Content

Exploit-MSExcel.n

Type
Trojan
SubType
Exploit
Discovery Date
07/12/2007
Length
Varies
Minimum DAT
5073 (07/12/2007)
Updated DAT
6555 (12/09/2011)
Minimum Engine
5.4.00
Description Added
07/12/2007
Description Modified
05/02/2011 12:56 AM (PT)
Risk Assessment
Corporate User
Low
Home User
Low

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Characteristics

Exploit-MSExcel.n is a detection for malicious XLS documents targeting Microsoft Excel vulnerabilities.

Such exploit files could be executed by opening specially crafted malicious Excel files, and the end result could vary between memory corruption to the silent installation of any number of viruses, trojans, and potentially unwanted programs.

When executed, the Trojan drops a file into the following location:

  • %Temp%\D.tmp

Upon execution, the Trojan tries to connect to the following site:

  • www.webse[Removed]ynssl.com

The following registry key has been added.

  • HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components\{C6020422-2143-4CAF-91BB-46425236F5A8}

The following registry value has been added.

  • [HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components\{C6020422-2143-4CAF-91BB-46425236F5A8}\]
    “StubPath” = “%Windir%\system32\iexplorer.exe”

The above mentioned registry ensures that, the Trojan registers with the compromised system and execute itself upon every boot.

McAfee has observed variants of Exploit-MSExcel.n which attempt to exploit the vulnerability described in CVE-2007-1756. Additional information on this vulnerability can be found at:“CVE-2007-1756“

Symptoms

Presence of above mentioned registry keys and activities.

Method of Infection

This threat exploits a Microsoft Excel vulnerability. It may be mass spammed as e-mail attachments and requires the user to open the Excel document and click on a hyperlink embedded in an Excel worksheet.

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.

Variants

Variants

    N/A

All Information

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.

File Information

  • MD5  -  6332B0F7C40D4FDCD8D145F40323948C
  • SHA  - 12C9AD8D7C1CDBD4F167F56FB28C7E99EAEBFDD4

Aliases

  • Kaspersky - Trojan-Dropper.MSExcel.Agent.bk
  • Symantec  - Trojan.Mdropper
  • Ikarus       - Exploit.Win32.CVE-2009
  • Microsoft - Exploit:Win32/CVE-2009-3129.B

Characteristics

Characteristics -

Exploit-MSExcel.n is a detection for malicious XLS documents targeting Microsoft Excel vulnerabilities.

Such exploit files could be executed by opening specially crafted malicious Excel files, and the end result could vary between memory corruption to the silent installation of any number of viruses, trojans, and potentially unwanted programs.

When executed, the Trojan drops a file into the following location:

  • %Temp%\D.tmp

Upon execution, the Trojan tries to connect to the following site:

  • www.webse[Removed]ynssl.com

The following registry key has been added.

  • HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components\{C6020422-2143-4CAF-91BB-46425236F5A8}

The following registry value has been added.

  • [HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components\{C6020422-2143-4CAF-91BB-46425236F5A8}\]
    “StubPath” = “%Windir%\system32\iexplorer.exe”

The above mentioned registry ensures that, the Trojan registers with the compromised system and execute itself upon every boot.

McAfee has observed variants of Exploit-MSExcel.n which attempt to exploit the vulnerability described in CVE-2007-1756. Additional information on this vulnerability can be found at:“CVE-2007-1756“

Symptoms

Symptoms -

Presence of above mentioned registry keys and activities.

Method of Infection

Method of Infection -

This threat exploits a Microsoft Excel vulnerability. It may be mass spammed as e-mail attachments and requires the user to open the Excel document and click on a hyperlink embedded in an Excel worksheet.

Removal -

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.

Variants

Variants -

    N/A