Classification

Category :

Malware

Type :

Worm

Aliases :

Bizex, Worm.Win32.Bizex, W32.Bizex.Worm, Java/Bizex.A

Summary

Bizex is a multi-component ICQ worm that spreads itself by sending an instant message with a link to a website that contains files with exploits. The main component of the worm also has spying and data stealing capabilities.

The web page were Bizex file was located is not available anymore.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

Bizex worm spreads by sending an HTTP link to all ICQ contacts of an infected user. When a recipient clicks on a link, he/she is redirected to a website that has an HTML page with IFrame exploit. This exploit allows automatic execution of target files when Internet Explorer web browser is used. The HTML page concerned tries to autoexecute these 2 files:

meine.scm
user_bx.html
 

The MEINE.SCM file is downloaded from the same site and the USER_BX.HTML file is downloaded from a different website. The USER_BX.HTML file downloads and tries to execute Java trojan downloader nocheat.jar (detected as Java/Bizex.A).

The Java/Bizex.A is used for downloading and executing two windows binaries and informing server where user_bx.html was downloaded whether operation was successful including users browser and user agent version information. The Java/Bizex.A tries to execute these 2 files:

fgc32.exe
fgc64.exe
 

The MEINE.SCM file is an ICQ sound scheme file that is dropped to a \Sounds subfolder located in the main ICQ directory. This sound scheme file contains a CHM archive inside its body. The CHM archive is then activated by the webpage and it drops and opens a file called IEF*CKER.HTM.

This file contains a Visual Basic Script code that drops a file WinUpdate.exe. This binary file is a trojan downloader. Depending on the Windows version the script saves the trojan downloader in a folder:

C:\Documents and Settings\All Users\Start Menu\Programs\Startup\WinUpdate.exe
 

or

c:\windows\Start Menu\Programs\Startup\WinUpdate.exe
 

By placing WinUpdate.exe in the startup folder, the script code makes sure that the trojan downloader is run during next Windows restart.

When it is activated, the trojan downloader copies itself as ALSDFKJ.EXE file to a temporary folder and then downloads and activates the main worm's component as APTGETUPD.EXE file. This file is downloaded to a temporary folder.

The main worm's component is a PE executable 86528 bytes long packed with PECompact file compressor. When it is run, it deletes its file from a temporary folder, creates SYSMON subfolder in Windows System folder and copies itself there with the SYSMON.EXE name. It also drops 4 files from its body to Windows system folder:

ICQ2003Decrypt.dll
icq_socket.dll
javaext.dll
java32.dll
 

Additionally the XTEMPX.$ file is created in Windows System folder. Two of the dropped DLL files allow the worm to spread via ICQ, the other two are used to spy against an infected user. The worm creates a startup key for its file in the Registry:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"sysmon" = "%winsysdir%\sysmon.exe"
 

where %winsysdir% represents Windows System folder name. It should be noted that this Registry key can be only seen when Windows is started in Safe Mode as the worm uses stealth techniques to hide its Registry key.

The worm steals information from users of the following on-line services:

SUNCORP METWAY
VeriSign Partner Manager
VeriSign Personal Trust Service
Commercial Electronic Office Sign On
Wells Fargo - Small Business Home Page
Merchant Administration
American Express UK - Personal Finance
Secure User Area
Barclaycard Merchant Services
Collegamento a Scrigno
Home Page Banca Intesa
Banque
Tous les produits et services
Banque en ligne
Banamex.com
CyberMUT
Credit Lyonnais interacti
Accueil Bred.fr > Espace Bred.fr
Page d'accueil
E*TRADE Log On
LloydsTSB online - Welcome
Acceso a Banca por Internet
baNK
e-gold Account Access
 

Additionally the worm records user's keystrokes on an infected computer and monitors his/her HTTP traffic. The stolen data is copied to the following files:

~pass.log
~key.log
~post.log
 

These files are then uploaded by the worm to an ftp site, that mot likely belongs to the worm's author.

To disinfect a computer from this worm it's enough to delete its files from a hard drive. Manual disinfection should be performed in Safe Mode.