TROJ_ISTZONE.B

Malware type: Trojan

Aliases: Trojan-Downloader.Win32.Small.qd (Kaspersky), Downloader-NI (McAfee), SecurityRisk.Downldr (Symantec), Worm/Rbot.SZ.1 (Avira), Trojan:Win32/IEZones.A (Microsoft)

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:

High

Distribution potential:

Low

Description: 

WORM_RBOT.AAJ drops this Trojan in the folder %Windows%\Config as the file LOUD.EXE.

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

The said worm executes this Trojan afterwards.

The Trojan attempts to download malware and adware/spyware programs from the following site:

    http://sa<BLOCKED>y97.net

The following malware and adware/spyware programs are downloaded:

The user is then redirected to the following adult entertainment site:

    http://amateur.freegayspace.com/leetage/loud.html

The Trojan also modifies the registry.

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

For additional information about this threat, see:

Description created: Nov. 2, 2004 12:51:03 AM GMT -0800
Description updated: Nov. 2, 2004 4:05:15 AM GMT -0800


TECHNICAL DETAILS


Size of malware: 7,583 Bytes

Initial samples received on: Nov 2, 2004

Related toTROJ_DELF.AR, SPYW_BISPY.A, ADW_NRD.A, ADW_SOLU180.D, SPYW_TWANT.E, SPYW_IESEARCH.A, ADW_NCASE.A, ADW_WUPD.A

Payload 1: Downloads adware programs

Trigger condition 1: Upon execution

Payload 2: Downloads other malware

Trigger condition 1: Upon execution

Payload 3: Modifies registry

Trigger condition 1: Upon execution

Details:

WORM_RBOT.AAJ drops this Trojan in the folder %Windows%\Config as the file LOUD.EXE.

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

The said worm executes this Trojan afterwards.

The Trojan attempts to download malware and adware/spyware programs from the following site:

    http://sa<BLOCKED>y97.net

The following malware and adware/spyware are downloaded:

The user is then redirected to the following adult entertainment site:

    http://amateur.freegayspace.com/leetage/loud.html

The Trojan also sets the value of the following registry entries to zero:

HKEY_CURRENT_USER\Software\Microsoft\Windows\
CurrentVersion\Internet Settings\Zones\3
� Flags
� 1001
� 1004
� 1201
� 1406
� 1609
� 1800
� 1804
� 1805
� 1A00
� 1A04
� 1A05
� 1A10
� 1206
� 2001
� 2004





Analysis by: Juan Cesar Cuevas


SOLUTION


Minimum scan engine version needed: 6.810

Pattern file needed: 2.229.05

Pattern release date: Nov 2, 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:

NOTE: Do not forget to perform the clean instructions for the following malware and adware/spyware programs:

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.B.

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.

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.

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.B. To do this, Trend Micro customers must download the latest pattern file and scan their system. Other users can use HouseCall, Trend Micro�s free online virus scanner.


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