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WORM_SDBOT.DAE

Malware type: Worm

Aliases: W32/Sdbot.worm.gen.bs (McAfee), W32.Spybot.Worm (Symantec), TR/Crypt.D.131 (Avira), W32/Sdbot-Fam (Sophos),

In the wild: Yes

Destructive: No

Language: English

Platform: Windows NT, 2000, XP

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:

 High

Distribution potential:

 High

Infection Channel 1 : Propagates via software vulnerabilities

Description: 

This worm spreads by exploiting the following vulnerabilities:

  • RPCSS Buffer Overrun vulnerability
  • Workstation Service vulnerability
  • ASN.1 Library Bitstring Heap Overflow vulnerability

More information about the said vulnerabilities can be found in the following pages:

This worm has backdoor capabilities. It opens a random port, connects to a certain Internet Relay Chat (IRC) server, and joins a certain channel upon connection. It then listens for commands coming from a remote user, which it executes on the affected computer.

It also terminates several processes related to security applications.

For additional information about this threat, see:

Description created: Apr. 12, 2006 5:06:36 PM GMT -0800

Minimum scan engine version needed: 7.500

Pattern file needed: 3.254.03

Pattern release date: Mar 9, 2006


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:

Terminating the Malware Program

Since this malware terminates the Windows Task Manager, it is necessary to use third party process viewers such as Process Explorer.

If the process you are looking for is not in the list displayed by Process Explorer, proceed to the succeeding solution set.

  1. Download Process Explorer.
  2. Extract the contents of the compressed (ZIP) file to a location of your choice.
  3. Execute Process Explorer by double-clicking procexp.exe.
  4. In the Process Explorer window, locate the process:
    MSWINDTC.EXE
  5. Right-click the malware process, then click Kill Process Tree.
  6. Close Process Explorer.
*NOTE: On computers running all Windows platforms, if the process you are looking for is not in the list displayed by Process Explorer, continue with the next solution procedure, noting additional instructions. If the malware process is in the list displayed by Process Explorer, but you are unable to terminate it, restart your computer in safe mode.

Editing the Registry

This malware modifies the computer'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 NT 4.0
  2. HOW TO: Backup, Edit, and Restore the Registry in Windows 2000
  3. HOW TO: Back Up, Edit, and Restore the Registry in Windows XP and Server 2003

Removing Autostart Entries and Other Added Entries from the Registry

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

If the registry entries below are not found, the malware may not have executed as of detection. If so, proceed to the succeeding solution set.

  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 msdt service = "mswindtc.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 msdt service = "mswindtc.exe"
  6. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Ole
  7. In the right panel, locate and delete the entry:
    win msdt service = "mswindtc.exe"
  8. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SYSTEM>CurrentControlSet>
    Control>Lsa
  9. In the right panel, locate and delete the entry:
    win msdt service = "mswindtc.exe"
  10. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>
    Windows>CurrentVersion>Run
  11. In the right panel, locate and delete the entry:
    win msdt service = "mswindtc.exe"
  12. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>
    Windows>CurrentVersion>RunServices
  13. In the right panel, locate and delete the entry:
    win msdt service = "mswindtc.exe"
  14. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>OLE
  15. In the right panel, locate and delete the entry:
    win msdt service = "mswindtc.exe"
  16. In the left panel, double-click the following:
    HKEY_CURRENT_USER>SYSTEM>CurrentControlSet>
    Control>Lsa
  17. In the right panel, locate and delete the entry:
    win msdt service = "mswindtc.exe"

Restoring Modified Registry Entries

  1. Still in the Registry Editor, in the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SYSTEM>CurrentControlSet>
    Services>SharedAccess
  2. In the right panel, locate the entry:
    Start = "dword:00000004"
  3. Right-click on this entry, select "Modify" from the context menu, and enter the value:
    Start = "dword:00000003"
  4. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SYSTEM>CurrentControlSet>
    Services>wuauserv
  5. In the right panel, locate the entry:
    Start = "dword:00000004"
  6. Right-click on this entry, select "Modify" from the context menu, and enter the value:
    Start = "dword:00000002"

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

To restore this entry to its default value, please perform the following instructions:

  1. Still in the Registry Editor, in the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Ole
  2. In the right panel, locate the entry:
    EnableDCOM = "N"
  3. Right-click on this registry entry and choose Modify. Change the value of this entry to:
    EnableDCOM = "Y"
  4. Close Registry Editor.

Important Windows XP Cleaning Instructions

Users running Windows XP must disable System Restore to allow full scanning of infected computers.

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

Running Trend Micro Antivirus

If you are currently running in safe mode, please restart your computer normally before performing the following solution.

Scan your computer with Trend Micro antivirus and delete files detected as WORM_SDBOT.DAE. To do this, Trend Micro customers must download the latest virus pattern file and scan their computer. Other Internet users can use HouseCall, the Trend Micro online virus scanner.

Applying Patches

Download and install the following patches supplied by Microsoft:

Refrain from using this product until the appropriate patch has been installed. Trend Micro advises users to download critical patches upon release by vendors.




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