BackDoor-CVZ

This page shows details and results of our analysis on the malware BackDoor-CVZ

Download Current DAT: 6617

Threat Detail

Malware Type: Trojan

Malware Sub-type: Remote Access

Discovery Date: 2005-12-02

Next Steps:

Overview
Characteristics
Symptoms
Method of Infection
Removal

Overview

This is a trojan detection. Unlike viruses, trojans do not self-replicate. They are spread manually, often under the premise that they are beneficial or wanted. The most common installation methods involve system or security exploitation, and unsuspecting users manually executing unknown programs. Distribution channels include email, malicious or hacked web pages, Internet Relay Chat (IRC), peer-to-peer networks, etc.

Minimum DAT

4642 (2005-12-02)

Updated DAT

4866 (2006-10-04)

Minimum Engine

5.1.00

File Length

Varies

Description Added

2005-12-02

Description Modified

2005-12-12

Malware Proliferation

Characteristics

This detection is for a remote access trojan written in VC++.

Installation

Upon execution, the trojan installs itself into the %ProgramFiles%\Windows Media Player\ directory as svchost.exe.

(Where %Program Files% is the Windows Program Files directory, for example C:\Program Files )

For example:

C:\Program Files\Windows Media Player\svchost.exe

The following Windows Registry key is added to hook system startup:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\ Run
"SKYNET Personal FireWall" = "C:\Program Files\Windows Media Player\svchost.exe"

Remote Access Functionality

Once running on the victim machine, the server component opens a TCP socket accepting commands sent from the client component on port 21111.

The client component offers many functions to the hacker, including:

Executing any command
Search and list files on the victim hard drive(s)
Upload/download/execute files on the victim machine

Symptoms

The following TCP port open: 21111
Existence of the files/Registry keys detailed above

Method of Infection

Trojans do not self-replicate. They are spread manually, often under the premise that the executable is something beneficial. Distribution channels include IRC, peer-to-peer networks, newsgroup postings, email, etc.

This trojan attempts to disables certain personal firewall products when they are installed, by deleting the following Windows Registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\ CurrentVersion\Run\"iDuba Personal FireWall" = "C:\KAVPFW\KAVPFW.EXE"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\ CurrentVersion\Run\"SKYNET Personal FireWall" = "C:\PROGRA~1\SKYNET\FIREWALL\PFW.EXE"

Removal

All Users:

Please use the following instructions for all supported versions of Windows to remove threats and other potential risks:

1.Disable System Restore .

2.Update to current engine and DAT files for detection and removal.

3.Run a complete system scan.

Modifications made to the system Registry and/or INI files for the purposes of hooking system startup, will be successfully removed if cleaning with the recommended engine and DAT combination (or higher).

1. Please go to the Microsoft Recovery Console and restore a clean MBR.

On windows XP:

Insert the Windows XP CD into the CD-ROM drive and restart the computer.
When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
Select the Windows installation that is compromised and provide the administrator password
Issue 'fixmbr' command to restore the Master Boot Record
Follow onscreen instructions
Reset and remove the CD from CD-ROM drive.

On Windows Vista and 7:

Insert the Windows CD into the CD-ROM drive and restart the computer.
Click on "Repair Your Computer"
When the System Recovery Options dialog comes up, choose the Command Prompt.
Issue 'bootrec /fixmbr' command to restore the Master Boot Record
Follow onscreen instructions
Reset and remove the CD from CD-ROM drive.