ALIASES:

PWS-Banker.gen.i (McAfee); Trojan.Win32.BHO.e (Kaspersky); Trojan horse Generic2.AWD.dropper (AVG)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • 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.

  TECHNICAL DETAILS

File Size: 427,008 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 04 Apr 2013

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 copies of itself into the affected system:

  • %Windows%\SoftUpdate.exe
  • %System%\sncool.scr

(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %System% is the Windows system folder, which is usually C:\Windows\System32.)

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 keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\explorer\
Browser Helper Objects\{E730189A-9973-4121-B046-AD1C161EC3AF}

Other System Modifications

This Trojan deletes the following files:

  • %System Root%\WIN_PO~1.BAT

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It adds the following registry keys:

HKEY_CLASSES_ROOT\CLSID\{E730189A-9973-4121-B046-AD1C161EC3AF}

HKEY_CLASSES_ROOT\CLSID\{E730189A-9973-4121-B046-AD1C161EC3AF}\
InprocServer32

HKEY_CLASSES_ROOT\37211.HahaPP

HKEY_CLASSES_ROOT\37211.HahaPP\Clsid

HKEY_CLASSES_ROOT\CLSID\{E730189A-9973-4121-B046-AD1C161EC3AF}\
ProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
htmlfile\shell\htmlfile\
shell\opennew\command

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
htmlfile\shell\SOFTWARE\
Classes\htmlfile\shell\
open\command

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
htmlfile\shell\htmlfile\
shell\opennew\command\
CLSID\{0002DF01-0000-0000-C000-000000000046}\LocalServer32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
htmlfile\shell\SOFTWARE\
Classes\htmlfile\shell\
open\command\SOFTWARE\
Classes\htmlfile\shell\
opennew\command

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E730189A-9973-4121-B046-AD1C161EC3AF}\InprocServer32
ThreadingModel = "Apartment"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Enable Browser Extensions = "yes"

Dropping Routine

This Trojan drops the following files:

  • %System%\37211.dll
  • %System Root%\win_pop_flag_1__1.bat

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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

Close all opened browser windows

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_CLASSES_ROOT\CLSID
    • {E730189A-9973-4121-B046-AD1C161EC3AF}
  • In HKEY_CLASSES_ROOT\CLSID\{E730189A-9973-4121-B046-AD1C161EC3AF}
    • InprocServer32
  • In HKEY_CLASSES_ROOT
    • 37211.HahaPP
  • In HKEY_CLASSES_ROOT\37211.HahaPP
    • Clsid
  • In HKEY_CLASSES_ROOT\CLSID\{E730189A-9973-4121-B046-AD1C161EC3AF}
    • ProgID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\htmlfile\shell\htmlfile\shell\opennew
    • command
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\htmlfile\shell\SOFTWARE\Classes\htmlfile\shell\open
    • command
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\htmlfile\shell\htmlfile\shell\opennew\command\CLSID\{0002DF01-0000-0000-C000-000000000046}
    • LocalServer32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\htmlfile\shell\SOFTWARE\Classes\htmlfile\shell\open\SOFTWARE\Classes\htmlfile\shell\opennew
    • command

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\{E730189A-9973-4121-B046-AD1C161EC3AF}\InprocServer32
    • ThreadingModel = "Apartment"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Enable Browser Extensions = "yes"

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%\37211.dll
  • %System Root%\win_pop_flag_1__1.bat

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_BHO.BB. 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 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.

  • %System Root%\WIN_PO~1.BAT


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