TSPY_BANCOS.BVL

October 09, 2012
 Analysis by: Jasen Sumalapao
 ALIASES:

Trojan-Banker.Win32.Banbra.atfl (Kaspersky), Troj/Bancos-BOI (Sophos), Trojan.Banker.Delf.AAEW (FSecure), Trojan.Win32.Generic!BT (Sunbelt), TR/Banker.Banbra.atfl (Antivir), Trojan.Banker.Delf.AAEW (Bitdefender), W32/Banbra.ATFL!tr (Fortinet), Trojan-Banker.Win32.Banbra (Ikarus), Win32/Spy.Banker.YJS trojan (NOD32)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

This spyware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be manually installed by a user.

It uses common file icons to trick a user into thinking that the files are legitimate.

It attempts to steal sensitive online banking information, such as user names and passwords. This routine risks the exposure of the user's account information, which may then lead to the unauthorized use of the stolen data.

  TECHNICAL DETAILS

File Size:

16472624 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

11 Sep 2012

Payload:

Steals information

Arrival Details

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

It may be manually installed by a user.

Installation

This spyware drops a copy of itself in the following folders using different file names:

  • %System%\GbPlugin-Módulo de Segurança.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It drops the following component file(s):

  • %\Windows%\WD777(1)(incremental number).txt
  • %\Windows%\WLog777.txt

It uses common file icons to trick a user into thinking that the files are legitimate.

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WinAmp = %Windows%\winsync(1).exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WinAmp {incremental number} = %Windows%\winsync(incremental number).exe

Information Theft

This spyware monitors the Internet Explorer (IE) activities of the affected system, specifically the address bar or title bar. It recreates a legitimate website with a spoofed login page if a user visits banking sites with the following strings in the address bar or title bar:

  • http://www.bancodobrasil.com.br
  • http://www.caixa.com.br
  • http://www.caixa.gov.br
  • http://www.itau.com.br
  • https://wwws3.hsbc.com.br

It attempts to steal sensitive online banking information, such as user names and passwords. This routine risks the exposure of the user's account information, which may then lead to the unauthorized use of the stolen data.

Stolen Information

This spyware sends the data it gathers to the following email addresses via SMTP:

  • {BLOCKED}newlife@yahoo.com
  • {BLOCKED}urado2010.2@gmail.com

NOTES:

Upon accessing the target bank Web page, this spyware closes the browser, except if opened in Internet Explorer (IE), and displays the following message:

Consequent access of the target bank web page asks the user to update its browser’s version and also displays the following message:

It poses as a fake application from a legitimate company and also uses a legitimate electronic certificate or digital signature to trick users into thinking they are part of legitimate applications.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

9.388.03

FIRST VSAPI PATTERN DATE:

11 Sep 2012

VSAPI OPR PATTERN File:

9.389.00

VSAPI OPR PATTERN Date:

12 Sep 2012

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

Search and delete these files

[ Learn More ]
There may be some component files 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%\WD777(1)(incremental number).txt
  • %\Windows%\WLog777.txt

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
    • WinAmp = "%Windows%\winsync(1).exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • WinAmp {incremental number} = "%Windows%\winsync(incremental number).exe"

Step 5

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