TROJ_BUKC.B
Windows 2000, XP, Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted: No
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 executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.
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. It attempts to steal information, such as user names and passwords, used when logging into certain banking or finance-related websites.
TECHNICAL DETAILS
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%\Tcp_IP.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
(Default) = %Windows%\Tcp_IP.exe
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Tcp_IP
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = 0
Dropping Routine
This Trojan drops the following files:
- %System%\drivers\regtoro.sys - detected as TSPY_BANKER.ROZ
(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 executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.
Information Theft
This Trojan 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:
- Banrisul - Internet Explorer
- Portal Internet Banrisul
- [bb.com.br] - Mozilla Firefox
- http://www.bb.com.br/portalbb/home
- http://www.bradesco.com.br/
- http://www.itaupersonnalite.com.br/index.jsp
- http://www.itauprivatebank.com.br/privatebank/default.aspx
- http://www.santander.com.br
- htt ://www.serasa.com.br/
- http://www.serasaexperian.com.br/
- https://internetbanking.caixa.gov.br/SIIBC/index.processa
- https://internetbanking.caixa.gov.br/SIIBC/siwinCtrl
- https://www.caixa.gov.br/_newredirect/barra/r_IBC.asp
- https://www.cetelem.com.br/wps/portal/cetelem/normal/NL/login
- https://www2.bancobrasil.com.br/aapf/login.jsp?aapf.IDH=sim&perfil=1
- https://wwwss.bradesco.com.br/scripts/ib2k1.dll/LOGIN?AGN=
The spoofed login overlaps the legitimate login area of the website, thus tricking the user into thinking that it is part of the IE window. The spoofed login page is located in a fixed area of the legitimate website. The said routine tricks the user into giving out sensitive account-related information. It then logs keystrokes entered by the user in the user name and password fields of the spoofed login page.
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.
It attempts to steal information from the following banks and/or other financial institutions:
- Banco Itau
- Banco Santander
- Banco do Brasil
- Banrisul
- Bradesco
- Caixa
- Cetelem
- Serasa
Stolen Information
This Trojan sends the gathered information via HTTP POST to the following URL:
- http://members.{BLOCKED}ania.co.uk/mundodasmaquinas/Sabado.php
Drop Points
This Trojan sends the information it gathers to the following email addresses:
- {BLOCKED}rtadorasiqueira@gmail.com
- {BLOCKED}ortadoranortesul@gmail.com
Variant Information
This Trojan has the following MD5 hashes:
- 17bdd4c3a38765d950318a7650f53d82
It has the following SHA1 hashes:
- 43b2af108122c342a072010cadedd032b1eece23
SOLUTION
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
Remove malware files dropped/downloaded by TROJ_BUKC.B
- TSPY_BANKER.ROZ
Step 3
Restart in Safe Mode
Step 4
Delete this registry value
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
- (Default) = %Windows%\Tcp_IP.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
- EnableLUA = 0
Step 5
Delete this registry key
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_CURRENT_USER
- Tcp_IP
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_BUKC.B. 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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