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BKDR_HUPIGO.AVB

December 11, 2012
 ALIASES:

Trojan:Win32/Delf.EP (Microsoft); Generic PUP.x!bh. (McAfee); Downloader (Symantec); Trojan.Crypt.CFI.Gen (fs) (Sunbelt); Trojan.Generic.2348791 (FSecure)

 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.

It modifies files, disabling programs and applications from properly running.

  TECHNICAL DETAILS

File Size:

792,064 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

08 Dec 2012

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:

  • %Windows%\Driver Cache\bLTbJRygOV.exe
  • %Program Files%\Outlook Express\msoeresgOwfM.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).)

Autostart Technique

This backdoor registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ERFRFSERER\Parameters

Other System Modifications

This backdoor modifies the following files:

  • %Start Menu%\Programs\Internet Explorer.lnk
  • %Start Menu%\Programs\Windows Media Player.lnk
  • %Start Menu%\Programs\Accessories\Notepad.lnk
  • %Start Menu%\Programs\Accessories\Entertainment\Windows Media Player.lnk

(Note: %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.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Directory\shell\open\
command

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Drive\shell\open\
command

HKEY_CLASSES_ROOT\CLSID\{75EA2845-EAD5-486E-A339-59FED49289A6}

HKEY_CLASSES_ROOT\CLSID\{75EA2845-EAD5-486E-A339-59FED49289A6}\
InprocServer32

HKEY_CLASSES_ROOT\PROTOCOLS\Filter\
text/html

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost\
tIwLyLyL

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{75EA2845-EAD5-486E-A339-59FED49289A6}\InprocServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
PROTOCOLS\Filter\text/html
CLSID = "{75EA2845-EAD5-486E-A339-59FED49289A6}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
tIwLyLyL = "ERFRFSERER"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost\
tIwLyLyL
CoInitializeSecurityParam = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ERFRFSERER\Parameters
ServiceDll = "%Windows%\addins\GTGvPbPbPa.dll"

Dropping Routine

This backdoor drops the following files:

  • %System%\HoHagmwBg.dll
  • %Windows%\Media\Windows XP ExclamationLTcKTb.dll
  • %Windows%\Resources\zIRygNVcJR.dll.tmp
  • %Windows%\addins\GTGvPbPbPa.dll.tmp
  • %User Profile%\Quick Launch\Launch Internet Explorer Browser.lnk
  • %Windows%\DelA.bat
  • %User Profile%\NTUSER.DATGOxfP.dat
  • %Program Files%\Internet Explorer\iedwOWfOWeN.dll-temp
  • %Program Files%\Internet Explorer\dQcNyJTdtz.exe
  • %Program Files%\Windows Media Player\dMUdLTtKSa.exe
  • %System%\WfOxgPtf.exe
  • %Program Files%\Windows Media Player\wJvHSePt.exe
  • %Program Files%\Internet Explorer\KyLwtv.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %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).)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

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

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\SYSTEM\CurrentControlSet\Services\ERFRFSERER
    • Parameters
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Directory\shell\open
    • command
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Drive\shell\open
    • command
  • In HKEY_CLASSES_ROOT\CLSID
    • {75EA2845-EAD5-486E-A339-59FED49289A6}
  • In HKEY_CLASSES_ROOT\CLSID\{75EA2845-EAD5-486E-A339-59FED49289A6}
    • InprocServer32
  • In HKEY_CLASSES_ROOT\PROTOCOLS\Filter
    • text/html
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost
    • tIwLyLyL

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\Classes\CLSID\{75EA2845-EAD5-486E-A339-59FED49289A6}\InprocServer32
    • ThreadingModel = "Apartment"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\PROTOCOLS\Filter\text/html
    • CLSID = "{75EA2845-EAD5-486E-A339-59FED49289A6}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost
    • tIwLyLyL = "ERFRFSERER"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost\tIwLyLyL
    • CoInitializeSecurityParam = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ERFRFSERER\Parameters
    • ServiceDll = "%Windows%\addins\GTGvPbPbPa.dll"

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.
  • %System%\HoHagmwBg.dll
  • %Windows%\Media\Windows XP ExclamationLTcKTb.dll
  • %Windows%\Resources\zIRygNVcJR.dll.tmp
  • %Windows%\addins\GTGvPbPbPa.dll.tmp
  • %User Profile%\Quick Launch\Launch Internet Explorer Browser.lnk
  • %Windows%\DelA.bat
  • %User Profile%\NTUSER.DATGOxfP.dat
  • %Program Files%\Internet Explorer\iedwOWfOWeN.dll-temp
  • %Program Files%\Internet Explorer\dQcNyJTdtz.exe
  • %Program Files%\Windows Media Player\dMUdLTtKSa.exe
  • %System%\WfOxgPtf.exe
  • %Program Files%\Windows Media Player\wJvHSePt.exe
  • %Program Files%\Internet Explorer\KyLwtv.exe

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_HUPIGO.AVB. 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 7

Restore deleted/modified files and/or registry entries from backup

*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

    • %Start Menu%\Programs\Internet Explorer.lnk
    • %Start Menu%\Programs\Windows Media Player.lnk
    • %Start Menu%\Programs\Accessories\Notepad.lnk
    • %Start Menu%\Programs\Accessories\Entertainment\Windows Media Player.lnk


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