Analysis by: Jaime Benigno Reyes
ALIASES:

RDN/PWS-Banker!cx (McAfee), Trojan-Downloader.Win32.Banload.cpds (Kaspersky)

 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:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 196,608 bytes
File Type: DLL
Initial Samples Received Date: 18 Nov 2013
Payload: Connects to URLs/IPs, Downloads files

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_CHEPRO.RTF

Installation

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

  • %Application Data%\{malware name}

(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.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
{malware name} = %Application Data%\{malware name}

Download Routine

This Trojan downloads files from the following File Transfer Protocol (FTP) sites:

  • ftp://ftp.{BLOCKED}ece.com.br/radiotx/xlaborsav.mod
  • ftp://ftp.{BLOCKED}ece.com.br/radiotx/xlaborsge.mod
  • ftp://ftp.{BLOCKED}ece.com.br/radiotx/xlaborsrm.mod
  • ftp://ftp.{BLOCKED}ece.com.br/radiotx/xlaborswb.mod

It saves the files it downloads using the following names:

  • %Application Data%\xlaborsav.mod - encrypted
  • %Application Data%\xlaborsge.mod - encrypted
  • %Application Data%\xlaborsrm.mod - encrypted
  • %Application Data%\xlaborswb.mod - encrypted

(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.)

NOTES:

The malware TROJ_CHEPRO.CPL performs the following routines:

  • Revoke specified user's access rights
  • Deny specified user access
  • Replace specified user's access rights on AVAST and AVG software

This malware will also restart the system.

After reboot, its copy located at %Application Data% will run and decrypt the file %Application Data%\xlaborsav.mod. The decrypted file will be renamed to xlaborsav.exe (detected as TSPY_BANCOS.CVH). Finally, it will execute the file xlaborsav.exe.

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.418.05
FIRST VSAPI PATTERN DATE: 18 Nov 2013
VSAPI OPR PATTERN File: 10.419.00
VSAPI OPR PATTERN Date: 19 Nov 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

Remove malware/grayware files that dropped/downloaded TROJ_CHEPRO.CPL

Step 3

Remove the malware/grayware file dropped/downloaded by TROJ_CHEPRO.CPL

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • {malware name} = %Application Data%\{malware name}

Step 5

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%\xlaborsav.mod
  • %Application Data%\xlaborsge.mod
  • %Application Data%\xlaborsrm.mod
  • %Application Data%\xlaborswb.mod

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_CHEPRO.CPL. 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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