Voici le resultat du hijackthis

Logfile of HijackThis v1.99.1
Scan saved at 21:48:20, on 15/12/2006
Platform: Windows XP SP1 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\Explorer.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\AntiVir PersonalEdition Classic\sched.exe
C:\Program Files\AntiVir PersonalEdition Classic\avguard.exe
C:\WINDOWS\System32\Atievxx.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Fichiers communs\Totem Shared\Uninstall0001\upd.exe
C:\Program Files\AntiVir PersonalEdition Classic\avgnt.exe
C:\WINDOWS\System32\ctfmon.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Fichiers communs\Softwin\BitDefender Communicator\xcommsvr.exe
C:\Program Files\Fichiers communs\Softwin\BitDefender Scan Server\bdss.exe
C:\Program Files\Softwin\BitDefender Free Edition\bdmcon.exe
C:\Program Files\Softwin\BitDefender Free Edition\bdnagent.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\PROGRA~1\EACCEL~1\Station\station.exe
C:\PROGRA~1\ACCELE~1\ANTI-V~1\STOPSI~1.EXE
C:\Program Files\Acceleration Software\Anti-Virus\stopsignav.exe
C:\PROGRA~1\Yahoo!\MESSEN~1\YAHOOM~1.EXE
C:\Program Files\Messenger\MSMSGS.EXE
C:\Documents and Settings\Oumar Ag Ittaha\Local Settings\Temp\Répertoire temporaire 1 pour hijackthis.zip\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://fr.rd.yahoo.com/customize/ie/defaults/sp/msgr8/*https://fr.search.yahoo.com/
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://fr.yahoo.com/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://fr.rd.yahoo.com/customize/ie/defaults/su/msgr8/*https://fr.search.yahoo.com/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://fr.rd.yahoo.com/customize/ie/defaults/sp/msgr8/*https://fr.search.yahoo.com/
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://fr.rd.yahoo.com/customize/ie/defaults/su/msgr8/*https://fr.search.yahoo.com/
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
R3 - URLSearchHook: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
F2 - REG:system.ini: Shell=Explorer.exe "C:\WINDOWS\sembako-ckzjljh.exe"
F2 - REG:system.ini: UserInit=C:\WINDOWS\System32\Userinit.exe
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 6.0\Reader\ActiveX\AcroIEHelper.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\System32\msdxm.ocx
O3 - Toolbar: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O4 - HKLM\..\Run: [Bron-Spizaetus-ckhjlvow] "C:\WINDOWS\ShellNew\bbm-wovljhkc.exe"
O4 - HKLM\..\Run: [Bron-Spizaetus-anorbtok] "C:\WINDOWS\ShellNew\bbm-kotbrona.exe"
O4 - HKLM\..\Run: [Uninstall0001] "C:\Program Files\Fichiers communs\Totem Shared\Uninstall0001\upd.exe" LASTCALL!adverts.virtuagirl.com!StatsVirtuaGirl
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\AntiVir PersonalEdition Classic\avgnt.exe" /min
O4 - HKLM\..\Run: [BDMCon] C:\Program Files\Softwin\BitDefender Free Edition\\bdmcon.exe
O4 - HKLM\..\Run: [BDNewsAgent] C:\Program Files\Softwin\BitDefender Free Edition\\bdnagent.exe
O4 - HKLM\..\Run: [SoftwareStation] "C:\Program Files\eAcceleration\Station\station.exe" /b Startup
O4 - HKLM\..\Run: [StopSignSsTsMon] Rundll32.exe "C:\Program Files\Acceleration Software\Anti-Virus\sstsmon.dll",VerifyStatus
O4 - HKLM\..\Run: [webscan] "C:\Program Files\Acceleration Software\Anti-Virus\stopsignav.exe" -k
O4 - HKLM\..\RunOnce: [StopSignSsTsMon] Rundll32.exe "C:\Program Files\Acceleration Software\Anti-Virus\sstsmon.dll",VerifyStatus /ro
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\ctfmon.exe
O4 - HKCU\..\Run: [Tok-Cirrhatus-5259] "C:\Documents and Settings\Oumar Ag Ittaha\Local Settings\Application Data\br11541on.exe"
O4 - HKCU\..\Run: [Yahoo! Pager] "C:\PROGRA~1\Yahoo!\MESSEN~1\YAHOOM~1.EXE" -quiet
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\MSN Messenger\MsnMsgr.Exe" /background
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office10\OSA.EXE
O7 - HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System, DisableRegedit=1
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\MSMSGS.EXE
O9 - Extra 'Tools' menuitem: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\MSMSGS.EXE
O16 - DPF: {30528230-99f7-4bb4-88d8-fa1d4f56a2ab} (YInstStarter Class) - C:\Program Files\Yahoo!\Common\yinsthelper.dll
O23 - Service: AntiVir PersonalEdition Classic Scheduler (AntiVirScheduler) - Avira GmbH - C:\Program Files\AntiVir PersonalEdition Classic\sched.exe
O23 - Service: AntiVir PersonalEdition Classic Guard (AntiVirService) - AVIRA GmbH - C:\Program Files\AntiVir PersonalEdition Classic\avguard.exe
O23 - Service: BitDefender Scan Server (bdss) - Unknown owner - C:\Program Files\Fichiers communs\Softwin\BitDefender Scan Server\bdss.exe
O23 - Service: ScriptBlocking Service (SBService) - Symantec Corporation - C:\PROGRA~1\FICHIE~1\SYMANT~1\SCRIPT~1\SBServ.exe
O23 - Service: BitDefender Communicator (XCOMM) - Softwin - C:\Program Files\Fichiers communs\Softwin\BitDefender Communicator\xcommsvr.exe