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F-Secure Virus Descriptions : IRCBot.et

[Summary] | [Disinfection] | [Detailed Description] | [Detection]



NAME:IRCBot.et
ALIAS:Backdoor.Win32.IRCBot.et, W32.Zotob.D, W32/Dogbot-A
SIZE:51326

Summary

A new variant of a bot spreading the Plug and Play service (MS05-039) vulnerability has been found on August, 16th 2005.

Disinfection

F-Secure provides the special disinfection utility to eliminate this malware infection. You can download this utility from our ftp or web sites:

http://www.f-secure.com/tools/f-bot.zip

ftp://ftp.f-secure.com/anti-virus/tools/f-bot.zip

The unpacked version is available here:

http://www.f-secure.com/tools/f-bot.exe

ftp://ftp.f-secure.com/anti-virus/tools/f-bot.exe

Disinfection instructions can be found here:

http://www.f-secure.com/tools/f-bot.txt

ftp://ftp.f-secure.com/anti-virus/tools/f-bot.txt

If the infection is in a local network, please follow the instructions on this webpage:

http://www.f-secure.com/v-descs/netdisinf.shtml

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Detailed Description

The worm is a packed PE executable file 51326 bytes long.

Installation to system

When run, the worm copies under %SYSTEM% directory using the name 'windrg32.exe'.

Then it adds the following registry entries to ensure that it is started when a user logs on or the system is restarted:

 [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
 "winDrg32" = "windrg32.exe"

Spreading using Plug and Play service vulnerability

The worm scans for systems vulnerable to Microsoft Windows Plug and Play service (MS05-039) through TCP/445.

Here's the summary of the ports used in attack:

Port 445 - The worm scans for systems vulnerable to PnP exploit through this port

Port 29463 - FTP server port on infected systems

Port 6667 - The command shell port opened by the exploit code

Please see the following page for detailed information on the vulnerability:

http://www.microsoft.com/technet/security/Bulletin/MS05-039.mspx

Bot functionality

The worm tries to connect to IRC channel at predefined address. The attacker who knows channel password can instruct the bot to execute the following actions:

 Disconnect/reconnect from the IRC channel
 Request system information
 Download and execute files
 Remove worm from the system
 Manipulate system security settings

Other details

IRCBot.et tries to uninstall some other malware and adware by deleting files and folders and removing registry keys.

The worm tries to terminates the following processes:

 botzor.exe		(Net-Worm.Win32.Mytob.cd / Zotob.A)
 CMESys.ex
 csm.exe		(Net-Worm.Win32.Mytob.cf / Zotob.B)
 CxtPls.exe
 NHUpdater.exe
 pnpsrv.exe		(Backdoor.Win32.Rbot.yk
 qttask.exe
 realsched.exe
 ViewMgr.exe
 winpnp.exe		(Backdoor.Win32.Rbot.ym)

It tries to delete the following registry values:

 [HKCU\Software\Microsoft\Windows\Run]
 "180"
 "180ax"
 "Apropos"
 "AutoUpdater"
 "CMESys"
 "csm Win Updates"
 "Ebates"
 "EbatesMoeMoneyMaker"
 "eZmmod"
 "eZula"
 "Gator"
 "GatorDownloader"
 "Hotbar"
 "IBIS TB"
 "lgbibsn"
 "msbb"
 "MyWay"
 "MyWebSearch"
 "NavExcel"
 "QuickTime"
 "QuickTime Task"
 "Real"
 "saie"
 "sais"
 "TBPS"
 "TkBellExe"
 "Toolbar"
 "tov"
 "Trickler"
 "ViewMgr"
 "Viewpoint"
 "WeatherOnTray"
 "Windows PNP"
 "Windows PNP Server"
 "WINDOWS SYSTEM"
 "WinTools"
 "Zotob"

The worm also tries to delete the following files and folders:

 %ProgramFiles%\180Solutions
 %ProgramFiles%\180Solutions\*.exe
 %ProgramFiles%\AutoUpdate
 %ProgramFiles%\AutoUpdate\AutoUpdate.exe
 %ProgramFiles%\Common Files\CMEII
 %ProgramFiles%\Common Files\GMT
 %ProgramFiles%\Common Files\GMT\GMT.exe
 %ProgramFiles%\Common Files\WinTools
 %ProgramFiles%\Common Files\WinTools\*.exe
 %ProgramFiles%\CxtPls
 %ProgramFiles%\EbatesMoeMoneyMaker
 %ProgramFiles%\eZula
 %ProgramFiles%\eZula\mmod.exe
 %ProgramFiles%\Hotbar
 %ProgramFiles%\Hotbar\*.exe
 %ProgramFiles%\MyWay
 %ProgramFiles%\MyWay\*.exe
 %ProgramFiles%\MyWebSearch
 %ProgramFiles%\MyWebSearch\*.exe
 %ProgramFiles%\NavExcel
 %ProgramFiles%\Toolbar
 %ProgramFiles%\Toolbar\*.exe
 %System%\botzor.exe
 %System%\csm.exe
 %System%\pnpsrv.exe
 %System%\winpnp.exe


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Detection

[FSAV_Database_Version]

Version=2005-08-16_1


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Technical Details: Jarkko Turkulainen & Ero Carrera; Aug 16th, 2005;

Updated: Jarkko Turkulainen; Aug 17th, 2005;

Updated: Jarkko Turkulainen; Aug 18th, 2005;

F-Secure Corporation