TROJ_ISTZONE.H

Malware type: Trojan

Aliases: Trojan-Downloader.Win32.Small.qd (Kaspersky), Downloader-NI (McAfee), SecurityRisk.Downldr (Symantec), TR/Dldr.Small.QD.1 (Avira),

In the wild: Yes

Destructive: No

Language: English

Platform: Windows 95, 98, ME, NT, 2000, XP

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:

Medium

Distribution potential:

Low

Description: 

This memory-resident Trojan redirects an affected user's Web browser to adult and promotional sites.

It then installs several programs without the user's consent on affected machines. Some of the said programs, which are usually adware and spyware programs, are detected by Trend Micro as the following:

It runs on Windows 95, 98, ME, NT, 2000, and XP.

For additional information about this threat, see:

Description created: Oct. 28, 2004 5:30:38 AM GMT -0800


TECHNICAL DETAILS


Size of malware: 11,679 Bytes

Initial samples received on: Oct 20, 2004

Details:

Autostart

This memory-resident Trojan creates the following autostart entries to ensure its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\Softwarwe\Microsoft\
Windows\CurrentVersion\Run
180ax = "%Windows%\180ax.exe"

HKEY_LOCAL_MACHINE\Sofwtare\Microsoft\
Windows\CurrentVersion\Run
ipmxyt = "%Windows%\ipmxyt.exe"

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
Games toolbar = "rundll32.exe "%Program files%\Games\tbGame.dll" DllShowTB"

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT. %Program Files% is the default Program Files folder, usually C:\Program Files.)

Downloader

Upon execution, this Trojan downloads and installs several programs without the user's consent on affected machines. Some of the said programs, which are usually adware and spyware programs, are detected by Trend Micro as the following:

It registers the said programs by adding the following registry keys:

HKEY_CURRENT_USER\Software\180ax

HKEY_LOCAL_MACHINE\Software\180ax

HKEY_LOCAL_MACHINE\Software\Games\toolbar

HKEY_LOCAL_MACHINE\Software\TopConverting

HKEY_LOCAL_MACHINE\Software\TopConverting\pacman

Other Details

This Trojan redirects an affected user's Web browser to adult sites and other promotional Web sites. It is compressed using EXEStealth.




Analysis by: Zarestel Ferrer


SOLUTION


Minimum scan engine version needed: 6.810

Pattern file needed: 2.207.05

Pattern release date: Oct 20, 2004


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:

(Before proceeding with the removal instructions, please disconnect first your Internet connection. Refer also to the clean instruction of ADW_NCASE.A, ADW_SOLU180.A, and ADW_SOLU180.D.)

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 all files detected as TROJ_ISTZONE.H.

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

Restarting in Safe Mode

� On Windows 95

  1. Restart your machine.
  2. Press F8 at the Starting Windows 95 message.
  3. Choose Safe Mode from the Windows 95 Startup Menu then press Enter.

� On Windows 98 and ME

  1. Restart your computer.
  2. Press the CTRL key until the Windows 98 startup menu appears.
  3. Choose the Safe Mode option then press Enter.

� On Windows NT (VGA mode)

  1. Click Start>Settings>Control Panel.
  2. Double-click the System icon.
  3. Click the Startup/Shutdown tab.
  4. Set the Show List field to 10 seconds and click OK to save this change.
  5. Shut down and restart your computer.
  6. Select VGA mode from the startup menu.

� On Windows 2000

  1. Restart your computer.
  2. Press the F8 key, when you see the Starting Windows bar at the bottom of the screen.
  3. Choose the Safe Mode option from the Windows Advanced Options Menu then press Enter.

� On Windows XP

  1. Restart your computer.
  2. Press F8 after the Power-On Self Test (POST) is done. If the Windows Advanced Options Menu does not appear, try restarting and then pressing F8 several times after the POST screen.
  3. Choose the Safe Mode option from the Windows Advanced Options Menu then press Enter.

Note: After performing all the solutions for the removal of this malware, please restart your system normally, and run your Trend Micro antivirus product.

Terminating the Malware Program

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

  1. Open Windows Task Manager.
    � On Windows 95, 98, and ME, press
    CTRL%20ALT%20DELETE
    � On Windows NT, 2000, and XP, 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 95, 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.

Uninstalling Downloaded Applications

  1. Uninstall donwloaded applications. Click Start>Control>Panel
  2. Select Add/Remove Programs
  3. Look for the following applications then click the Change/Remove or Add/Remove button:
    • 180ax
    • pacman Game
    • Games toolbar
  4. Restart your computer.

Resetting Internet Explorer Home Page and Search Page

This procedure restores the Internet Explorer home page and search page to the default settings.

  1. Close all Internet Explorer windows.
  2. Open Control Panel. Click Start>Settings>Control Panel.
  3. Double-click the Internet Options icon.
  4. In the Internet Properties window, click the Programs tab.
  5. Click the Reset Web Settings� button.
  6. Select Also reset my home page. Click Yes.
  7. Click OK.

Additional 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 sets.

Running Trend Micro Antivirus

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


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