TROJ_BUZUS.BBX

May 06, 2013
 Analysis by: Michael Cabel
 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan accesses websites to download files. This action allows this malware to possibly add other malware on the affected computer.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

01 Jul 2009

Installation

This Trojan drops the following copies of itself into the affected system:

  • %System Root%\RECYCLER\{Random SID}\syscr.exe

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

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = %System Root%\RECYCLER\{Random SID}\syscr.exe,explorer.exe,

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Taskman = %System Root%\RECYCLER\{Random SID}\syscr.exe

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\
Windows\CURRENTVERSION\Policies\
SYSTEM
EnableLUA = 0

Download Routine

This Trojan accesses websites to download the following files:

  • %System%\avgnt.exe
  • %System%\PROCESBLUE.EXE
  • %System%\winsys.exe

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

It accesses the following websites to download files:

  • http://www.{BLOCKED}simoveis.com.br/logomarca.jpg
  • http://www.{BLOCKED}moveis.com.br/index_arquivos/logo.jpg
  • http://{BLOCKED}flavim.com/swing/GeraAviso.jpg

  SOLUTION

Minimum Scan Engine:

8.900

VSAPI OPR PATTERN File:

06.238.04

VSAPI OPR PATTERN Date:

01 Jul 2009

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 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_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
    • Shell = %System Root%\RECYCLER\{Random SID}\syscr.exe,explorer.exe,
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • Taskman = %System Root%\RECYCLER\{Random SID}\syscr.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\Windows\CURRENTVERSION\Policies\SYSTEM
    • EnableLUA = 0

Step 4

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\Windows\CurrentVersion\Explorer
    • From: FaultCount = 1
      To: FaultCount = 0
  • In HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\Windows\CurrentVersion\Explorer
    • From: FaultTime = 344bb
      To: FaultTime = 0

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_BUZUS.BBX. 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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