Per favore potete controllare il log?
Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 20.20.40, on 20/02/2008
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)
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\system32\spoolsv.exe
C:\WINDOWS\Explorer.EXE
C:\Programmi\Kaspersky Lab\Kaspersky Anti-Virus 6.0\avp.exe
C:\Programmi\File comuni\Microsoft Shared\VS7DEBUG\MDM.EXE
C:\WINDOWS\SOUNDMAN.EXE
C:\Programmi\File comuni\Ahead\Lib\NeroCheck.exe
C:\Programmi\Kaspersky Lab\Kaspersky Anti-Virus 6.0\avp.exe
C:\Programmi\MessengerPlus! 3\MsgPlus.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Programmi\File comuni\Ahead\Lib\NMBgMonitor.exe
C:\Programmi\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
C:\Documents and Settings\All Users.WINDOWS\Menu Avvio\Programmi\Esecuzione automatica\Update_0802_KB111616.exe
C:\Programmi\Internet Explorer\iexplore.exe
C:\Programmi\File comuni\Microsoft Shared\Windows Live\WLLoginProxy.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\ntvdm.exe
C:\Programmi\Internet Explorer\iexplore.exe
C:\Programmi\WinRAR\WinRAR.exe
C:\DOCUME~1\Vassallo\IMPOST~1\Temp\Rar$EX00.578\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.it/
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Programmi\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {2BF0EE6C-7291-4F0E-B244-D92B1D98B6DA} - C:\WINDOWS\system32\davclnth.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Guida per l'accesso a Windows Live - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Programmi\File comuni\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\programmi\google\googletoolbar1.dll
O2 - BHO: Google Toolbar Notifier BHO - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - C:\Programmi\Google\GoogleToolbarNotifier\2.0.301.7164\swg.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\programmi\google\googletoolbar1.dll
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [NeroFilterCheck] C:\Programmi\File comuni\Ahead\Lib\NeroCheck.exe
O4 - HKLM\..\Run: [AVP] "C:\Programmi\Kaspersky Lab\Kaspersky Anti-Virus 6.0\avp.exe"
O4 - HKLM\..\Run: [MessengerPlus3] "C:\Programmi\MessengerPlus! 3\MsgPlus.exe"
O4 - HKLM\..\Run: [WindowsHive] C:\WINDOWS\system32\rpcc.exe
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [BgMonitor_{79662E04-7C6C-4d9f-84C7-88D8A56B10AA}] "C:\Programmi\File comuni\Ahead\Lib\NMBgMonitor.exe"
O4 - HKCU\..\Run: [swg] C:\Programmi\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
O4 - HKUS\S-1-5-19\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SERVIZIO LOCALE')
O4 - HKUS\S-1-5-20\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SERVIZIO DI RETE')
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: Update_0802_KB111616.exe
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~1\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: Web Anti-Virus statistics - {1F460357-8A94-4D71-9CA3-AA4ACF32ED8E} - C:\Programmi\Kaspersky Lab\Kaspersky Anti-Virus 6.0\scieplugin.dll
O9 - Extra button: Inserisci blog - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Programmi\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: Inserisci &blog in Windows Live Writer - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Programmi\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe (file missing)
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe (file missing)
O16 - DPF: {20A60F0D-9AFA-4515-A0FD-83BD84642501} (Checkers Class) - http://messenger.zone.msn.com/binary/msgrchkr.cab56986.cab
O16 - DPF: {5C051655-FCD5-4969-9182-770EA5AA5565} (Solitaire Showdown Class) - http://messenger.zone.msn.com/binary/SolitaireShowdown.cab56986.cab
O16 - DPF: {5D6F45B3-9043-443D-A792-115447494D24} (UnoCtrl Class) - http://messenger.zone.msn.com/IT-IT/a-UNO1/GAME_UNO1.cab
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://www.update.microsoft.com/windowsupdate/v6/V5Controls/en/x86/client/wuweb_site.cab?1200865986906
O16 - DPF: {C3F79A2B-B9B4-4A66-B012-3EE46475B072} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsPAClient.cab56907.cab
O23 - Service: Kaspersky Anti-Virus 6.0 (AVP) - Kaspersky Lab - C:\Programmi\Kaspersky Lab\Kaspersky Anti-Virus 6.0\avp.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Programmi\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Programmi\File comuni\InstallShield\Driver\11\Intel 32\IDriverT.exe

--
End of file - 5448 bytes

Ho dato un'occhiata io e sembra ci siano diverse voci sospette. Potete indicarmi come procedere? Grazie

Ciao,
Chiudi HijackThis in una cartella a lui dedicata (possibilmente non sul desktop), altrimenti perdi i backup;

Disattiva il Ripristino configurazione di Sistema come qui descritto

avvia in modalità provvisoria come qui descritto

rendi visibili le cartelle nascoste ------ > procedura:
da Risorse del computer:
Strumenti >> Opzioni cartella >> visualizzazione;
metti la spunta su:
Visualizza file e cartelle nascoste;
togli la spunta da:
Nascondi file protetti del sistema(consigliato)


Avvia hijackthis, con tutte le applicazioni chiuse, premi su Do a system scan only , spunta ed elimina (fix checked) le seguenti righe:

---

O2 - BHO: (no name) - {2BF0EE6C-7291-4F0E-B244-D92B1D98B6DA} - C:\WINDOWS\system32\davclnth.dll
O4 - HKLM\..\Run: [WindowsHive] C:\WINDOWS\system32\rpcc.exe
O4 - Global Startup: Update_0802_KB111616.exe
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe (file missing)
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe (file missing)

---

Trova e cancella i file in rosso:
___________________________________________
C:\Programmi\File comuni\Ahead\Lib\NeroCheck.exe
C:\Documents and Settings\All Users.WINDOWS\Menu Avvio\Programmi\Esecuzione automatica\Update_0802_KB111616.exe
___________________________________________

Start >> Esegui. Scrivi (o copia e incolla) la stringa %temp%, clicca su Ok, cancella i file temp del tuo profilo;

Vai su Strumenti >> Opzioni Internet, elimina la cronologia, i files temporanei internet, i cookies;
svuota il cestino;

riavvia il computer normalmente.
Rifai un controllo col tuo antivirus e posta un log aggiiornato.

---