WORM_SPYBOT.EL

Malware type: Worm

Aliases: Backdoor.Win32.Rbot.gen (Kaspersky), W32/Sdbot.worm.gen.i (McAfee), W32.Spybot.Worm (Symantec), TR/Crypt.ULPM.Gen (Avira), Mal/HckPk-A (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

Description: 

This worm propagates via network shares. It uses NetBEUI functions to get available lists of user names and passwords. It then lists down the available network shares and attempts to drop a copy of itself into these shares using the gathered user names and passwords.

It also generates IP addresses and attempts to drop a copy of itself to a target address default shares. It also uses a predefined list of user names and passwords found in its code in order to gain access on target systems.

This worm has backdoor capabilities, and may execute commands coming from a remote malicious user. It is also capable of identifying systems that are vulnerable to the following exploits:

  • Remote Procedure Call (RPC) Distributed Component Object Model (DCOM) vulnerability
  • Buffer Overflow in SQL Server 2000 vulnerability
  • IIS5/WEBDAV buffer overrun vulnerability
  • LSASS vulnerability

More information on these vulnerabilities can be found in the following Microsoft pages:

This worm runs on Windows NT, 2000, and XP.

For additional information about this threat, see:

Description created: Sep. 18, 2004 11:55:51 AM GMT -0800


TECHNICAL DETAILS


Size of malware: 84,480 Bytes (compressed)

Initial samples received on: Sep 13, 2004

Payload 1: Compromises network security

Details:

Installation and Autostart Techniques

This memory-resident worm may arrive via network shares. Upon execution, it drops a copy of itself in the Windows system folder using the following file name:

    xagwxzy.exe

It creates the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
Microsoft Locals466 = "xagwxzy.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Microsoft Locals466 = "xagwxzy.exe"

It also creates the following registry entry in order this worm to not only run at every system startup, but also run as a service process on NT-based Windows (Windows NT, 2000, and XP):

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\RunServices
Microsoft Locals466 = "xagwxzy.exe"

Network Propagation

This worm propagates via network shares. It uses NetBEUI functions to get available lists of user names and passwords. It then lists down the available network shares and attempts to drop a copy of itself into these shares using the gathered user names and passwords. The dropped copy of this worm has the same file name as that of the executed copy.

It also generates IP addresses and attempts to drop a copy of itself to a target address� default shares:

  • Admin$
  • C$
  • Ipc$

Apart from the the gathered user names and passwords, it also uses a predefined list of user names and passwords found in its code.

For every successful drop of the copy of the malware file into a share, the dropped file is remotely executed as a service.

Backdoor Capabilities

This worm also has backdoor capabilities. It acts as a server program controlled by an Internet Relay Chat (IRC) bot. The connection between this server and the IRC bot is done with the following mIRC properties:

  • IRC server: dgt-bots.mine.nu
  • IRC port: 6667

These properties are encrypted in the malware file.

Once connected, this IRC bot is capable of sending commands to the server program. These commands are used to control the target system and the behavior of the bot.

With the IRC console, the bot inputs the commands to the console and waits to receive information from the server.

Exploits

Aside from its backdoor capabilities, this worm can also automatically notify the bot of systems that are vulnerable to certain Windows exploits.

It takes advantage of the Remote Procedure Call (RPC) Distributed Component Object Model (DCOM) vulnerability present on Windows XP systems, which allows an attacker to gain full access and execute any code on a target machine, leaving it compromised.

Read more on this vulnerability from the following link:

It also takes advantage of the Buffer Overflow in SQL Server 2000 vulnerability. More information about this vulnerability from the following link:

This worm also exploits the IIS5/WEBDAV buffer overrun vulnerability affecting Windows NT platforms, which enables arbitrary codes to execute on the server.

The following link offers more information from Microsoft about this vulnerability:

It also takes advantage of the LSASS Vulnerability, which is a buffer overrun vulnerability that allows remote code execution. Once successfully exploited, a remote attacker is able to gain full control of the affected system.

For more information about this vulnerability, refer to the following Microsoft pages:

This worm scans the network for vulnerable systems and notifies the bot with the vulnerable system�s IP address. Using Class B subnet and the infected system�s IP address, it generates random IP addresses and tests it for vulnerability.

Other Details

This worm arrives PE_Patch-compressed.




Analysis by: Ivan Macalintal


SOLUTION


Minimum scan engine version needed: 6.810

Pattern file needed: 2.171.28

Pattern release date: Sep 13, 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_SPYBOT.EL.

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 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.

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:
    Microsoft Locals466 = "xagwxzy.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:
    Microsoft Locals466 = "xagwxzy.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:
    Microsoft Locals466 = "xagwxzy.exe"
  8. 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_SPYBOT.EL. 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.

Applying Patches

This malware exploits known vulnerabilities in Windows. Download and install the fix patch supplied by Microsoft in the following pages:

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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