindowsNTCurrentVersion
   Winlogon
   
   
4. In the right pane, change the value to:
   
   "(Default)" = "Shell=Explorer.exe"
   
   
5. Exit the Registry Editor.