Description: 

When run, this backdoor program opens a port then waits for an outside connection. Once a port is opened, the infected system becomes an easy target to malicious users who can connect and gain access to the system using Telnet or other similar programs which are used for remote connection.

It displays the following fake error message:

Then, it downloads the file, logonui32.bin, which is an updated copy of itself from the following sites:

• http://www.geocities.com/haz<BLOCKED>lten/
• http://www.geocities.com/pet<BLOCKED>r0xf0rd/
• http://www.geocities.com/kks<BLOCKED>wnz/

This non-memory resident backdoor runs on Windows 95, 98, ME, NT, 2000, XP and is compiled using Visual Basic 6, a high-level programming language.

Details:

Installation

Upon execution, this backdoor program creates a copy of itself as loginui32.exe in the Windows folder.

(Note: The Windows folder is usually located at C:\Windows for Windows 95/98/ME/XP systems or C:\Winnt for WinNT/2000.)

Then, it creates an autorun entry in the registry to ensure its automatic execution at every Windows startup:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
loginui32 = "%Windows%\loginui32.exe"

Backdoor Features

Once active in memory, it opens up a port, then waits for an outside connection. Malicious remote users can then gain access to the infected machine by connecting to the opened port via TelNet or other similar programs used to connect to remote computers.

By default, this backdoor malware opens up 50305.

It is also designed to download newer versions of itself from the following sites:

• http://www.geocities.com/hazzelten/
• http://www.geocities.com/peter0xf0rd/
• http://www.geocities.com/kks0wnz/

At the time of this writing, the logonui32.bin file is an updated version of the original backdoor malware and has the following added features:

• creates the file named NetCruz.log, in the Windows folder. This file logs the backdoor's activity and execution.
• sends an ICQ Notification to the malicious users ICQ number

Other Details

This non-memory resident backdoor malware displays the following fake error message:

It runs on Windows 95, 98, ME, NT, 2000, and XP and is compiled using Visual Basic 6.

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:

Identifying the Malware Program

Before proceeding to remove this malware, first identify the malware program.

Scan your system with Trend Micro antivirus and NOTE all files detected as . 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.

Terminating the Malware Program

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

1. Open Windows Task Manager.
   On Windows 95/98/ME systems, press
   CTRL+ALT+DELETE
   On Windows NT/2000/XP systems, press
   CTRL+SHIFT+ESC, then click the Processes tab.
2. In the list of running programs*, locate the malware file or files 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/ME, Task Manager may not show certain processes. You may use a third party process viewer to terminate the malware process. Otherwise, continue with the next procedure, noting additional instructions.

Removing Autostart Entries from the Registry

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

1. Open Registry Editor. To do this, 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:
   loginui32 = "%Windows%\loginui32.exe"
   Note: %Windows% is the default Windows folder, usually C:\Windows or C:\WinNT.
4. Close Registry Editor.

Deleting Dropped Files

On Windows 9x/NT

1. Click Start>Find>Files and Folders.
2. In the Named input box, type:
   
3. In the Look In drop-down list, select the drive which contains Windows, then press Enter.

1. Click Start>Search>For Files and Folders.
2. In the Search for files and folders named input box, type:
   
3. In the Look In drop-down list, select the drive which contains Windows, then press Enter.

Once found, manually delete the file.

Running Trend Micro Antivirus

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

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