WORM_SDBOT.AEL

Malware type: Worm

Aliases: Backdoor.Win32.IRCBot.bl (Kaspersky), W32/Sdbot.worm.gen.t (McAfee), Trojan.Dropper (Symantec), Worm/SdBot.109167 (Avira), Troj/Multidr-AZ (Sophos),

In the wild: Yes

Destructive: No

Language: English

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

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:

High

Distribution potential:

High

Description: 

This memory-resident worm arrives and propagates through network shares. Upon execution, it drops the following files into the Windows system folder:

  • CACASP.EXE
  • CVASDDQ.EXE
  • DQDDSS.EXE

It may attempt to use its own list of user names and passwords to gain access and further propagate onto other shared folders.

It also has backdoor capabilities. It comes with a built-in Internet Relay Chat (IRC) bot which allows it to connect to an IRC server. It then waits for commands from a remote user. Once connected, the remote user gains virtual control of the affected system.

It runs on Windows 98, ME, NT, 2000, and XP.

For additional information about this threat, see:

Description created: Nov. 27, 2004 2:15:13 AM GMT -0800


TECHNICAL DETAILS


Size of malware: 109,167 Bytes

Initial samples received on: Nov 27, 2004

Payload 1: Compromises system security

Payload 2: Performs DoS attacks

Details:

Installation and Autostart Techniques

This memory-resident worm arrives and propagates through network shares. Upon execution, it drops the following files into the Windows system folder:

  • CACASP.EXE
  • CVASDDQ.EXE
  • DQDDSS.EXE

It creates the following registry entries to ensure it automatically executes during every Windows startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
CurrentVersion\Run
DSAcass = "%System%\CACASP.EXE"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
CurrentVersion\Run
ddqdsxnfqs = "DQDDSS.EXE"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
CurrentVersion\RunServices
ddqdsxnfqs = "DQDDSS.EXE"

HKEY_CURRENT_USER\Software\Microsoft\Windows\
CurrentVersion\Run
ddqdsxnfqs = "DQDDSS.EXE"

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 95, 98 and ME, C:\WINNT\System32 on Windows NT and 2000, and C:\Windows\System32 on Windows XP.)

Propagation via Network Shares

This worm propagates through network shares. It generates IP addresses, and attempts to drop a copy of itself to a target address� default share. If the shared folder is password protected, it uses a the following pre-defined list of user names and passwords:

  • access
  • accounting
  • accounts
  • admin
  • administrateur
  • administrator
  • backup
  • barbara
  • blank
  • bruce
  • capitol
  • changeme
  • cisco
  • compaq
  • control
  • database
  • databasepass
  • databasepassword
  • db1234
  • dbpass
  • dbpassword
  • default
  • domain
  • domainpass
  • domainpassword
  • exchange
  • exchnge
  • freddy
  • guest
  • headoffice
  • heaven
  • homeuser
  • internet
  • intranet
  • katie
  • login
  • loginpass
  • nokia
  • oeminstall
  • oemuser
  • office
  • orange
  • pass1234
  • passwd
  • password
  • password1
  • siemens
  • sqlpass
  • staff
  • student
  • student1
  • teacher
  • technical
  • turnip
  • user1
  • userpassword
  • win2000
  • win2k
  • win98
  • windows
  • winnt
  • winpass
  • winxp
  • yellow

Once login is successful, it drops and executes a copy of itself in the following shared folders:

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

Backdoor Routine

This worm also has backdoor capabilities. It comes with a built-in Internet Relay Chat (IRC) bot that allows it to connect to a specific IRC server. It then waits for commands from a remote user. Once connected, the remote user gains virtual control of the affected system. The remote user can then execute the following denial of service (DoS) attacks against a target site:

  • HTTP flood attack
  • ICMP flood attack
  • SYN flood attack
  • UDP flood attack

The remote user can also download and execute files onto the affected system.






Analysis by: Daniel M. Biado


SOLUTION


Minimum scan engine version needed: 6.810

Pattern file needed: 2.266.01

Pattern release date: Nov 27, 2004


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.AEL.

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 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 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.

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:
    DSAcass = "%System%\CACASP.EXE" HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>
    Windows>CurrentVersion>Run
  4. In the right panel, locate and delete the entry:
    ddqdsxnfqs = "DQDDSS.EXE"
  5. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>
    Windows>CurrentVersion>RunServices
  6. In the right panel, locate and delete the entry:
    ddqdsxnfqs = "DQDDSS.EXE"
  7. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>
    Windows>CurrentVersion>Run
  8. In the right panel, locate and delete the entry:
    ddqdsxnfqs = "DQDDSS.EXE"
    (Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 95, 98 and ME, C:\WINNT\System32 on Windows NT and 2000, and C:\Windows\System32 on Windows XP.)
  9. Close Registry Editor.

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

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.AEL. 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.


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