Dos optimizer : virus tenace

Bonjour,
en lançant MSCONFIG j'ai trouvé ce truc bizarre : dos opimizer.pif, impossible à décocher du démarrage et que hijack this ne veut pas fixer. C'eqt quoi donc ? Quelqu'un peut-il lire mon hijack svp ? J'ai aussi deux lignes blanches dans smconfig que je n'avais jamais vu avant.

Logfile of HijackThis v1.99.1
Scan saved at 12:55:10, on 06/03/2008
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16608)

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\system32\ZoneLabs\vsmon.exe
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
C:\WINDOWS\eHome\ehRecvr.exe
C:\WINDOWS\eHome\ehSched.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Fichiers communs\LightScribe\LSSrvc.exe
C:\WINDOWS\system32\nvsvc32.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\Tablet.exe
C:\WINDOWS\system32\mqsvc.exe
C:\Program Files\Hewlett-Packard\Shared\hpqwmiex.exe
C:\WINDOWS\system32\mqtgsvc.exe
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\WINDOWS\system32\dllhost.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\WTablet\TabUserW.exe
C:\WINDOWS\system32\Tablet.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\MSN Messenger\msnmsgr.exe
C:\Program Files\BitTorrent_DNA\dna.exe
C:\Program Files\Windows Media Player\WMPNSCFG.exe
C:\Documents and Settings\mag\Menu Démarrer\Programmes\Démarrage\Dos Optimizer.pif
C:\Program Files\Macromedia\Dreamweaver 8\Dreamweaver.exe
C:\PROGRA~1\MOZILL~1\FIREFOX.EXE
C:\HijackThis\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = https://www.bing.com/?FORM=TOOLBR&cc=fr&toHttps=1&redig=4527FFF1C12746FC9EDB535C75E80ECC
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?FORM=TOOLBR&cc=fr&toHttps=1&redig=4527FFF1C12746FC9EDB535C75E80ECC
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = https://www.msn.com/fr-fr/?ocid=iehp
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.msn.com/fr-fr/?ocid=iehp
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = https://www.bing.com/?FORM=TOOLBR&cc=fr&toHttps=1&redig=4527FFF1C12746FC9EDB535C75E80ECC
R1 - HKCU\Software\Microsoft\Internet Connection Wizard,ShellNext = https://login.live.com/ppsecure/sha1auth.srf?lc=1036
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Windows Live Toolbar Helper - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\Windows Live Toolbar\msntb.dll
O3 - Toolbar: Windows Live Toolbar - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\Windows Live Toolbar\msntb.dll
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [ZoneAlarm Client] "C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe"
O4 - HKLM\..\Run: [!AVG Anti-Spyware] "C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe" /minimized
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [RecGuard] C:\Windows\SMINST\RecGuard.exe
O4 - HKLM\..\Run: [High Definition Audio Property Page Shortcut] CHDAudPropShortcut.exe
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [MSConfig] C:\WINDOWS\PCHealth\HelpCtr\Binaries\MSConfig.exe /auto
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\MSN Messenger\msnmsgr.exe" /background
O4 - HKCU\..\Run: [BitTorrent DNA] "C:\Program Files\BitTorrent_DNA\dna.exe"
O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.exe
O4 - Startup: Dos Optimizer.pif = ?
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Restrictions present
O8 - Extra context menu item: &Windows Live Search - res://C:\Program Files\Windows Live Toolbar\msntb.dll/search.htm
O8 - Extra context menu item: Add to Windows &Live Favorites - https://onedrive.live.com/?id=favorites
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~3\OFFICE11\EXCEL.EXE/3000
O8 - Extra context menu item: Ouvrir dans un nouvel onglet d'arrière-plan - res://C:\Program Files\Windows Live Toolbar\Components\fr-fr\msntabres.dll.mui/229?145024c0bb1c413b86ff6d1d6c5e8f85
O8 - Extra context menu item: Ouvrir dans un nouvel onglet de premier plan - res://C:\Program Files\Windows Live Toolbar\Components\fr-fr\msntabres.dll.mui/230?145024c0bb1c413b86ff6d1d6c5e8f85
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll
O9 - Extra button: (no name) - {85d1f590-48f4-11d9-9669-0800200c9a66} - %windir%\bdoscandel.exe (file missing)
O9 - Extra 'Tools' menuitem: Uninstall BitDefender Online Scanner v8 - {85d1f590-48f4-11d9-9669-0800200c9a66} - %windir%\bdoscandel.exe (file missing)
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~3\OFFICE11\REFIEBAR.DLL
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*
O14 - IERESET.INF: START_PAGE_URL=https://www.msn.com/fr-fr?cobrand=hp-notebook.msn.com&ocid=HPDHP&pc=HPNTDF
O16 - DPF: {2BC66F54-93A8-11D3-BEB6-00105AA9B6AE} (Symantec AntiVirus scanner) - http://security.symantec.com/sscv6/SharedContent/vc/bin/AvSniff.cab
O16 - DPF: {5D86DDB5-BDF9-441B-9E9E-D4730F4EE499} (BDSCANONLINE Control) - http://www.bitdefender.fr/scan_fr/scan8/oscan8.cab
O16 - DPF: {644E432F-49D3-41A1-8DD5-E099162EEEC5} (Symantec RuFSI Utility Class) - http://security.symantec.com/sscv6/SharedContent/common/bin/cabsa.cab
O16 - DPF: {67DABFBF-D0AB-41FA-9C46-CC0F21721616} (DivXBrowserPlugin Object) - http://download.divx.com/player/DivXBrowserPlugin.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{FDD1AF36-E5A2-43F1-A08A-CE0AE5F78A0A}: NameServer = 213.154.95.126 213.154.64.13
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~1\FICHIE~1\Skype\SKYPE4~1.DLL
O20 - Winlogon Notify: !SASWinLogon - C:\Program Files\SUPERAntiSpyware\SASWINLO.dll
O21 - SSODL: WPDShServiceObj - {AAA288BA-9A4C-45B0-95D7-94D524869DB5} - C:\WINDOWS\system32\WPDShServiceObj.dll
O23 - Service: AddFiltr - Hewlett-Packard Development Company, L.P. - C:\Program Files\Hewlett-Packard\HP Quick Launch Buttons\AddFiltr.exe
O23 - Service: Adobe LM Service - Adobe Systems - C:\Program Files\Fichiers communs\Adobe Systems Shared\Service\Adobelmsvc.exe
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: hpqwmiex - Hewlett-Packard Development Company, L.P. - C:\Program Files\Hewlett-Packard\Shared\hpqwmiex.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - c:\Program Files\Fichiers communs\InstallShield\Driver\1050\Intel 32\IDriverT.exe
O23 - Service: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - C:\Program Files\Fichiers communs\LightScribe\LSSrvc.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe
O23 - Service: TabletService - Wacom Technology, Corp. - C:\WINDOWS\system32\Tablet.exe
O23 - Service: TrueVector Internet Monitor (vsmon) - Zone Labs, LLC - C:\WINDOWS\system32\ZoneLabs\vsmon.exe

merci d'avance
ced.