WORM_RBOT.ABG

Malware type: Worm

Aliases: Backdoor.Win32.Rbot.gen (Kaspersky), W32/Sdbot.worm.gen.by (McAfee), Backdoor.Sdbot (Symantec), Worm/Rbot.210944 (Avira), W32/Rbot-Fam (Sophos), Backdoor:Win32/Rbot (Microsoft)

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 worm spreads via network shares, and takes advantage of the following Windows vulnerabilities to propagate across networks:

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

For more information about these Windows vulnerabilities, please refer to the following Microsoft Web pages:

This worm attempts to log on to systems using a list of passwords hardcoded in its body. It then drops a copy of itself in all accessed machines.

This worm has backdoor capabilities and may execute commands issued by a remote user, which include launching various methods of distributed denial of service (DDoS) attacks against certain Web sites. It also steals the CD keys and even game applications and software products.

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

For additional information about this threat, see:

Description created: Nov. 16, 2004 1:08:51 PM GMT -0800
Description updated: Nov. 16, 2004 4:01:31 PM GMT -0800


TECHNICAL DETAILS


Size of malware: Varies

Initial samples received on: Nov 16, 2004

Payload 1: Compromises system security

Details:

Installation and Autostart

Upon execution, this memory-resident worm drops a copy of itself as JAVAVM.EXE in the Windows system folder. This file has read-only, hidden and system file attributes. It then proceeds to delete itself.

It may add the following registry keys to enable its automatic execution upon Windows startup:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
MS Java virtual machine = �javavm.exe�

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
MS Java virtual machine = �javavm.exe�

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\RunServices
MS Java virtual machine = �javavm.exe�

Exploits

This worm takes advantage of certain vulnerabilities. It exploit the following Windows vulnerabilities to propagate across networks:

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

The RPC/DCOM exploit is a vulnerability that allows an attacker to gain full access and execute any code on a target machine by sending a malformed packet to the DCOM service. It uses the RPC TCP port 135. More information on this vulnerability from the following Web page:

The IIS/WebDAV exploit enables arbitrary codes to execute on the WebDAV server by also sending a malformed request packet. This exploit is a service related to the HTTP on port 80. More information about this vulnerability is found in the following URL:

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.

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

Network Propagation

This worm spreads via network shares. It uses NetBEUI functions to get available lists of user names and passwords. It then searches for and lists down the following shared folders, where it drops a copy of itself using the gathered information:

  • ADMIN$
  • ADMIN$\system32
  • C$
  • C$\Windows\system32
  • C$\WINNT\system32
  • D$
  • PRINT$

This worm also attempts to access systems with weak passwords, and drop a copy of itself on successfully accessed machines. It uses the following hardcoded list of common passwords to gain access to target systems:

If successfully dropped, the worm copy is remotely executed as a service.

Backdoor Capabilities

This worm connects to port 6667 (a normal mIRC port) and joins a specific channel where it listens for commands from the remote malicious user.

Some of these commands are as follows:

Information Theft

This worm also steals the Windows Product ID, as well as the CD keys of the following game applications:

Other Details

This worm is written and compiled in Visual C%20%20, a high-level programming language.




Analysis by: Elmer M. Ubalde

Revision History:

First pattern file version: 2.250.09
First pattern file release date: Nov 16, 2004

SOLUTION


Minimum scan engine version needed: 6.810

Pattern file needed: 5.665.00

Pattern release date: Nov 20, 2008


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_RBOT.ABG.

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.

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:
    MS Java virtual machine = �javavm.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:
    MS Java virtual machine = �javavm.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:
    MS Java virtual machine = �javavm.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

Running Trend Micro Antivirus

Scan your system with Trend Micro antivirus and delete all files detected as WORM_RBOT.ABG. 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.

Applying Patches

This malware exploits known vulnerabilities in Windows. Download and install the fix patches from the following Web pages:

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


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