BKDR_BIFROSE.DQI

April 18, 2013
 ALIASES:

VirTool:Win32/DelfInject.gen!AC (Microsoft); Suspicious.SillyFDC (Symantec); Trojan.1 (Sunbelt); Trojan horse IRC/BackDoor.SdBot4.KIY (AVG)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • 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.

  TECHNICAL DETAILS

File Size:

859,648 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

18 Apr 2013

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 creates the following folders:

  • %Program Files%\CodeCoul
  • %Start Menu%\Programs\Code couleurs
  • %System%\win32spn

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.. %System% is the Windows system folder, which is usually C:\Windows\System32.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
win32spn = "%System%\win32spn\win32spn.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
win32spn = "%System%\win32spn\win32spn.exe"

Other System Modifications

This backdoor deletes the following files:

  • %Program Files%\CodeCoul\Uninstal.exe
  • %Program Files%\CodeCoul\CodeCouleur.exe
  • %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).. %Windows% is the Windows folder, which is usually C:\Windows.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
Code couleurs

HKEY_CURRENT_USER\SOFTWARE\Victime

HKEY_CURRENT_USER\SOFTWARE\SpyNet

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Code couleurs
DisplayName = "Code couleurs"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Code couleurs
UninstallString = "%Program Files%\CodeCoul\Uninstal.exe"

HKEY_CURRENT_USER\Software\Victime
FileNameAtual = "%Windows%\win32spn.exe"

HKEY_CURRENT_USER\Software\Victime
FirstExecution = "01/04/2013 -- 22:12"

HKEY_CURRENT_USER\Software\Victime
ByPersist = "%System%\win32spn\win32spn.exewin32spnwin32spn"

HKEY_CURRENT_USER\Software\Victime
FileName = "Dlzcs1JtFiFdifAOxfQDRfRiNiFT7mo7Zl38Ut5K+w0rvBR2WaYlwwA"

HKEY_CURRENT_USER\Software\SpyNet
StartPersist = "{random characters}"

HKEY_CURRENT_USER\Software\Victime
HKLM = "39GIGWLLNML"

HKEY_CURRENT_USER\Software\Victime
HKCU = "39GIGWLLNML"

Dropping Routine

This backdoor drops the following files:

  • %Windows%\Code_Couleur.exe
  • %Windows%\win32spn.exe
  • %Program Files%\CodeCoul\Uninstal.$$A
  • %Program Files%\CodeCoul\CodeCouleur.$$A
  • %Start Menu%\Programs\Code couleurs\Désinstaller Code couleurs.lnk
  • %Start Menu%\Programs\Code couleurs\CodeCouleur.exe.lnk
  • %System%\win32spn\logs.dat
  • %System%\win32spn\plugin.dat
  • %System%\win32spn\win32spn.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.. %System% is the Windows system folder, which is usually C:\Windows\System32.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

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\Windows\CurrentVersion\Uninstall
    • Code couleurs
  • In HKEY_CURRENT_USER\SOFTWARE
    • Victime
  • In HKEY_CURRENT_USER\SOFTWARE
    • SpyNet

Step 4

Delete this registry value

[ 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\Windows\CurrentVersion\Run
    • win32spn = "%System%\win32spn\win32spn.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • win32spn = "%System%\win32spn\win32spn.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Code couleurs
    • DisplayName = "Code couleurs"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Code couleurs
    • UninstallString = "%Program Files%\CodeCoul\Uninstal.exe"
  • In HKEY_CURRENT_USER\Software\Victime
    • FileNameAtual = "%Windows%\win32spn.exe"
  • In HKEY_CURRENT_USER\Software\Victime
    • FirstExecution = "01/04/2013 -- 22:12"
  • In HKEY_CURRENT_USER\Software\Victime
    • ByPersist = "%System%\win32spn\win32spn.exewin32spnwin32spn"
  • In HKEY_CURRENT_USER\Software\Victime
    • FileName = "Dlzcs1JtFiFdifAOxfQDRfRiNiFT7mo7Zl38Ut5K+w0rvBR2WaYlwwA"
  • In HKEY_CURRENT_USER\Software\SpyNet
    • StartPersist = "{random characters}"
  • In HKEY_CURRENT_USER\Software\Victime
    • HKLM = "39GIGWLLNML"
  • In HKEY_CURRENT_USER\Software\Victime
    • HKCU = "39GIGWLLNML"

Step 5

Search and delete these components

[ Learn More ]
There may be some components that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %Windows%\Code_Couleur.exe
  • %Windows%\win32spn.exe
  • %Program Files%\CodeCoul\Uninstal.A
  • %Program Files%\CodeCoul\CodeCouleur.A
  • %Start Menu%\Programs\Code couleurs\Désinstaller Code couleurs.lnk
  • %Start Menu%\Programs\Code couleurs\CodeCouleur.exe.lnk
  • %System%\win32spn\logs.dat
  • %System%\win32spn\plugin.dat
  • %System%\win32spn\win32spn.exe
A
  • %Program Files%\CodeCoul\CodeCouleur.A
  • %Start Menu%\Programs\Code couleurs\Désinstaller Code couleurs.lnk
  • %Start Menu%\Programs\Code couleurs\CodeCouleur.exe.lnk
  • %System%\win32spn\logs.dat
  • %System%\win32spn\plugin.dat
  • %System%\win32spn\win32spn.exe
    •
  • In the Look In drop-down list, select My Computer then press Enter.
  • Once located, select the file then press SHIFT+DELETE to delete it.
  • Repeat the said steps for all files listed.

    • • For Windows Vista and Windows 7 users:

    1. Click Start>Computer.
    2. In the Search input box, type:
      • %Windows%\Code_Couleur.exe
      • %Windows%\win32spn.exe
      • %Program Files%\CodeCoul\Uninstal.A
      • %Program Files%\CodeCoul\CodeCouleur.A
      • %Start Menu%\Programs\Code couleurs\Désinstaller Code couleurs.lnk
      • %Start Menu%\Programs\Code couleurs\CodeCouleur.exe.lnk
      • %System%\win32spn\logs.dat
      • %System%\win32spn\plugin.dat
      • %System%\win32spn\win32spn.exe
    3. Once located, select the file then press SHIFT+DELETE to delete it.
    4. Repeat the said steps for all files listed.
      *Note: Read the following Microsoft page if these steps do not work on Windows 7.

    Step 6

    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%\CodeCoul
    • %Start Menu%\Programs\Code couleurs
    • %System%\win32spn

    Step 7

    Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_BIFROSE.DQI. 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.

    Step 8

    Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

    • %Program Files%\CodeCoul\Uninstal.exe
    • %Program Files%\CodeCoul\CodeCouleur.exe
    • %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log


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