Analysis by: Merianne Polintan
ALIASES:

Mal/Banload-AB (Sophos), W32/Banload.RXB!tr.dldr (Fortinet), Trojan.Win32.ChePro (Ikarus), a variant of Win32/TrojanDownloader.Banload.RXB trojan (NOD32)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  TECHNICAL DETAILS

File Size: 668,672 bytes
File Type: , DLL
Memory Resident: Yes
Initial Samples Received Date: 10 May 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 files:

  • %User Profile%\Recent\{File Name}.cpl.lnk

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
RecentDocs\.cpl
0 = "{File Name}.cpl.lnk"

HKEY_CURRENT_USER\Software\WinRar\
ArcHistory
0 = "%Application Data%\tmp.zip"

Download Routine

This Trojan accesses websites to download the following files:

  • http://www.{BLOCKED}e.fr/joomlaB/logs/tmp/user/cache/teste.zip

It saves the files it downloads using the following names:

  • %Application Data%\tmp.zip
  • %Application Data%\goto.txt
  • %Application Data%\libmysql.dll
  • %Application Data%\retorno.exe
  • %Temporary Internet Files%\teste.zip

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.. %Temporary Internet Files% is the Temporary Internet Files folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temporary Internet Files on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Microsoft\Windows\Temporary Internet Files on Windows Vista and 7.)

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.918.05
FIRST VSAPI PATTERN DATE: 10 May 2013
VSAPI OPR PATTERN File: 9.919.00
VSAPI OPR PATTERN Date: 11 May 2013

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

Scan your computer with your Trend Micro product and note files detected as TROJ_BANLOAD.HWM

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete the files detected as TROJ_BANLOAD.HWM

*Note: Some component files may be 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.

To stop the malware/grayware from running when certain files are opened:

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Right-click Start then click Search....
  2. In the Named input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.

For Windows Vista and Windows 7:

  1. Click Start>Computer.
  2. In the Search Computer input box, type the name of the file detected earlier, and press Enter.
  3. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: Read the following Microsoft page if these steps do not work on Windows 7.

Step 5

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\CurrentVersion\Explorer\RecentDocs\.cpl
    • 0 = "{File Name}.cpl.lnk"
  • In HKEY_CURRENT_USER\Software\WinRar\ArcHistory
    • 0 = "%Application Data%\tmp.zip"

Step 6

Search and delete these files

[ Learn More ]
There may be some 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.
  • %Application Data%\tmp.zip
  • %Application Data%\goto.txt
  • %Application Data%\libmysql.dll
  • %Application Data%\retorno.exe
  • %Temporary Internet Files%\teste.zip

Step 7

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