TROJ_DIALER.CM

Malware type: Trojan

Aliases: Trojan-Downloader.Win32.Dluca.bv (Kaspersky), Generic Downloader.be (McAfee), Downloader (Symantec), TR/Dldr.Dluca.BV.1 (Avira), Mal/Heuri-E (Sophos),

In the wild: Yes

Destructive: No

Language: English

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

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:

Medium

Distribution potential:

Low

Description: 

A Trojan application is a malware with no capability to spread into other systems. They are usually downloaded from the Internet and installed by unsuspecting users.

This Trojan drops a copy of itself in the Windows system folder and in order to avoid detection, it deletes the original file after execution.

It uses a predetermined list to search the Program Files folder of the affected system for installed dialer programs. If any installed dialer programs are found, it uses the said programs to gain access to various adult Web sites.

In certain cases wherein a connection cannot be established due to missing or uninstalled drivers, this Trojan displays a message prompting the user to install the appropriate drivers from the Windows Installation CD.

For additional information about this threat, see:

Description created: Aug. 22, 2005 2:39:02 AM GMT -0800


TECHNICAL DETAILS


File type: PE

Memory resident:  Yes

Size of malware: 43,008 Bytes (compressed); ~122,880 Bytes (uncompressed)

Initial samples received on: Aug 18, 2005

Payload 1: Accesses adult Web sites via installed dialer programs

Payload 2: Searches the affected system for installed dialer programs

Details:

A Trojan application is a malware with no capability to spread into other systems. They are usually downloaded from the Internet and installed by unsuspecting users.

When executed, this Trojan drops a copy of itself in the Windows system folder as JPUPD.EXE. In order to avoid detection, it deletes the original file after execution.

It then creates the following registry entry to ensure its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
jpupd = "%System%\jpupd.exe /nocomm"

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 95, 98, and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and 2003.)

It also creates the following registry key that contains information regarding itself and its uninstallation:

HKEY_CURRENT_USER\Software\Siteicons\Dialers

It uses a predetermined list to search the Program Files folder of the affected system for installed dialer programs. If any installed dialer programs are found, it uses the said programs to gain access to various adult Web sites.

In certain cases wherein a connection cannot be established due to missing or uninstalled drivers, this Trojan displays a message prompting the user to install the appropriate drivers from the Windows Installation CD.

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

Analysis By: Jasper Aldous Elli Pimentel


SOLUTION


Minimum scan engine version needed: 6.810

Pattern file needed: 2.799.00

Pattern release date: Aug 24, 2005


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:

Terminating the Malware Program

This procedure terminates the running malware process.

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 NT, 2000, XP, and Server 2003, press
    CTRL%20SHIFT%20ESC, then click the Processes tab.
  2. In the list of running programs*, locate the process:
    JPUPD.EXE
  3. Select the malware process, then press either the End Task or the End Process button, depending on the version of Windows on your system.
  4. To check if the malware process has been terminated, close Task Manager, and then open it again.
  5. 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.

Deleting Malware File

  1. Right-click Start then click Search� or Find�, depending on the version of Windows you are running.
  2. In the Named input box, type:
    JPUPD.EXE
  3. In the Look In drop-down list, select the drive that contains Windows, then press Enter.
  4. Once located, select the file then press Delete.

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 NT 4.0
  3. HOW TO: Backup, Edit, and Restore the Registry in Windows 2000
  4. HOW TO: Back Up, Edit, and Restore the Registry in Windows XP and 2003

Removing Autostart Entries from the Registry

Removing autostart entries from the registry prevents the malware from executing at startup.

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:
    jpupd = "%System%\jpupd.exe /nocomm"

Removing Other Entries from the Registry

  1. Still in the Registry Editor, in the left panel, locate and delete the following subkey:
    HKEY_CURRENT_USER>Software>Siteicons>Dialers
  2. 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_DIALER.CM. 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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