TROJ_JUNY.A

Malware type: Trojan

Aliases: Virus.Win32.JuNy.a (Kaspersky), W32/Generic.Delphi.b (McAfee), Trojan.Juny (Symantec), TR/Spy.Lydra.F.4 (Avira), Troj/Juny-A (Sophos), Trojan:Win32/Juny.A.dll (Microsoft)

In the wild: Yes

Destructive: No

Language: English

Platform: Windows 98, ME, 2000, XP, Server 2003

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:

High

Distribution potential:

Low

Description: 

When executed, this memory-resident Trojan encrypts files with certain extensions names on the affected system using a special encryption routine. It lists the files it encrypts in a text file named !.TXT, which roughly translates from Russian to English as PIZDETS TO YOU IN GUESTS!.TXT.

File encryption is tyically used as a security measure to prevent unauthorized users from accessing or viewing the contents of files, thus preserving their integrity. Since this Trojan employs the same routine, users will not be able to access the affected files without a decryption tool.

When run, this Trojan displays a message box in Russian text that warns an affected user with this Trojan, and then asks the said user for payment in exchange for decrypting the files. It even provides the email address that receives requests for the said decryption service, provided that the user pays the "ransom" first.

For additional information about this threat, see:

Description created: Oct. 18, 2005 8:10:42 PM GMT -0800


TECHNICAL DETAILS


File type: PE

Memory resident:  Yes

Size of malware: 68,096 Bytes

Initial samples received on: Oct 17, 2005

Payload 1: Displays message

Trigger condition 1: Upon execution

Payload 2: Employs shell spawning

Trigger condition 1: Whenever .EXE files are executed

Payload 3: Encrypts files

Trigger condition 1: Upon execution

Details:

Installation and Autostart Technique

This memory-resident Trojan drops the file ������ � ��� � �����!.TXT, which roughly translates from Russian to English as PIZDETS TO YOU IN GUESTS!.TXT. The said file contains a list of all the files it encrypts using a special encrypting routine.

Upon execution, it displays a message box in Russian text to warn a user that a system is infected with this Trojan. It then asks for payment in exchange for decrypting the mentioned files, and provides an email address that receives requests for the said service.

This Trojan creates the following registry entries to ensure its automatic execution at every Windows startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Kernel Manager = �%System%\krnlmgr.exe�

(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.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Kernel Manager = �%System%\krnlmgr.exe�

It also adds the following registry key as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
EventSystem.EventSystem\PrivateData\FuckedBytes

This Trojan also employs its shell spawning technique to automatically execute this Trojan whenever an .EXE file is executed. It performs the said routine by modifying the following registry entry:

From

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
exefile\open\command
"%1" %*"

To

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
exefile\open\command
�%System%\krnlmgr.exe�%1� %*�

File Encryption

This Trojan encrypts files with the following file types:

Once the target files are encrypted, they can no longer be executed by the user. It may also affect the said files by modifying their codes or contents.

Other Details

This Trojan runs on Windows 98, ME, 2000, XP, and Server 2003.

Analysis By: Jay-R Tan

Revision History:

First pattern file version: 2.900.01
First pattern file release date: Oct 18, 2005
 
Oct 20, 2005 - Updated Pattern br>October 25, 2005 - Insertion of Automatic Removal Instructions

SOLUTION


Minimum scan engine version needed: 7.000

Pattern file needed: 3.204.03

Pattern release date: Feb 9, 2006


Important note: The "Minimum scan engine" refers to the earliest Trend Micro scan engine version guaranteed to detect this threat. However, Trend Micro strongly recommends that you update to the latest version in order to get comprehensive protection. Download the latest scan engine here.

Solution:

AUTOMATIC REMOVAL INSTRUCTIONS

MANUAL REMOVAL INSTRUCTIONS

Identifying the Malware Program

To remove this malware, first identify the malware program.

  1. Scan your system with your Trend Micro antivirus product.
  2. NOTE the path and file name of all files detected as TROJ_JUNY.A.

Trend Micro customers need to download the latest virus pattern file before scanning their system. Other users can use Housecall, Trend Micro's online virus scanner.

Terminating the Malware Program

This procedure terminates the running malware process. You will need the name(s) of the file(s) detected earlier.

If the process you are looking for is not in the list displayed by Task Manager, proceed to the succeeding solution set.

  1. Open Windows Task Manager.
    • On Windows 98 and ME, press
    CTRL%20ALT%20DELETE
    • On Windows 2000, XP, and Server 2003, press
    CTRL%20SHIFT%20ESC, then click the Processes tab.
  2. In the list of running programs*, locate the malware file(s) detected earlier.
  3. Select one of the detected files, then press either the End Task or the End Process button, depending on the version of Windows on your system.
  4. Do the same for all detected malware files in the list of running processes.
  5. To check if the malware process has been terminated, close Task Manager, and then open it again.
  6. Close Task Manager.

*NOTE: On systems running Windows 98 and ME, Windows Task Manager may not show certain processes. You can use a third party process viewer such as Process Explorer to terminate the malware process. Otherwise, continue with the next procedure, noting additional instructions. If you were not able to terminate the malware process as described in the previous procedure, restart your system.

Editing the Registry

This malware modifies the system's registry. Users affected by this malware may need to modify or delete specific registry keys or entries. For detailed information regarding registry editing, please refer to the following articles from Microsoft:

  1. HOW TO: Backup, Edit, and Restore the Registry in Windows 95, Windows 98, and Windows ME
  2. HOW TO: Backup, Edit, and Restore the Registry in Windows 2000
  3. HOW TO: Back Up, Edit, and Restore the Registry in Windows XP and Server 2003

Addressing Registry Shell Spawning

This procedure prevents the malware from executing whenever a user opens files with certain extension names. It should restore the registry to its original settings.

  1. Click Start>Run.
  2. In the Open input box, type:
    command /c copy %WinDir%\regedit.exe regedit.com | regedit.com
  3. Press Enter.
  4. In the left panel, double-click the following:
    HKEY_CLASSES_ROOT>exefile>shell>open>command
  5. In the right panel, locate the registry entry:
    Default
  6. Check whether its value is the path and file name of the malware file.
  7. If the value is the malware file, right-click Default and select Modify to change its value.
  8. In the Value data input box, delete the existing value and type the default value:
    "%1"%*
  9. Close Registry Editor.
  10. Click Start>Run, then type:
    command /c del regedit.com
  11. Press Enter.

Removing Autostart Entries from the Registry

Removing autostart entries from the registry prevents the malware from executing at startup. In this procedure, you will need the name(s) of the file(s) detected earlier.

If the registry entries below are not found, the malware may not have executed as of detection. If so, proceed to the succeeding solution set.

  1. Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
  2. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>
    Windows>CurrentVersion>Run
  3. In the right panel, locate and delete the entry or entries whose data value is the malware path and file name of the file(s) detected earlier.
  4. Again in the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>
    Windows>CurrentVersion>Run
  5. In the right panel, locate and delete the entry or entries whose data value is the malware path and file name of the file(s) detected earlier.
  6. Close Registry Editor.

Important Windows ME/XP Cleaning Instructions

Users running Windows ME and XP must disable System Restore to allow full scanning of infected systems.

Users running other Windows versions can proceed with the succeeding procedure set(s).

Running Trend Micro Antivirus

Scan your system with Trend Micro antivirus and delete files detected as TROJ_JUNY.A. To do this, Trend Micro customers must download the latest virus pattern file and scan their system. Other Internet users can use HouseCall, Trend Micro's online virus scanner.




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