Discovered: January 07, 2006
Updated: May 17, 2007 10:00:37 PM
Type: Worm
Infection Length: varies
Systems Affected: Windows

W32.Feebs is a detection for a family of mass-mailing worm that also spreads through file-sharing networks and lowers security settings on the compromised computer. The worm may also send confidential information to a remote attacker via FTP.

The worm variant arrives as an email attachment with an .HTA extension. Once the .HTA file is viewed, a malicious JavaScript then drops or downloads a copy of the worm executable.

Antivirus Protection Dates

  • Initial Rapid Release version January 08, 2006
  • Latest Rapid Release version March 23, 2017 revision 037
  • Initial Daily Certified version January 08, 2006
  • Latest Daily Certified version March 23, 2017 revision 041
  • Initial Weekly Certified release date January 11, 2006

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

Writeup By: Kaoru Hayashi

Discovered: January 07, 2006
Updated: May 17, 2007 10:00:37 PM
Type: Worm
Infection Length: varies
Systems Affected: Windows

W32.Feebs is a detection for a family of mass-mailing worm that also spreads through file-sharing networks and lowers security settings on the compromised computer. The worm may also send confidential information to a remote attacker via FTP.

The worm variant arrives as an email attachment with an .HTA extension. Once the .HTA file is viewed, a malicious JavaScript then drops or downloads a copy of the worm executable.

When the .HTA file is viewed, a malicious JavaScript downloads a base-64 encoded file from one or more of the following locations:

  • [http://]blomor.t35.com/[REMOVED]/app.c
  • [http://]boblol.zoo.by/[REMOVED]/ol.txt
  • [http://]doln.1gb.ru/[REMOVED]/staff.txt
  • [http://]duuw.nm.ru/[REMOVED]/ol.txt
  • [http://]fr33.by.ru/[REMOVED]/ol.txt
  • [http://]poolcool.t35.com/[REMOVED]/bl.c
  • [http://]reep.wol.bz/[REMOVED]/ol.txt
  • [http://]roox.biz.ly/[REMOVED]/ol.txt
  • [http://]volum.1gb.ru/[REMOVED]/ol.txt
  • [http://]yorap.1gb.ru/[REMOVED]/hol.txt
  • [http://]ssddsf.coconia.net/[REMOVED]/lol.txt
  • [http://]pogc.wol.bz/[REMOVED]/lol.txt
  • [http://]jppo.t35.com/[REMOVED]/lol.c
  • [http://]jmo31.by.ru/[REMOVED]/big.txt

It then extracts a Windows executable file from the base-64 encoded file and saves it as C:\recycled\userinit.exe.

Once the W32.Feebs variant is executed, it create the following registry entries so that it runs every time Windows starts:
HKEY_CLASSES_ROOT\CLSID\{[RANDOM CLSID]}\InprocServer32\"(default)" = "%System\[PATH TO DLL WORM COMPONENT]"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ShellServiceObjectDelayLoad\"[FILE NAME OF DLL WORM COMPONENT]" = "{[RANDOM CLSID]}"

It then creates the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{CD5AC91B-AE7B-E83A-0C4C-E616075972F3}\"Stubpath" = "C:\Recycled\userinit.exe"
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\"mal" = "[EMAIL ADDRESS OF RECIPIENT]"

The worm variant may send emails to all addresses found on the compromised computer. Following is an example of the email characterstics:

From: [STRING 1] [STRING 2]

Where [STRING 1] is one of the following:
  • protect
  • secur
  • security
  • securmail

and [STRING 2] is one of the following:
  • @hotmail.com
  • @gmail.com
  • @aol.com
  • @msn.com
  • @yahoo.com

Subject: [STRING 1] [STRING 2] [STRING 3]

Where [STRING 1] is one of the following:
  • Secure
  • Protected
  • Encrypted
  • Extended

[STRING 2] is one of the following:
  • Mail
  • E-Mail
  • Message
  • Html

[STRING 3] is one of the following:
  • [BLANK]
  • System
  • Service
  • Service ([DOMAIN])
  • from [DOMAIN] user.

[STRING 4] is one of the following:
  • Thank you
  • Sincerely
  • Best Regards

For example:
Protected Message from Gmail.com user.
Secure Mail Service (HotMail.com)
Encrypted E-mail from Yahoo.com user.

Message:
You have received [STRING 1] [STRING 2] from [DOMAIN] user.
This message is addressed personally for you.

To decrypt your message use the following details:
ID: [RANDOM NUMBERS]
Password: [RANDOM LETTERS]

Keep your password in a safe place and under no circumstances give it to ANYONE.
[STRING 1] [STRING 2] and instruction is attached.
[STRING 4]
[STRING 1] [STRING 2] [STRING 3],

[DOMAIN]

Where [STRING 1] is one of the following:
  • Secure
  • Protected
  • Encrypted
  • Extended

[STRING 2] is one of the following:
  • Mail
  • E-Mail
  • Message
  • Html

[STRING 3] is one of the following:
  • [BLANK]
  • System
  • Service
  • Service ([DOMAIN])
  • from [DOMAIN] user.

[STRING 4] is one of the following:
  • Thank you
  • Sincerely
  • Best Regards

For example:
You have received Encrypted Message from MSN.com user.
This message is addressed personally for you.

To decrypt your message use the following details:
ID: 44321
Password: mxsjstjgd

Keep your password in a safe place and under no circumstances give it to ANYONE.
Encrypted Message and instruction is attached.
Best Regards,
Encrypted E-mail Service,
MSN.com

Attachment:
One of the following:
  • msg.zip
  • message.zip
  • data.zip
  • mail.zip

The attachment contains a copy of the worm as an .hta file with the following name:

[STRING 1] [STRING 2] File.HTA

Where [STRING 1] is one of the following:
  • Secure
  • Protected
  • Encrypted
  • Extended

[STRING 2] is one of the following:
  • Mail
  • E-Mail
  • Message
  • Html

For example:
  • Extended Mail File.HTA
  • Extended E-Mail File.HTA
  • Secure Mail File.HTA
  • Secure E-Mail File.HTA

The worm varian may create the following files:
  • %System%\MS[RANDOM].exe
  • %System%\MS[RANDOM]
  • %System%\MS[RANDOM]32.DLL

The worm variant may load %System%\MS[RANDOM]32.DLL into all active processes and uses rootkit functionalities to hide its files and registry subkeys.

It also creates the following registry entry:
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\"web"

The worm variant may create several registry subkeys containing configuration info, stolen passwords, accounts, and email addresses:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\dat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\cdat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\fdat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\rdat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\sdat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\ldat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\gdat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\pdat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\udat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\idat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\ddat
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\kdat

The worm variant then attempts to disable the Windows Firewall by modifying the following registry entries:
HKEY_CURRENT_USER\Software\Policies\Microsoft\WindowsFirewall\DomainProfile\"EnableFirewall" = "0"
HKEY_CURRENT_USER\Software\Policies\Microsoft\WindowsFirewall\StandardProfile\"EnableFirewall" = "0"
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\"EnableFirewall" = "0"
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\StandardProfile\"EnableFirewall" = "0"

It may search for folders that contain the following strings:
  • downloads
  • share
  • incoming

The worm variant may copy itself to any folders that it finds as the following files:
  • 3dsmax_9_(3D_Studio_Max)_new!_full+crack.zip
  • ACDSee_9_new!_full+crack.zip
  • Adobe_Photoshop_10_(CS3)_new!_full+crack.zip
  • Adobe_Premiere_9_(2.0_pro)_new!_full+crack.zip
  • Ahead_Nero_8_new!_full+crack.zip
  • DivX_7.0_new!_full+crack.zip
  • ICQ_2006_new!_full+crack.zip
  • Internet_Explorer_7_new!_full+crack.zip
  • Kazaa_4_new!_full+crack.zip
  • Longhorn_new!_full+crack.zip
  • Microsoft_Office_2006_new!_full+crack.zip
  • winamp_5.2_new!_full+crack.zip

The .zip file contains a non-malicious text file that matches the name of the .zip file. It is reported that the text file's name does not include the string "_new!_full+crack".

It may delete all the startup registry subkeys associated with these services under the following subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\[SERVICE NAME]

The worm variant may start a local Web server on TCP port 80. When a user connects to the Web server, it loads the .HTA file and also gives a link to offline.zip, which is a zip file containing the worm.

It may then gather sensitive information from the compromised computer by monitoring open windows. This includes monitoring for WebMoney, ICQ, and cryptography key files.

The worm variant may send this information to a remote attacker.

It may lower security settings on the compromised computer by ending security-related programs and by stopping services with names starting with one of the following strings:
  • armor2net
  • armorwall
  • avgcc
  • avp6
  • aws
  • bgnewsui
  • blackd
  • bullguard
  • ca
  • ccapp
  • ccevtmgr
  • ccproxy
  • ccsetmgr
  • dfw
  • dpf
  • fbtray
  • fireballdta
  • FirePM
  • firesvc
  • firewal
  • fsdfwd
  • fw
  • fwsrv
  • goldtach
  • hacker
  • hackereliminator
  • iamapp
  • iamserv
  • internet security
  • ipatrol
  • ipcserver
  • jammer
  • kaspe
  • kavpf
  • keylog
  • keypatrol
  • KmxAgent
  • KmxBiG
  • KmxCfg
  • KmxFile
  • KmxFw
  • KmxIds
  • KmxNdis
  • KmxSbx
  • kpf4gui
  • kpf4ss
  • leviathantrial
  • looknstop
  • mcafeefire
  • mpftray
  • netlimiter
  • npfc
  • npfmsg
  • npfsvice
  • npgui
  • opf
  • opfsvc
  • outpost
  • pavfnsvr
  • pccpfw
  • pcipim
  • pcIPPsC
  • persfw
  • rapapp
  • RapDrv
  • smc
  • sndsrvc
  • spfirewallsvc
  • spfw
  • sppfw
  • sspfwtry2
  • s-wall
  • symlcsvc
  • ton
  • tzpfw
  • umxtray
  • vipnet
  • vsmon
  • xeon
  • xfilter
  • zapro
  • zlclient
  • zonealarm

Recommendations

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.

Writeup By: Kaoru Hayashi

Discovered: January 07, 2006
Updated: May 17, 2007 10:00:37 PM
Type: Worm
Infection Length: varies
Systems Affected: Windows

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.
  5. Restore the Windows Security Center.

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

1. To disable 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:

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

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. To update 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.

    If you use Norton AntiVirus 2006, Symantec AntiVirus Corporate Edition 10.0, or newer products, LiveUpdate definitions are updated daily. These products include newer technology.

    If you use Norton AntiVirus 2005, Symantec AntiVirus Corporate Edition 9.0, or earlier products, LiveUpdate definitions are updated weekly. The exception is major outbreaks, when definitions are updated more often.


  • 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.

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 .

3. To run a full system scan
  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, follow the instructions displayed by your antivirus program.
Important: If you are unable to start your Symantec antivirus product or the product reports that it cannot delete a detected file, you may need to stop the risk from running in order to remove it. To do this, run the scan in Safe mode. For instructions, read the document, How to start the computer in Safe Mode . Once you have restarted in Safe mode, run the scan again.


After the files are deleted, restart the computer in Normal mode and proceed with the next section.

Warning messages may be displayed when the computer is restarted, since the threat may not be fully removed at this point. You can ignore these messages and click OK. These messages will not appear when the computer is restarted after the removal instructions have been fully completed. The messages displayed may be similar to the following:

Title: [FILE PATH]
Message body: Windows cannot find [FILE NAME]. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button, and then click Search.

4. To delete the value from the registry
Important: 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 subkeys only. For instructions refer to the document: How to make a backup of the Windows registry .
  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 and delete the following entries:

    HKEY_CLASSES_ROOT\CLSID\{[RANDOM CLSID]}\InprocServer32\"(default)" = "%System\[PATH TO DLL WORM COMPONENT]"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ShellServiceObjectDelayLoad\"[FILE NAME OF DLL WORM COMPONENT]" = "{[RANDOM CLSID]}"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{CD5AC91B-AE7B-E83A-0C4C-E616075972F3}\"Stubpath" = "C:\Recycled\userinit.exe"
    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\"mal" = "[EMAIL ADDRESS OF RECIPIENT]"

  5. Navigate to and delete the following subkeys:

    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\"web"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\dat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\cdat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\fdat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\rdat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\sdat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\ldat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\gdat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\pdat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\udat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\idat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\ddat
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MS[RANDOM 2 LETTERS]\kdat


  6. Restore the following registry entries to their original values, if required:

    HKEY_CURRENT_USER\Software\Policies\Microsoft\WindowsFirewall\DomainProfile\"EnableFirewall" = "0"
    HKEY_CURRENT_USER\Software\Policies\Microsoft\WindowsFirewall\StandardProfile\"EnableFirewall" = "0"
    HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\"EnableFirewall" = "0"
    HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\StandardProfile\"EnableFirewall" = "0"

  7. Exit the Registry Editor.
5. To restore the Windows Security Center
This risk attempts to disable the features in the Windows Security Center, available in Windows XP Service Pack 2. If you are running Windows XP Service Pack 2 and would like to restore the full functionality of the Windows Security Center, please complete the following steps:

Important:
If your computer is connected to a domain, you may not be able to adjust these settings. If so, contact your network administrator for more information.
  1. Click Start > Control Panel.
  2. Double-click the Security Center.
  3. In the right pane, click Windows Firewall. The Windows Firewall appears.
  4. Select On.
  5. Click OK to close the Windows Firewall.
  6. In the left pane of the Security Center, select Change the way Security Center alerts me.
  7. Click Alert Settings.
  8. Select Alert Settings, Firewall, and Virus Protection.
  9. Click OK
  10. Click Automatic Updates.
  11. Select Automatic.
  12. Click OK.
  13. Exit the Security Center.

Writeup By: Kaoru Hayashi