WORM_SDBOT.BGF

Malware type: Worm

Aliases: Backdoor.Win32.IRCBot.bq (Kaspersky), W32/Sdbot.worm.gen (McAfee), W32.Randex (Symantec), Worm/SdBot.35145 (Avira), W32/Sdbot-Fam (Sophos),

In the wild: No

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 worm propagates via network shares. It creates a helper batch file to do this process. After execution, this batch is automatically deleted.

It drops a copy of itself in a list of accessible network shares. If the said shares are password-protected, this worm uses a list of user names and passwords as its login credential to gain access.

It attempts to connect to an Internet Relay Chat (IRC) server and listen for commands from a malicious user. It has the capability to perform a list of commands locally on affected machines.

For additional information about this threat, see:

Description created: Jun. 16, 2005 10:46:10 AM GMT -0800


TECHNICAL DETAILS


File type: EXE

Memory resident:  Yes

Size of malware: 35,153 Bytes (compressed)

Initial samples received on: Jun 14, 2005

Compression type: FSG

Details:

Installation and Autostart

Upon execution, this worm drops a copy of itself using a random file name in the Windows system folder. It creates the following autostart entries to ensure its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
%Varies% = �%Malware%�

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\RunServices
%Varies% = �%Malware%�

It registers itself as a service by adding the following registry entry:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
%Varies% = �%Malware%�

Note: %Varies% refers to the following strings, which are hardcoded in its body:

  • disgx
  • Swdaswdw
  • yoink

%Varies% may also contain other varied strings.

Note: %Malware% refers to the following strings, which are hardcoded in its body:

  • didesgx.exe
  • dywwif.exe
  • qdwwdtx.exe

%Malware% may also contain other varied strings.

Network Propagation

This worm propagates via network shares. It creates a helper batch file to do this process. After execution, this batch is automatically deleted.

It drops a copy of itself in the following network shares:

  • ADMIN$\system32
  • C$\Documents and Settings\All Users\Documents
  • C$\shared
  • C$\Windows\system32
  • C$\WINNT\system32
  • IPC$

If the said shares are password-protected, this worm uses the following user names and passwords to gain access:

  • 123qaz
  • 123qwe
  • 123qwe123
  • admin
  • administrador
  • administrateur
  • administrator
  • billgate
  • billgates
  • freddy
  • freddy
  • fuckyou
  • internet
  • intranet
  • motdepass
  • nokia
  • pass1234
  • passwd
  • qazwsx
  • qwe123
  • qweasd
  • qweasdzxc
  • staff
  • student
  • student1
  • teacher
  • turnip
  • user1
  • zaq123
  • zaqxsw
  • zxc123
  • zxcvbnm

Backdoor Capabilities

This worm attempts to connect to an Internet Relay Chat (IRC) server and listen for commands from a malicious user. It has the capability to do the following actions locally on affected machines:

  • Connect to a particular IRC server
  • Download a file from the Internet
  • Uninstall itself
  • Download an updated copy of itself

Platform

This worm runs on Windows 95, 98, ME, NT, 2000, and XP.

Analysis By: Jayronn Christian S. Bucu

Revision History:

First pattern file version: 2.686.02
First pattern file release date: Jun 14, 2005

SOLUTION


Minimum scan engine version needed: 7.500

Pattern file needed: 3.632.04

Pattern release date: Aug 2, 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:

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_SDBOT.BGF.

Trend Micro customers need to download the latest pattern file before scanning their system. Other users can use Housecall, Trend Micro�s free 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. If you were not able to terminate the malware process as described in the previous procedure, restart your system.

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: Back Up, Edit, and Restore the Registry in Windows XP
  4. HOW TO: Backup, Edit, and Restore the Registry in Windows 2000

Removing Autostart Entries from the Registry

Removing autostart entries from the registry prevents the malware from executing at startup. In this procedure, you will need the name(s) of the file(s) detected earlier.

  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 or entries whose data value is the malware path and file name of the file(s) detected earlier.
  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 or entries whose data value is the malware path and file name of the file(s) detected earlier.
  6. Again 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 or entries whose data value is the malware path and file name of the file(s) detected earlier.
  8. Close Registry Editor.

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 sets.

Running Trend Micro Antivirus

Scan your system with Trend Micro antivirus and delete all files detected as WORM_SDBOT.BGF. 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 free online virus scanner.




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