Spero qualcuno potrà aiutarmi.
Da due giorni mi compare un messaggio dalla pagina web (una finestrella grigia) che mi dice in questa sequenza:
WINDOWS INTERNET EXPLORER.
(Punto esclamativo all'interno di un pallino blu)
Uscire dalla pagina?
Messaggio dalla pagina web: false.
Esci dalla pagina.
Resta nella pagina.

Uso Windows 7 e Explorer 11.
Succede spesso su Ebay, quando clicco sul un qualsiasi altro link selezionando un oggetto.
Il messaggio compare prima di visualizzare la pagina cliccata. Se clicco su Resta nella pagina, non succede nulla.
Se clicco su Esci dalla pagina, vado nella pagina da me precedentemente cliccata, ma rimasta in stand by.
Può essere un virus?

Vi posto il log di Hijackthis:
Logfile of Trend Micro HijackThis v2.0.5
Scan saved at 18:35:35, on 20/03/2016
Platform: Windows 7 SP1 (WinNT 6.00.3505)
MSIE: Internet Explorer v11.0 (11.00.9600.18231)


Boot mode: Normal

Running processes:
C:\windows\system32\taskeng.exe
C:\windows\system32\Dwm.exe
C:\Program Files\Samsung\Samsung Recovery Solution 4\WCScheduler.exe
C:\windows\Explorer.EXE
C:\Program Files\Samsung\Easy Display Manager\dmhkcore.exe
C:\Program Files\SAMSUNG\EasySpeedUpManager\EasySpeedUpManager.exe
C:\Program Files\Samsung\Samsung Support Center\SSCKbdHk.exe
C:\windows\system32\taskhost.exe
C:\Program Files\Realtek\Audio\HDA\RtHDVCpl.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\windows\system32\igfxext.exe
C:\windows\system32\igfxsrvc.exe
C:\Program Files\AVAST Software\Avast\AvastUI.exe
C:\Program Files\Synaptics\SynTP\SynTPHelper.exe
C:\Windows\System32\igfxpers.exe
C:\windows\system32\wbem\unsecapp.exe
C:\windows\system32\wuauclt.exe
C:\PROGRA~1\samsung\SAMSUN~2\SUPNOT~1.EXE
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\windows\system32\Macromed\Flash\FlashUtil32_21_0_0_182_ActiveX.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\windows\System32\MsSpellCheckingFacility.exe
C:\windows\system32\NOTEPAD.EXE
C:\Users\peaceman\Desktop\HijackThis.exe
C:\windows\system32\SearchFilterHost.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.google.it/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/p/?LinkId=255141
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/p/?LinkId=255141
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
O2 - BHO: avast! Online Security - {8E5E2654-AD2D-48bf-AC2D-D17F00898D06} - C:\Program Files\AVAST Software\Avast\aswWebRepIE.dll
O2 - BHO: Guida per l'accesso a Windows Live - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O4 - HKLM\..\Run: [RtHDVCpl] C:\Program Files\Realtek\Audio\HDA\RtHDVCpl.exe -s
O4 - HKLM\..\Run: [SynTPEnh] %ProgramFiles%\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [AvastUI.exe] "C:\Program Files\AVAST Software\Avast\AvastUI.exe" /nogui
O4 - HKLM\..\Run: [Persistence] C:\windows\system32\igfxpers.exe
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~3\Office12\EXCEL.EXE/3000
O9 - Extra button: Inserisci blog - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: Inserisci &blog in Windows Live Writer - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra button: Invia a OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~1\MICROS~3\Office12\ONBttnIE.dll
O9 - Extra 'Tools' menuitem: I&nvia a OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~1\MICROS~3\Office12\ONBttnIE.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~3\Office12\REFIEBAR.DLL
O11 - Options group: [ACCELERATED_GRAPHICS] Accelerated graphics
O17 - HKLM\System\CCS\Services\Tcpip\..\{B5E9509A-5297-43D8-87EB-65E3B44F2BBE}: NameServer = 8.8.8.8,8.8.4.4
O23 - Service: Avast Antivirus (avast! Antivirus) - AVAST Software - C:\Program Files\AVAST Software\Avast\AvastSvc.exe
O23 - Service: Servizio Google Update (gupdate) (gupdate) - Google Inc. - C:\Program Files\Google\Update\GoogleUpdate.exe
O23 - Service: Servizio Google Update (gupdatem) (gupdatem) - Google Inc. - C:\Program Files\Google\Update\GoogleUpdate.exe
O23 - Service: MBAMService - Malwarebytes Corporation - C:\Program Files\Malwarebytes Anti-Malware\mbamservice.exe
O23 - Service: Cyberlink RichVideo Service(CRVS) (RichVideo) - Unknown owner - C:\Program Files\CyberLink\Shared files\RichVideo.exe
O23 - Service: Skype Updater (SkypeUpdate) - Skype Technologies - C:\Program Files\Skype\Updater\Updater.exe

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End of file - 4638 bytes

incomincia con questo
http://forum.aiutamici.com/yaf_postst96025_eliminare-pagine-pubblicitarie-e-porcherie-varie.aspx

Wow, sono proprio fortunello! Sono l'unico ad avere questo problema :-)