Worm:W32/Benjamin

Summary

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A standalone malicious program which uses computer or network resources to make complete copies of itself.

Removal

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Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.

More

Detailed instructions for F-Secure security products are available in the documentation found in the Downloads section of our Home - Global site.

You may also refer to the Knowledge Base on the F-Secure Community site for further assistance.

Technical Details

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The Benjamin worm uses KaZaa Peer-To-Peer (P2P) network to spread. The KaZaa network allows its participants to exchange files with each other, using the special client software. The worm opens benjamin.xww.de Web-site to view an advertisement. The worm is written in Borland Delphi and is about 216 kilobytes long. The worm's file is compressed with ASPack file compressor. Besides the worm uses a decoy - it appends random data to its end that increases its size 2-3 times.

Execution

When the worm's file is started, it shows a fake error message: Error Access error #03A:94574: Invalid pointer operation File possibly corrupted. Then it copies itself into Windows System directory as EXPLORER.SCR and creates two keys in the System Registry:

• [HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run] "System-Service"="C:\\WINDOWS\\SYSTEM\\EXPLORER.SCR"
• [HKEY_LOCAL_MACHINE\Software\Microsoft] "syscod"="0065D7DB20008306B6A1"

This way, the worm makes sure that it is always executed when Windows starts.

Propagation (P2P)

The worm spreads only from and to computers where KaZaa network clients are installed. The worm reads the settings of the KaZaa client from the System Registry, creates the directory named \Sys32\ in Windows Temp folder and makes this directory visible to all clients of Kazaa network. The worm then fills this directory with its copies with various names which are taken from the list inside the worm's body. The list contains numerous titles of popular software, movies, games and music, and some commonly used search words. For example, this is only the part of the list with titles starting with 'A' letter:

• ...
• A.I-Artificial Intelligence- divx -full-downloader
• A.I-Artificial Intelligence- Filme -full-downloader
• ABeautifulMind
• AbsoluteZero-installer
• acdsee4
• ACDSeePowerPackRetail-installer
• Adobe InDesign 2.0 Build 416 -full-downloader
• Adobe Pagemaker -full-downloader
• Adobe Photoshop 6.0 -full-downloader
• Adobe Photoshop update (6.1) -full-downloader
• Adobe-Streamline-installer
• Adress Genie 4.0-full-downloader
• After Dark Deluxe-Bildschirmschoner-full-downloader
• Age of Empires 2- Games -full-downloader
• Age of Empires 2 Gold +Strat.Comm.-Games-full-downloader
• Age of Empires 2 Gold +Strat.Comm.-Spiel-full-downloader
• Age of Empires 2-Spiel-full-downloader
• Age of Empires Screensaver
• Age of Empires-Games-full-downloader
• Age of Empires-spiel-full-downloader
• Age of Mythology - Games -full-downloader
• Age of Mythology (Beta) -full-downloader
• Age of Mythology-installer
• Age of Wonders II The Wizard#39s-installer
• Airxonix -full-downloader
• AirxonixGeschicklichkeit
• Alarm Stufe Rot 2 -full-downloader
• Alarm Stufe Rot 2 Yuris Rache -full-downloader
• Alfred Hitchcock - The Final Cut - Games -full-downloader
• Alice-full-installer
• Alien vs. Predoator 2-Games-full-downloader
• Alien vs. Predoator 2-Spiel-full-downloader
• Aliens versus Predator 2 -full-downloader
• Aliens Versus Predator 2-installer
• Aliens versus Predator -full-downloader
• AliZaoua
• All Serials
• All Serialz
• Allout-Games-full-downloader
• Almost Famous-Komödie-Filme-full-downloader
• American McGee#39s Alice-Games-full-downloader
• American McGee#39s Alice-spiel-full-downloader
• American Pie 2 -divx-full-downloader
• American Pie 2- Filme -full-downloader
• American Pie 2-divx-full-downloader
• American Pie -divx-full-downloader
• Anam
• Anarchy Online-Games-full-downloader
• Anarchy Online-Spiel-full-downloader
• Animal
• Anno 1503 (Beta) -full-downloader
• Anno 1503- Games -full-downloader
• Anno 1503-Spiel-full-downloader
• Anno 1602 Königs Edition Classic- Games -full-downloader
• Anno 1602 Königs Edition Classic-Spiel-full-downloader
• Anstoss 3 -full-downloader
• Anti Hacker-Program 2002-full-downloader
• Appz
• Aquanox -full-downloader
• aquanox-full-downloader
• Aquanox-full-instaler
• ArmySargeHero
• ARX Fatalis-installer
• ARXFatalis
• Asheron#39s Call 2-installer
• Assessment Center-full-downloader
• Astalavista
• AsterixundOberlix

...

The worm spreads in the following way: a KaZaa network user searches for any file (for example the file that has the 'game' string in its file name) in the KaZaa network and finds it on the list of accessible files from an infected computer. The user downloads this file and starts it, thus infecting his own machine.

Detection

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F-Secure Anti-Virus detects Benjamin worm with the updates published in May 20th, 2002:
Database: 2002-05-20_03