TROJ_BSCOPE.ZVF

 Modified by: David John Agni

 ALIASES:

Worm.Win32.Taterf.b (v) (Sunbelt)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

It deletes registry entries, causing some applications and programs to not function properly.

  TECHNICAL DETAILS

File Size:

155,648 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

28 May 2012

Arrival Details

This Trojan 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 Trojan drops the following file(s)/component(s):

  • %User Temp%\A1.zip
  • %User Temp%\B1.zip
  • %User Temp%\Iig.dll
  • %User Temp%\tEuH.dll
  • %System%\eHagA
  • %System%\Softwdm.dll
  • %System%\wshtcpWD.dll
  • %System%\drivers\377ff95a.sys

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Autostart Technique

This Trojan registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects
{6535B502-80F2-4CCB-8E5A-5A91ABA63744} =

It 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\377ff95a
DisplayName = "377ff95a"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\377ff95a
ImagePath = "\??\%System%\drivers\377ff95a.sys"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
IEHlprObj.IEHlprObj

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
IEHlprObj.IEHlprObj.1

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6535B502-80F2-4CCB-8E5A-5A91ABA63744}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{6535B508-80F2-4CCB-8E5A-5A91ABA63744}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\HOOK_ID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\SYS_DLL

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6535B502-80F2-4CCB-8E5A-5A91ABA63744}\InprocServer32
(Default) = "%System%\Softwdm.dll"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6535B502-80F2-4CCB-8E5A-5A91ABA63744}\ProgID
(Default) = IEHlprObj.IEHlprObj.1

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{6535B501-80F2-4CCB-8E5A-5A91ABA63744}
(Default) = "IIEHlprObj"

It deletes the following registry entries:

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

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://get.{BLOCKED}z.com/xx

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

9.147.01

FIRST VSAPI PATTERN DATE:

28 May 2012

VSAPI OPR PATTERN File:

9.148.00

VSAPI OPR PATTERN Date:

29 May 2012

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

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\Classes
    • IEHlprObj.IEHlprObj
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes
    • IEHlprObj.IEHlprObj.1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
    • {6535B502-80F2-4CCB-8E5A-5A91ABA63744}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
    • {6535B508-80F2-4CCB-8E5A-5A91ABA63744}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
    • HOOK_ID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
    • SYS_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%\drivers\25e3765b.sys
  • %System%\Softwdm.dll
  • %User Temp%\A1.zip
  • %User Temp%\B1.zip
  • %User Temp%\yquydys.dll
  • %User Temp%\ruu.dll
  • %System%\wshtcpWD.dll
  • %System%\wshtcpip.dll

Step 6

Restore this deleted registry key/value from backup

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

Step 7

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