WORM_RBOT.VF

Malware type: Worm

Aliases: Backdoor.Win32.Rbot.bch (Kaspersky), W32/Sdbot.worm (McAfee), W32.Spybot.Worm (Symantec), Worm/SdBot.335832 (Avira), W32/Rbot-FJT (Sophos),

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. It scans network shares on random IP addresses. If it has full access rights to a remote system, it copies itself to a list of shared folders.

On systems with restrictive access rights, it attempts to log on using a list of user names and passwords. It may also gather user names and passwords from the system cache. If it is able to successfully drop a copy of itself, it attempts to use the Schedule service to automatically execute itself.

This worm exploits the following known Windows vulnerabilities to propagate across the network:

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

For detailed information about these vulnerabilities, refer to the following Microsoft pages:

This worm also has backdoor functionalities and operates as an IRC bot. It comes with a built-in Internet Relay Chat (IRC) client engine, which enables it to connect to an IRC channel and wait for commands from a malicious user. It processes the commands on the local machine giving remote users virtual control over the infected system.

This worm also steals the Windows Product ID and the CD keys of certain game applications.

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

For additional information about this threat, see:

Description created: Oct. 27, 2004 4:00:45 PM GMT -0800


TECHNICAL DETAILS


Size of malware: 102,400 Bytes

Initial samples received on: Oct 28, 2004

Details:

Installation and Autostart Technique

Upon execution, this worm drops a copy of itself as VARPC32.EXE in the Windows system folder.

(Note: 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.)

It then creates the following registry entries so that it executes every time Windows starts:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\OLE
Microsoft Visual Studio VSA = "VARPC32.EXE"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
CurrentVersion\Run
Microsoft Visual Studio VSA = "VARPC32.EXE"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
CurrentVersion\RunServices
Microsoft Visual Studio VSA = "VARPC32.EXE"

Exploits

This worm exploits the following known Windows vulnerabilities to propagate across the network:

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

For detailed information about these vulnerabilities, refer to the following Microsoft pages:

Network Propagation

This worm spreads via network shares. It scans network shares on random IP addresses. If it has full access rights to a remote system, it copies itself to the following shared folders:

  • Admin$\System32
  • C$\Windows\System32
  • C$\WINNT\System32

On systems with restrictive access rights, it attempts to log on using a list of user names and passwords. It may also gather user names and passwords from the system cache. If it is able to successfully drop a copy of itself, it attempts to use the Schedule service to automatically execute itself.

Backdoor Capabilities

This worm also has backdoor capabilities and operates as an IRC bot. It connects to a remote IRC server and joins a specific IRC channel, where it receives commands from a remote malicious user.

Some of these commands are as follows:

  • Delete, list or rename files
  • Download files
  • Execute file
  • Find files
  • Flush DNS or ARP cache
  • Get CD keys of games and Microsoft Product ID
  • Get network information
  • Get system information
  • Launch ICMP, PING, SYN, TCP and UDP flood attacks
  • Log keystrokes
  • List and terminate processes
  • List and terminate threads
  • Log off, reboot or shut down system
  • Start packet sniffer
  • Remote command shell
  • Scan vulnerable systems
  • Secure system against common means of infection
  • Send email
  • Send file via IRC DCC
  • Start HTTP, SOCKS, FTP server
  • Take screen or webcam capture
  • TCP port redirect
  • Update malware file
  • Upload file to FTP
  • Use Microsoft Net commands
  • Use mIRC commands
  • Visit URL

Information Theft

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

  • Battlefield 1942
  • Battlefield 1942 (Road To Rome)
  • Battlefield 1942 (Secret Weapons of WWII)
  • Battlefield Vietnam
  • Black and White
  • Chrome
  • Command and Conquer: Generals
  • Command and Conquer: Generals (Zero Hour)
  • Command and Conquer: Red Alert
  • Command and Conquer: Red Alert 2
  • Command and Conquer: Tiberian Sun
  • Counter-Strike (Retail)
  • FIFA 2002
  • FIFA 2003
  • Freedom Force
  • Global Operations
  • Gunman Chronicles
  • Half-Life
  • Hidden & Dangerous 2
  • IGI 2: Covert Strike
  • Industry Giant 2
  • James Bond 007: Nightfire
  • Legends of Might and Magic
  • Medal of Honor: Allied Assault
  • Medal of Honor: Allied Assault: Breakthrough
  • Medal of Honor: Allied Assault: Spearhead
  • Nascar Racing 2002
  • Nascar Racing 2003
  • Need For Speed Hot Pursuit 2
  • Need For Speed: Underground
  • Neverwinter Nights
  • Neverwinter Nights (Hordes of the Underdark)
  • Neverwinter Nights (Shadows of Undrentide)
  • NHL 2002
  • NHL 2003
  • NOX
  • Rainbow Six III RavenShield
  • Shogun: Total War: Warlord Edition
  • Soldier of Fortune II - Double Helix
  • Soldiers Of Anarchy
  • The Gladiators
  • Unreal Tournament 2003
  • Unreal Tournament 2004



Analysis by: Jameson Ong

Revision History:

First pattern file version: 7.537.00
First pattern file release date: Oct 13, 2010

SOLUTION


Minimum scan engine version needed: 6.810

Pattern file needed: 7.537.00

Pattern release date: Oct 13, 2010


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

This procedure terminates the running malware process.

  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 process:
    VARPC32.EXE
  3. Select the malware process, then press either the End Task or the End Process button, depending on the version of Windows on your system.
  4. To check if the malware process has been terminated, close Task Manager, and then open it again.
  5. 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:
    Microsoft Visual Studio VSA= �VARPC32.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 Visual Studio VSA= �VARPC32.EXE�
  6. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>OLE
  7. In the right panel, locate and delete the entry:
    Microsoft Visual Studio VSA= �VARPC32.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 in safe mode.

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_RBOT.VF. 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 on certain platforms. Download and install the critical patches from the following links:




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