Voici les résultats du rapport hijackthis :
(je pense que les clés "svchost" sont louches mais je ne suis sûre de rien...

Logfile of Trend Micro HijackThis v2.0.0 (BETA)
Scan saved at 20:50:05, on 08/08/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
Boot mode: Normal

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:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\WINDOWS\system32\wscntfy.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\svchost.exe
C:\PROGRA~1\Wanadoo\CnxMon.exe
C:\PROGRA~1\Wanadoo\TaskbarIcon.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\SAGEM\SAGEM F@st 800-840\dslmon.exe
C:\PROGRA~1\Wanadoo\EspaceWanadoo.exe
C:\PROGRA~1\Wanadoo\ComComp.exe
C:\PROGRA~1\Wanadoo\Watch.exe
C:\Program Files\Alwil Software\Avast4\setup\avast.setup
C:\Documents and Settings\Jennifer\Bureau\HiJackThis_v2.exe
C:\Program Files\MSN Messenger\msnmsgr.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://www.wanadoo.fr/go/page_recherche/
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.wanadoo.fr
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Wanadoo
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
R3 - URLSearchHook: Search Class - {08C06D61-F1F3-4799-86F8-BE1A89362C85} - C:\PROGRA~1\Wanadoo\SEARCH~1.DLL
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: (no name) - {C7FF938D-3B55-A82E-A83E-5AFE5C47B9AA} - C:\DOCUME~1\Jennifer\APPLIC~1\32DENT~1\win locks.exe (file missing)
O4 - HKLM\..\Run: [WooCnxMon] C:\PROGRA~1\Wanadoo\CnxMon.exe
O4 - HKLM\..\Run: [WOOWATCH] C:\PROGRA~1\Wanadoo\Watch.exe
O4 - HKLM\..\Run: [WOOTASKBARICON] C:\PROGRA~1\Wanadoo\TaskbarIcon.exe
O4 - HKLM\..\Run: [NeroCheck] C:\WINDOWS\system32\\NeroCheck.exe
O4 - HKLM\..\Run: [KernelFaultCheck] %systemroot%\system32\dumprep 0 -k
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKLM\..\Policies\Explorer\Run: [5T19I3B27A] C:\WINDOWS\svchost.exe
O4 - HKUS\S-1-5-19\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-20\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SERVICE RÉSEAU')
O4 - HKUS\S-1-5-18\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'Default user')
O4 - Global Startup: DSLMON.lnk = C:\Program Files\SAGEM\SAGEM F@st 800-840\dslmon.exe
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O15 - Trusted Zone: *.p0rt2.com
O17 - HKLM\System\CCS\Services\Tcpip\..\{DC7EF72B-AE88-454A-B05A-2EBB8BD1E8BA}: NameServer = 80.10.246.1 80.10.246.132
O21 - SSODL: printers - {09CEB233-88E9-48BD-B12E-F42EB21FE6CA} - libwinets.dll (file missing)
O22 - SharedTaskScheduler: Pré-chargeur Browseui - {438755C2-A8BA-11D1-B96B-00A0C90312E1} - C:\WINDOWS\system32\browseui.dll
O22 - SharedTaskScheduler: Démon de cache des catégories de composant - {8C7461EF-2B13-11d2-BE35-3078302C2030} - C:\WINDOWS\system32\browseui.dll
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: avast! Antivirus - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
O23 - Service: avast! Web Scanner - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
O23 - Service: Service d'administration du Gestionnaire de disque logique (dmadmin) - Unknown owner - C:\WINDOWS\System32\dmadmin.exe
O23 - Service: Journal des événements (Eventlog) - Unknown owner - C:\WINDOWS\system32\services.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Fichiers communs\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: Service COM de gravage de CD IMAPI (ImapiService) - Unknown owner - C:\WINDOWS\system32\imapi.exe
O23 - Service: Partage de Bureau à distance NetMeeting (mnmsrvc) - Unknown owner - C:\WINDOWS\system32\mnmsrvc.exe
O23 - Service: Plug-and-Play (PlugPlay) - Unknown owner - C:\WINDOWS\system32\services.exe
O23 - Service: Gestionnaire de session d'aide sur le Bureau à distance (RDSessMgr) - Unknown owner - C:\WINDOWS\system32\sessmgr.exe
O23 - Service: Carte à puce (SCardSvr) - Unknown owner - C:\WINDOWS\System32\SCardSvr.exe
O23 - Service: Journaux et alertes de performance (SysmonLog) - Unknown owner - C:\WINDOWS\system32\smlogsvc.exe
O23 - Service: Cliché instantané de volume (VSS) - Unknown owner - C:\WINDOWS\System32\vssvc.exe
O23 - Service: Carte de performance WMI (WmiApSrv) - Unknown owner - C:\WINDOWS\system32\wbem\wmiapsrv.exe
End of file - 5232 bytes