problème moteur de recherche et mises à jour impossible

Bonjour,
j'ai depuis peu des problèmes avec mes moteurs de recherche: quand je clique sur un lien que proposent Google ou Yahoo, une page s'ouvre et je s'affiche un site qui n'a rien à voir avec le lien (ce sont souvent des sortes de moteurs de recherche bizarre, avec un lien començant par "go.google..." ).
J'ai donc téléchargé "Hijack this" et fait un scan rapide.
J'ai dû faire une bêtise, et éliminer des fichiers importants. Par la suite, toute mise à jour est devenue impossible, je ne peux même plus aller sur le site d'avast ou un site avec scan en ligne...
J'ai recommencé un scan avec "Hijack this", je vous envoie le rapport:
Logfile of HijackThis v1.99.1
Scan saved at 15:09:00, on 08/11/2008
Platform: Windows XP SP3 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16735)

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:\WINDOWS\Explorer.EXE
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe
C:\Program Files\Internet Explorer\IEXPLORE.EXE
C:\WINDOWS\system32\ctfmon.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Internet Explorer\Iexplore.exe
C:\WINDOWS\system32\wuauclt.exe
C:\WINDOWS\system32\wuauclt.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\ESTsoft\ALZip\ALZip.exe
C:\Documents and Settings\sylvain\My Documents\HiJackThis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.fr/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
R3 - URLSearchHook: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O3 - Toolbar: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [!AVG Anti-Spyware] "C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe" /minimized
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O11 - Options group: [INTERNATIONAL] International*
O16 - DPF: {30528230-99f7-4bb4-88d8-fa1d4f56a2ab} (YInstStarter Class) - C:\Program Files\Yahoo!\Common\yinsthelper.dll
O20 - Winlogon Notify: dimsntfy - %SystemRoot%\System32\dimsntfy.dll (file missing)
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 - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe" /service (file missing)
O23 - Service: avast! Web Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe" /service (file missing)
O23 - Service: AVG Anti-Spyware Guard - GRISOFT s.r.o. - C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe

Merci pour votre aide

Sylvain

Bonjour, je n'ai pas réussi à télécharger Catchme (le lien semble mort, et même dans Google, ce logiciel est introuvable); mais j'ai vu dans le forum quelqu'un qui a à peu près le même souci que moi, on lui a conseillé Malwarebyte's anti malware; je l'ai donc téléchargé et je vous poste le rapport que ce logiciel vient d'effectuer:
Malwarebytes' Anti-Malware 1.30
Version de la base de données: 1375
Windows 5.1.2600 Service Pack 3

09/11/2008 13:51:20
mbam-log-2008-11-09 (13-51-20).txt

Type de recherche: Examen rapide
Eléments examinés: 51219
Temps écoulé: 7 minute(s), 20 second(s)

Processus mémoire infecté(s): 0
Module(s) mémoire infecté(s): 0
Clé(s) du Registre infectée(s): 2
Valeur(s) du Registre infectée(s): 0
Elément(s) de données du Registre infecté(s): 2
Dossier(s) infecté(s): 5
Fichier(s) infecté(s): 7

Processus mémoire infecté(s):
(Aucun élément nuisible détecté)

Module(s) mémoire infecté(s):
(Aucun élément nuisible détecté)

Clé(s) du Registre infectée(s):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\tdssdata (Trojan.Agent) -> Quarantined and deleted successfully.
HKEY_LOCAL_MACHINE\SOFTWARE\tdss (Trojan.Agent) -> Quarantined and deleted successfully.

Valeur(s) du Registre infectée(s):
(Aucun élément nuisible détecté)

Elément(s) de données du Registre infecté(s):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Userinit (Trojan.Agent) -> Data: c:\windows\system32\ -> Quarantined and deleted successfully.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Userinit (Trojan.Agent) -> Data: system32\ -> Quarantined and deleted successfully.

Dossier(s) infecté(s):
C:\Documents and Settings\All Users\Application Data\Software Licensors\Antispyware PRO XP (Rogue.AntiSpywareProXP) -> Quarantined and deleted successfully.
C:\Documents and Settings\All Users\Application Data\Software Licensors\Antispyware PRO XP\BASE (Rogue.AntiSpywareProXP) -> Quarantined and deleted successfully.
C:\Documents and Settings\All Users\Application Data\Software Licensors\Antispyware PRO XP\DELETED (Rogue.AntiSpywareProXP) -> Quarantined and deleted successfully.
C:\Documents and Settings\All Users\Application Data\Software Licensors\Antispyware PRO XP\LOG (Rogue.AntiSpywareProXP) -> Quarantined and deleted successfully.
C:\Documents and Settings\All Users\Application Data\Software Licensors\Antispyware PRO XP\SAVED (Rogue.AntiSpywareProXP) -> Quarantined and deleted successfully.

Fichier(s) infecté(s):
C:\Documents and Settings\All Users\Application Data\Software Licensors\Antispyware PRO XP\LOG\20080909180333281.log (Rogue.AntiSpywareProXP) -> Quarantined and deleted successfully.
C:\Documents and Settings\All Users\Application Data\services\services.dll (Trojan.Agent) -> Quarantined and deleted successfully.
C:\WINDOWS\system32\56b1l84N.exe.a_a (Trojan.Agent) -> Quarantined and deleted successfully.
C:\WINDOWS\system32\y6NXGFv1.exe.a_a (Trojan.Agent) -> Quarantined and deleted successfully.
C:\WINDOWS\system32\ (Trojan.Agent) -> Quarantined and deleted successfully.
C:\WINDOWS\system32\drivers\ (Trojan.Agent) -> Quarantined and deleted successfully.
C:\WINDOWS\system32\drivers\svchost.exe (Heuristics.Reserved.Word.Exploit) -> Quarantined and deleted successfully.

Reposte un rapport Hijackthis.

Re,

Désinstalle correctement Avast! pour le remplacer par AntiVir.
Pourquoi changer ? Avast! vs AntiVir

Fais un scan complet puis poste le rapport en fin d'analyse.
AIDE : Tutorial sur l'antivirus AntiVir Personal Edition Classic

Bien, he vais faire ce que tu me conseille, il est vrai qu'Avast, sur ce coup là, a mal fait son boulot. mais j'ai une peur quand même: est ce qu'antivir ne va pas trop ralentir mon PC? Je vais quand meme faire le test.
Merci.

Bien, le scan a marché, il a repéré un Trojan que j'ai mis en quarantaine, voici le rapport d'antivir:

Avira AntiVir Personal
Report file date: Sunday, November 09, 2008 15:55

Scanning for 1019829 virus strains and unwanted programs.

Licensed to: Avira AntiVir PersonalEdition Classic
Serial number: 0000149996-ADJIE-0001
Platform: Windows XP
Windows version: (Service Pack 3) [5.1.2600]
Boot mode: Normally booted
Username: SYSTEM
Computer name: SISI-5FC49ABF46

Version information:
BUILD.DAT : 8.2.0.334 16933 Bytes 16/10/2008 14:55:00
AVSCAN.EXE : 8.1.4.7 315649 Bytes 26/06/2008 09:57:53
AVSCAN.DLL : 8.1.4.0 40705 Bytes 26/05/2008 08:56:40
LUKE.DLL : 8.1.4.5 164097 Bytes 12/06/2008 13:44:19
LUKERES.DLL : 8.1.4.0 12033 Bytes 26/05/2008 08:58:52
ANTIVIR0.VDF : 7.1.0.0 15603712 Bytes 27/10/2008 14:27:24
ANTIVIR1.VDF : 7.1.0.21 130560 Bytes 31/10/2008 14:27:25
ANTIVIR2.VDF : 7.1.0.44 139264 Bytes 06/11/2008 14:27:31
ANTIVIR3.VDF : 7.1.0.55 139776 Bytes 07/11/2008 14:27:33
Engineversion : 8.2.0.29
AEVDF.DLL : 8.1.0.6 102772 Bytes 14/10/2008 11:05:56
AESCRIPT.DLL : 8.1.1.13 332156 Bytes 09/11/2008 14:27:42
AESCN.DLL : 8.1.1.5 123251 Bytes 09/11/2008 14:27:41
AERDL.DLL : 8.1.1.3 438645 Bytes 09/11/2008 14:27:40
AEPACK.DLL : 8.1.3.3 393591 Bytes 09/11/2008 14:27:39
AEOFFICE.DLL : 8.1.0.30 196986 Bytes 09/11/2008 14:27:39
AEHEUR.DLL : 8.1.0.71 1487222 Bytes 09/11/2008 14:27:38
AEHELP.DLL : 8.1.1.3 119157 Bytes 09/11/2008 14:27:36
AEGEN.DLL : 8.1.1.0 319859 Bytes 09/11/2008 14:27:35
AEEMU.DLL : 8.1.0.9 393588 Bytes 14/10/2008 11:05:56
AECORE.DLL : 8.1.4.1 172405 Bytes 09/11/2008 14:27:34
AEBB.DLL : 8.1.0.3 53618 Bytes 14/10/2008 11:05:56
AVWINLL.DLL : 1.0.0.12 15105 Bytes 09/07/2008 09:40:05
AVPREF.DLL : 8.0.2.0 38657 Bytes 16/05/2008 10:28:01
AVREP.DLL : 8.0.0.2 98344 Bytes 09/11/2008 14:27:34
AVREG.DLL : 8.0.0.1 33537 Bytes 09/05/2008 12:26:40
AVARKT.DLL : 1.0.0.23 307457 Bytes 12/02/2008 09:29:23
AVEVTLOG.DLL : 8.0.0.16 119041 Bytes 12/06/2008 13:27:49
SQLITE3.DLL : 3.3.17.1 339968 Bytes 22/01/2008 18:28:02
SMTPLIB.DLL : 1.2.0.23 28929 Bytes 12/06/2008 13:49:40
NETNT.DLL : 8.0.0.1 7937 Bytes 25/01/2008 13:05:10
RCIMAGE.DLL : 8.0.0.51 2371841 Bytes 12/06/2008 14:48:07
RCTEXT.DLL : 8.0.52.0 86273 Bytes 27/06/2008 14:34:37

Configuration settings for the scan:
Jobname..........................: Complete system scan
Configuration file...............: c:\program files\avira\antivir personaledition classic\sysscan.avp
Logging..........................: low
Primary action...................: interactive
Secondary action.................: ignore
Scan master boot sector..........: on
Scan boot sector.................: on
Boot sectors.....................: C:, D:, H:,
Process scan.....................: on
Scan registry....................: on
Search for rootkits..............: off
Scan all files...................: Intelligent file selection
Scan archives....................: on
Recursion depth..................: 20
Smart extensions.................: on
Macro heuristic..................: on
File heuristic...................: medium

Start of the scan: Sunday, November 09, 2008 15:55

The scan of running processes will be started
Scan process 'avwsc.exe' - '1' Module(s) have been scanned
Scan process 'avscan.exe' - '1' Module(s) have been scanned
Scan process 'avscan.exe' - '1' Module(s) have been scanned
Scan process 'wuauclt.exe' - '1' Module(s) have been scanned
Scan process 'iexplore.exe' - '1' Module(s) have been scanned
Scan process 'wmiprvse.exe' - '1' Module(s) have been scanned
Scan process 'alg.exe' - '1' Module(s) have been scanned
Scan process 'wuauclt.exe' - '1' Module(s) have been scanned
Scan process 'avcenter.exe' - '1' Module(s) have been scanned
Scan process 'svchost.exe' - '1' Module(s) have been scanned
Scan process 'guard.exe' - '0' Module(s) have been scanned
Scan process 'avguard.exe' - '1' Module(s) have been scanned
Scan process 'msmsgs.exe' - '1' Module(s) have been scanned
Scan process 'ctfmon.exe' - '1' Module(s) have been scanned
Scan process 'avgnt.exe' - '1' Module(s) have been scanned
Scan process 'sched.exe' - '1' Module(s) have been scanned
Scan process 'spoolsv.exe' - '1' Module(s) have been scanned
Scan process 'explorer.exe' - '1' Module(s) have been scanned
Scan process 'svchost.exe' - '1' Module(s) have been scanned
Scan process 'svchost.exe' - '1' Module(s) have been scanned
Scan process 'svchost.exe' - '1' Module(s) have been scanned
Scan process 'svchost.exe' - '1' Module(s) have been scanned
Scan process 'svchost.exe' - '1' Module(s) have been scanned
Scan process 'lsass.exe' - '1' Module(s) have been scanned
Scan process 'services.exe' - '1' Module(s) have been scanned
Scan process 'winlogon.exe' - '1' Module(s) have been scanned
Scan process 'csrss.exe' - '1' Module(s) have been scanned
Scan process 'smss.exe' - '1' Module(s) have been scanned
27 processes with 27 modules were scanned

Starting master boot sector scan:
Master boot sector HD0
[INFO] No virus was found!
Master boot sector HD1
[INFO] No virus was found!

Start scanning boot sectors:
Boot sector 'C:\'
[INFO] No virus was found!
Boot sector 'D:\'
[INFO] No virus was found!
Boot sector 'H:\'
[INFO] No virus was found!

Starting to scan the registry.
The registry was scanned ( '43' files ).


Starting the file scan:

Begin scan in 'C:\' <New Volume>
C:\hiberfil.sys
[WARNING] The file could not be opened!
C:\pagefile.sys
[WARNING] The file could not be opened!
C:\Program Files\AdVantage\AdVUninst.exe
[DETECTION] Contains recognition pattern of the WORM/SaveNow.A.454096 worm
[NOTE] The file was moved to '496d1610.qua'!
C:\System Volume Information\_restore{713B0E39-B7E3-4191-ABC1-A3403515340D}\RP50\A0004046.exe
[0] Archive type: CAB SFX (self extracting)
--> \Setup\Data.Cab
[1] Archive type: CAB (Microsoft)
--> F5014_Lvkrn13n.dll.F437A828_B4A3_479C_925B_C77D3F4865CF
[WARNING] No further files can be extracted from this archive. The archive will be closed
--> \Setup\fra\Lisezmoi.html
[WARNING] No further files can be extracted from this archive. The archive will be closed
[WARNING] No further files can be extracted from this archive. The archive will be closed
Begin scan in 'D:\'
Begin scan in 'H:\'


End of the scan: Sunday, November 09, 2008 19:59
Used time: 4:04:06 Hour(s)

The scan has been done completely.

7621 Scanning directories
445225 Files were scanned
1 viruses and/or unwanted programs were found
0 Files were classified as suspicious:
0 files were deleted
0 files were repaired
1 files were moved to quarantine
0 files were renamed
3 Files cannot be scanned
445221 Files not concerned
3559 Archives were scanned
5 Warnings
1 Notes

Rebonjour,
J'ai fait tout ce que vous m'avez suggérer...
Les problèmes que j'avais sont partis maintenant, mais mon ordinateur rame un peu, les logiciels mettent beaucoup de temps à s'ouvrir.
voici le rapport Hijack:

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 20:03:42, on 11/11/2008
Platform: Windows XP SP3 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16735)
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:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Avira\AntiVir PersonalEdition Classic\sched.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Avira\AntiVir PersonalEdition Classic\avguard.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\wuauclt.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe
C:\Program Files\Avira\AntiVir PersonalEdition Classic\avgnt.exe
C:\WINDOWS\system32\taskmgr.exe
C:\PROGRA~1\MICROS~2\OFFICE11\OUTLOOK.EXE
C:\Program Files\Microsoft Office\OFFICE11\WINWORD.EXE
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Trend Micro\HijackThis\EDEN.exe

R3 - URLSearchHook: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O3 - Toolbar: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O4 - HKLM\..\Run: [KernelFaultCheck] %systemroot%\system32\dumprep 0 -k
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\Avira\AntiVir PersonalEdition Classic\avgnt.exe" /min
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows 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: Avira AntiVir Personal - Free Antivirus Scheduler (AntiVirScheduler) - Avira GmbH - C:\Program Files\Avira\AntiVir PersonalEdition Classic\sched.exe
O23 - Service: Avira AntiVir Personal - Free Antivirus Guard (AntiVirService) - Avira GmbH - C:\Program Files\Avira\AntiVir PersonalEdition Classic\avguard.exe
O23 - Service: AVG Anti-Spyware Guard - GRISOFT s.r.o. - C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe

--
End of file - 3020 bytes

Re,

Apparemment ok.

Bon surf.