WORM_SPYBOT.MAR

Malware type: Worm

Aliases: HEUR/Crypted (Avira),

In the wild: Yes

Destructive: No

Language: English

Platform: Windows 95, 98, ME, NT, 2000, XP

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:

High

Distribution potential:

High

Description: 

This memory-resident worm propagates across networks by exploiting the LSASS vulnerability, which is a buffer overrun that allows remote code execution and enables a malicious user to gain full control of an affected system. For more information about the said Windows vulnerability, please refer to the following Microsoft Web page:

It also propagates via network shares by dropping a copy of itself into several shared folders.

This worm opens a random port and operates as an Internet Relay Chat (IRC) bot that connects to an IRC server. It then joins an IRC channel, where it waits for several commands from a malicious user.

It also drop a file detected as TROJ_ROOTKIT.H into the Windows system folder.

For additional information about this threat, see:

Description created: Feb. 21, 2005 5:19:47 PM GMT -0800


TECHNICAL DETAILS


Memory resident:  Yes

Size of malware: 217,088 Bytes

Ports used: Random

Initial samples received on: Feb 15, 2005

Vulnerability used:  (MS04-011) Security Update for Microsoft Windows (835732)

Related toTROJ_ROOTKIT.H

Payload 1: Compromises system security

Trigger condition 1: Upon execution

Payload 2: Steals system information

Trigger condition 1: Upon execution

Details:

Installation and Autostart Techniques

Upon execution, this memory-resident worm drops the following files in the Windows system folder.

  • HPWSNNSBC.EXE � a copy of itself
  • MSDIRECTX.SYS - detected as TROJ_ROOTKIT.H, which hides a copy of this worm from users

To enable its automatic execution at every system startup, it creates the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Win Drivers SSL32 = "hpwsnnsbc.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunServices
Win Drivers SSL32 = "hpwsnnsbc.exe"

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\RunServices
Win Drivers SSL32 = "hpwsnnsbc.exe"

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
Win Drivers SSL32 = "hpwsnnsbc.exe"

Other Registry Modifications

As part of its installation routine, this worm also adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\Ole
Win Drivers SSL32 = "hpwsnnsbc.exe"

HKEY_CURRENT_USER\System\CurrentControlSet\
Control\Lsa
Win Drivers SSL32 = "hpwsnnsbc.exe"

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Control\Lsa
Win Drivers SSL32 = "hpwsnnsbc.exe"

Moreover, it creates the following registry subkeys on NT-based systems (Windows NT, 2000, and XP):

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Enum\Root\LEGACY_MSDIRECTX

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\msdirectx

It changes certain registry entries, which make an affected system susceptible to malicious routines. The modified entries are as follows:

HKEY_LOCAL_MACHINE\Software\Microsoft\Ole
EnableDCOM = "N"

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Control\Lsa
restrictanonymous = "dword:00000001"

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SharedAccess
Start = "dword:00000004"

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\wuauserv

Network Propagation and Exploit

This worm spreads via network shares. It tries to drop a copy of itself into the following shared folders:

  • ADMIN$
  • ADMIN$\System32
  • C$\Windows\System32
  • C$\WINNT\system32
  • D$
  • E$
  • IPC$

This worm also utilizes the LSASS vulnerability, which is a buffer overrun that allows remote code execution and enables a malicious user to gain full control of an affected system. For more information about the said Windows vulnerability, please refer to the following Microsoft Web page:

Backdoor Capabilities

This worm also has backdoor capabilities.

It opens a random port and operates as an Internet Relay Chat (IRC) bot that connects to an IRC server. It then joins an IRC channel, where it waits for several commands from a malicious user.

It has the following capabilities:

  • Disable and enable DCOM and network shares
  • Download, execute, and open files
  • List and terminate threads
  • Monitor channels
  • Obtain email messages and other system information
  • Perform basic IRC commands
  • Redirect TCP stream
  • Restrict and unrestrict access to IPC$
  • Send UDP packets to a remote user
  • Scan ports
  • Update itself

Analysis By: Elda Viray Dimakiling


SOLUTION


Minimum scan engine version needed: 6.810

Pattern file needed: 2.409.01

Pattern release date: Feb 15, 2005


Important note: The "Minimum scan engine" refers to the earliest Trend Micro scan engine version guaranteed to detect this threat. However, Trend Micro strongly recommends that you update to the latest version in order to get comprehensive protection. Download the latest scan engine here.

Solution:

Restarting in Safe Mode

On Windows 95

  1. Restart your computer.
  2. Press F8 at the Starting Windows 95 message.
  3. Choose Safe Mode from the Windows 95 Startup Menu then press Enter.

On Windows 98 and ME

  1. Restart your computer.
  2. Press the CTRL key until the startup menu appears.
  3. Choose the Safe Mode option then press Enter.

On Windows NT (VGA mode)

  1. Click Start>Settings>Control Panel.
  2. Double-click the System icon.
  3. Click the Startup/Shutdown tab.
  4. Set the Show List field to 10 seconds and click OK to save this change.
  5. Shut down and restart your computer.
  6. Select VGA mode from the startup menu.

On Windows 2000

  1. Restart your computer.
  2. Press the F8 key, when you see the Starting Windows bar at the bottom of the screen.
  3. Choose the Safe Mode option from the Windows Advanced Options Menu then press Enter.

On Windows XP

  1. Restart your computer.
  2. Press F8 after the Power-On Self Test (POST) is done. If the Windows Advanced Options Menu does not appear, try restarting and then pressing F8 several times after the POST screen.
  3. Choose the Safe Mode option from the Windows Advanced Options Menu then press Enter.

Note: After performing all the solutions for the removal of this malware, please restart your system normally, and run your Trend Micro antivirus product.

Identifying the Malware Program

To remove this malware, first identify the malware program.

  1. Scan your system with your Trend Micro antivirus product.
  2. NOTE all files detected as WORM_SPYBOT.MAR.

Trend Micro customers need to download the latest pattern file before scanning their system. Other users can use Housecall, Trend Micro�s online virus scanner.

Terminating the Malware Program

This procedure terminates the running malware process. You will need the name(s) of the file(s) detected earlier.

  1. Open Windows Task Manager.
    On Windows 95, 98, and ME, press
    CTRL%20ALT%20DELETE
    On Windows NT, 2000, and XP, press
    CTRL%20SHIFT%20ESC, then click the Processes tab.
  2. In the list of running programs*, locate the malware file(s) detected earlier.
  3. Select one of the detected files, then press either the End Task or the End Process button, depending on the version of Windows on your system.
  4. Do the same for all detected malware files in the list of running processes.
  5. To check if the malware process has been terminated, close Task Manager, and then open it again.
  6. Close Task Manager.

*NOTE: On systems running Windows 95, 98, and ME, Windows Task Manager may not show certain processes. You can use a third party process viewer such as Process Explorer to terminate the malware process. Otherwise, continue with the next procedure, noting additional instructions.

Editing the Registry

This malware modifies the system's registry. Users affected by this malware may need to modify or delete specific registry keys or entries. For detailed information regarding registry editing, please refer to the following articles from Microsoft:

  1. HOW TO: Backup, Edit, and Restore the Registry in Windows 95, Windows 98, and Windows ME
  2. HOW TO: Backup, Edit, and Restore the Registry in Windows NT 4.0
  3. HOW TO: Backup, Edit, and Restore the Registry in Windows 2000
  4. HOW TO: Back Up, Edit, and Restore the Registry in Windows XP

Removing Autostart Entries from the Registry

Removing autostart entries from the registry prevents the malware from executing at startup.

  1. Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
  2. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>Software>Microsoft>
    Windows>CurrentVersion>Run
  3. In the right panel, locate and delete the entry:
    Win Drivers SSL32 = "hpwsnnsbc.exe"
  4. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>Software>Microsoft>
    Windows>CurrentVersion>RunServices
  5. In the right panel, locate and delete the entry:
    Win Drivers SSL32 = "hpwsnnsbc.exe"
  6. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>
    Windows>CurrentVersion>Run
  7. In the right panel, locate and delete the entry:
    Win Drivers SSL32 = "hpwsnnsbc.exe"
  8. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>
    Windows>CurrentVersion>RunServices
  9. In the right panel, locate and delete the entry:
    Win Drivers SSL32 = "hpwsnnsbc.exe"

NOTE: If you were not able to terminate the malware process as described in the previous procedure, restart your system.

Removing Other Entries from the Registry

  1. Still in the Registry Editor, double-click the following in the left panel:
    HKEY_LOCAL_MACHINE>System>CurrentControlSet>
    Control>Lsa
  2. In the right panel, locate and delete the entry:
    Win Drivers SSL32 = "hpwsnnsbc.exe"
  3. In the left panel, double-click the following:
    HKEY_CURRENT_USER>System>CurrentControlSet>
    Control>Lsa
  4. In the right panel, locate and delete the entry:
    Win Drivers SSL32 = "hpwsnnsbc.exe"
  5. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>Ole
  6. In the right panel, locate and delete the entry:
    Win Drivers SSL32 = "hpwsnnsbc.exe"
  7. In the left panel, locate and delete the following subkeys:
    • HKEY_LOCAL_MACHINE>System>CurrentControlSet>Enum>Root
      LEGACY_MSDIRECTX
    • HKEY_LOCAL_MACHINE>System>CurrentControlSet>Services
      msdirectx
  8. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>Software>Microsoft>Ole
  9. In the right panel, locate and change the entry or entries into the following default value:
    EnableDCOM = "Y"
  10. Close Registry Editor.

Restoring EnableDCOM and RestrictAnonymous Registry Entries

This malware modifies EnableDCOM and RestrictAnonymous registry entries to a certain value. To know more about restoring these registries to their original values, please refer to these articles:

  1. COM security frequently asked questions
  2. How to disable DCOM support in Windows
  3. How to Use the RestrictAnonymous Registry Value in Windows 2000
  4. The "RestrictAnonymous" Registry Value May Break the Trust to a Windows 2000 Domain

Additional Windows ME/XP Cleaning Instructions

Users running Windows ME and XP must disable System Restore to allow full scanning of infected systems.

Users running other Windows versions can proceed with the succeeding procedure set(s).

Running Trend Micro Antivirus

Scan your system with Trend Micro antivirus and delete all files detected as WORM_SPYBOT.MAR and TROJ_ROOTKIT.H. To do this, Trend Micro customers must download the latest pattern file and scan their system. Other Internet users can use HouseCall, Trend Micro�s online virus scanner.

(NOTE: To completely remove TROJ_ROOTKIT.H from your system, please refer to its manual clean instruction page.)




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