Analysis by: Roland Marco Dela Paz
ALIASES:

Bck/Bifrost.gen (Panda)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It connects to a website to send and receive information.

It opens a hidden Internet Explorer window.

  TECHNICAL DETAILS

File Size: Varies
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 09 Mar 2012
Payload: Compromises system security, Steals information

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This backdoor drops the following copies of itself into the affected system:

  • %Program Files%\FireFox\mlbc.exe
  • %Program%\NetMeeting\smsti.exe
  • %Windows%\msndsc\server.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

It creates the following folders:

  • %Program Files%\FireFox
  • %Windows%\msndsc

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

It stays memory-resident by injecting codes into the following processes:

  • explorer.exe

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{621DD232-EA95-C8FA-7879-628B07EE0649}
stubpath = %Program Files%\FireFox\mlbc.exe s

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{2899073A-30C2-91DE-1DA0-7B57F30EA25C}
stubpath = %Program%\NetMeeting\smsti.exe s

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{87FD538E-A5AA-4606-ABB7-C880D6EAD404}
stubpath = %Windows%\msndsc\server.exe s

Other System Modifications

This backdoor adds the following registry keys:

HKEY_CURRENT_USER\Software\58fmsf0vs

HKEY_LOCAL_MACHINE\SOFTWARE\58fmsf0vs

HKEY_USERS\.DEFAULT\Software\
58fmsf0vs

HKEY_LOCAL_MACHINE\SOFTWARE\olyrb

HKEY_CURRENT_USER\Software\olyrb

HKEY_USERS\.DEFAULT\Software\
olyrb

Backdoor Routine

This backdoor connects to the following websites to send and receive information:

  • {BLOCKED}on.{BLOCKED}ogdns.com

Other Details

This backdoor opens a hidden Internet Explorer window.

NOTES:
It is capable of executing the following commands:

  • Capture screenshots
  • Log keystrokes
  • Open command shell
  • Manipulate registries
  • Manipulate files
  • Uninstall/update itself
  • List/terminate processes
  • List and manipulate active windows
  • Gather and list system information
  • List local passwords and Internet Explorer AutoComplete Forms

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.836.03
FIRST VSAPI PATTERN DATE: 14 Mar 2012

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  %Program Files%\FireFox
%Windows%\msndsc

Step 4

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {621DD232-EA95-C8FA-7879-628B07EE0649}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {2899073A-30C2-91DE-1DA0-7B57F30EA25C}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {87FD538E-A5AA-4606-ABB7-C880D6EAD404}
  • In HKEY_CURRENT_USER\Software
    • 58fmsf0vs
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • 58fmsf0vs
  • In HKEY_USERS\.DEFAULT\Software
    • 58fmsf0vs
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • olyrb
  • In HKEY_CURRENT_USER\Software
    • olyrb
  • In HKEY_USERS\.DEFAULT\Software
    • olyrb

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_BIFROSE.SV. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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