TROJ_BANKER.XXVN


 ALIASES:

Backdoor.Trojan (Symantec); Trojan horse PSW.Banker6.BUVK (AVG)

 PLATFORM:

Windows

 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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

114,688 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

04 Dec 2014

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 creates the following folders:

  • %Program Files%\Common Files\Plugins

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Autostart Technique

This Trojan 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\V3Manager\Parameters

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
V3Manager = "{random characters}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager
Description = "Safe manager for V3 AntiVirius"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager
DisplayName = "V3 Manager"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager
ErrorControl = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager
Group = "Com Infrastructure"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager
Type = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager
FailureAction = "{random values}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager
ImagePath = "%SystemRoot%\system32\svchost -k V3Manager"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager\Parameters
ServiceDll = "%System%\V3Manager64.dll"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Manager\Parameters
ServiceMain = "WoMain"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DataAccess
xyz = "{malware path and file name}"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = "www.naver.com"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome.)

Dropping Routine

This Trojan drops the following files:

  • %System%\V3Manager64.dll
  • %Program Files%\Common Files\Plugins\index.txt

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}52.109/lite/index.txt

It deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.700

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\SYSTEM\CurrentControlSet\Services\V3Manager
    • Parameters

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 NT\CurrentVersion\SvcHost
    • V3Manager = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager
    • Description = "Safe manager for V3 AntiVirius"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager
    • DisplayName = "V3 Manager"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager
    • ErrorControl = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager
    • Group = "Com Infrastructure"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager
    • ObjectName = "LocalSystem"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager
    • Start = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager
    • Type = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager
    • FailureAction = "{random values}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager
    • ImagePath = "%SystemRoot%\system32\svchost -k V3Manager"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager\Parameters
    • ServiceDll = "%System%\V3Manager64.dll"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Manager\Parameters
    • ServiceMain = "WoMain"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DataAccess
    • xyz = "{malware path and file name}"

Step 5

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • From: Start Page = "www.naver.com"
      To: Start Page = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome""

Step 6

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%\V3Manager64.dll
  • %Program Files%\Common Files\Plugins\index.txt

Step 7

Search and delete this folder

[ 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%\Common Files\Plugins

Step 8

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