ALIASES:

Trojan.ADH (Symantec); Backdoor.Win32.Hupigon.swza (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Generic10_c.CMQB (AVG)

 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.

  TECHNICAL DETAILS

File Size: 3,458,420 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 19 Jun 2014

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.

Autostart Technique

This Trojan modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "{random characters}"

(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)

Other System Modifications

This Trojan deletes the following files:

  • %Common Startup%\InstallShield.exe

(Note: %Common Startup% is the system's shared Startup folder, which is usually C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\WinRAR SFX

HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\
RemoteNotes

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\MediaResources\msvideo

It adds the following registry entries:

HKEY_CURRENT_USER\Software\WinRAR SFX
C%%Program Files%Windows NT% = "%Program Files%\Windows NT"

Dropping Routine

This Trojan drops the following files:

  • __tmp_rar_sfx_access_check_121453
  • demo.mp4
  • urls.xml
  • FreeJapanAV.ini
  • InstallShield.xml
  • FreeJapanAV.exe
  • %Common Startup%\demo.mp4
  • %Program Files%\Windows Media Player\rcimlby.exe
  • %Program Files%\Common Files\Microsoft Shared\MSINFO\rcimlby.exe

(Note: %Common Startup% is the system's shared Startup folder, which is usually C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}.219.77

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.700

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

Identify and delete files detected as TROJ_CRYPT.VTX using either the Startup Disk or Recovery Console

[ Learn More ]

Step 3

Delete this registry key

[ 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
    • WinRAR SFX
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Adobe
    • RemoteNotes
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MediaResources
    • msvideo

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\WinRAR SFX
    • C%%Program Files%Windows NT% = "%Program Files%\Windows NT"

Step 5

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: Userinit = "{random characters}"
      To: Userinit = ""%Windows%\system32\userinit.exe,""

Step 6

Search and delete these components

[ Learn More ]
There may be some components 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.
  • __tmp_rar_sfx_access_check_121453
  • demo.mp4
  • urls.xml
  • FreeJapanAV.ini
  • InstallShield.xml
  • FreeJapanAV.exe
  • %Common Startup%\demo.mp4
  • %Program Files%\Windows Media Player\rcimlby.exe
  • %Program Files%\Common Files\Microsoft Shared\MSINFO\rcimlby.exe

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_CRYPT.VTX. 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.

Step 8

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Common Startup%\InstallShield.exe


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