facendo una scansione mi ha dato i seguenti risultati:

Malwarebytes Anti-Malware 1.75.0.1300
www.malwarebytes.org

Versione database: v2014.01.09.09

Windows 7 Service Pack 1 x86 NTFS
Internet Explorer 10.0.9200.16750
Tasca Pane :: TASCAPANE-PC [amministratore]

09/01/2014 23:19:15
MBAM-log-2014-01-10 (00-50-35).txt

Tipo di scansione: Scansione completa (C:\|)
Opzioni di scansione attive: Memoria | Esecuzione automatica | Registro | File di sistema | Euristica/Extra | Euristica/Shuriken | PUP | PUM
Opzioni di scansione disattivate: P2P
Elementi esaminati: 337007
Tempo impiegato: 50 minuti, 39 secondi

Processi rilevati in memoria: 0
(non sono stati rilevati elementi nocivi)

Moduli di memoria rilevati: 0
(non sono stati rilevati elementi nocivi)

Chiavi di registro rilevate: 5
HKCR\TypeLib\{7F2F43AC-A6F0-4685-A6BD-6550C3836F91} (PUP.Optional.Squirrelweb.A) -> Nessuna azione intrapresa.
HKCR\Interface\{58BB7423-A9E3-47E0-9742-61E3BC3D5A18} (PUP.Optional.Squirrelweb.A) -> Nessuna azione intrapresa.
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SquirrelWeb (PUP.Optional.SquirrelWeb.A) -> Nessuna azione intrapresa.
HKCU\Software\SquirrelWeb (PUP.Optional.SquirrelWeb.A) -> Nessuna azione intrapresa.
HKLM\Software\SquirrelWeb (PUP.Optional.SquirrelWeb.A) -> Nessuna azione intrapresa.

Valori di registro rilevati: 0
(non sono stati rilevati elementi nocivi)

Voci rilevate nei dati di registro: 0
(non sono stati rilevati elementi nocivi)

Cartelle rilevate: 1
C:\Program Files\SquirrelWeb (PUP.Optional.SquirrelWeb.A) -> Nessuna azione intrapresa.

File rilevati: 13
C:\$Recycle.Bin\S-1-5-21-1227608380-2347549918-51477129-1000\$RV21SGP.exe (PUP.Riskware.Patcher) -> Nessuna azione intrapresa.
C:\$Recycle.Bin\S-1-5-21-1227608380-2347549918-51477129-1000\$R1KCP9X.194\FileMaker.Pro.13.Advanced.(13.0v1).Patch-MPT.zip (PUP.Riskware.Patcher) -> Nessuna azione intrapresa.
C:\Program Files\FileMaker\FileMaker Pro 13\filemaker.pro.13.advanced.(13.0v1)-MPT.exe (PUP.Riskware.Patcher) -> Nessuna azione intrapresa.
C:\Program Files\SquirrelWeb\SquirrelWebBHO.dll (PUP.Optional.Squirrelweb.A) -> Nessuna azione intrapresa.
C:\Program Files\SquirrelWeb\updateSquirrelWeb.exe (PUP.Optional.Squirrelweb.A) -> Nessuna azione intrapresa.
C:\Users\Tasca Pane\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\MDA3R9AC\Setup[1].exe (PUP.Optional.Squirrelweb.A) -> Nessuna azione intrapresa.
C:\Users\Tasca Pane\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\Y9OSANGH\SquirrelWebSetup[1].exe (PUP.Optional.Squirrelweb.A) -> Nessuna azione intrapresa.
C:\Users\Tasca Pane\AppData\Local\Temp\is-K0DK3.tmp\InstallManager.exe (PUP.Optional.InstallMonetizer.A) -> Nessuna azione intrapresa.
C:\Users\Tasca Pane\Desktop\ALITALIA\Filemaker 13\FileMaker.Pro.13.Advanced.13.0.1.194\FileMaker.Pro.13.Advanced.(13.0v1).Patch-MPT.zip (PUP.Riskware.Patcher) -> Nessuna azione intrapresa.
C:\Users\Tasca Pane\AppData\Roaming\Bubble Dock.boostrap.log (PUP.Optional.Bubbledock.A) -> Nessuna azione intrapresa.
C:\Program Files\SquirrelWeb\SquirrelWeb.ico (PUP.Optional.SquirrelWeb.A) -> Nessuna azione intrapresa.
C:\Program Files\SquirrelWeb\SquirrelWebUninstall.exe (PUP.Optional.SquirrelWeb.A) -> Nessuna azione intrapresa.
C:\Program Files\SquirrelWeb\updateSquirrelWeb.InstallState (PUP.Optional.SquirrelWeb.A) -> Nessuna azione intrapresa.

(fine)

Ripeto: tuttavia, almeno apparentemente, nessun malfunzionamento. Devo fare qualcosa?
Grazie, Giovanni

Dimenticavo di aggiungere il log di HijackThis

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 00:56:49, on 10/01/2014
Platform: Unknown Windows (WinNT 6.01.3505 SP1)
MSIE: Unable to get Internet Explorer version!
Boot mode: Normal

Running processes:
C:\Windows\system32\taskhost.exe
C:\Windows\system32\Dwm.exe
C:\Windows\Explorer.EXE
C:\Program Files\ATI Technologies\AMDUSB3DeviceDetector\nusb3mon.exe
C:\Program Files\Realtek\Audio\HDA\RtkNGUI.exe
C:\Program Files\Common Files\InstallShield\UpdateService\issch.exe
C:\Program Files\Common Files\Java\Java Update\jusched.exe
C:\Program Files\Avira\AntiVir Desktop\avgnt.exe
C:\Program Files\AMD Quick Stream\AppexAcceleratorUI.exe
C:\Program Files\Windows Sidebar\sidebar.exe
C:\Program Files\ATI Technologies\ATI.ACE\Core-Static\MOM.exe
C:\Program Files\ATI Technologies\ATI.ACE\Core-Static\CCC.exe
C:\Windows\system32\taskhost.exe
F:\a Programmi utilizzati\HijackThis\HijackThis.exe

R1 - HKCU\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 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = *.local
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
R3 - URLSearchHook: (no name) - {D8278076-BC68-4484-9233-6E7F1628B56C} - (no file)
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: Java(tm) Plug-In SSV Helper - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre7\bin\ssv.dll
O2 - BHO: Windows Live ID Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre7\bin\jp2ssv.dll
O4 - HKLM\..\Run: [AMD AVT] Cmd.exe /c start "AMD Accelerated Video Transcoding device initialization" /min "C:\Program Files\AMD AVT\bin\kdbsync.exe" aml
O4 - HKLM\..\Run: [StartCCC] "C:\Program Files\ATI Technologies\ATI.ACE\Core-Static\CLIStart.exe" MSRun
O4 - HKLM\..\Run: [NUSB3MON] "C:\Program Files\ATI Technologies\AMDUSB3DeviceDetector\nusb3mon.exe"
O4 - HKLM\..\Run: [RTHDVCPL] C:\Program Files\Realtek\Audio\HDA\RtkNGUI.exe -s
O4 - HKLM\..\Run: [ISUSScheduler] "C:\Program Files\Common Files\InstallShield\UpdateService\issch.exe" -start
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Common Files\Java\Java Update\jusched.exe"
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\Avira\AntiVir Desktop\avgnt.exe" /min
O4 - HKCU\..\Run: [AppEx Accelerator UI] C:\Program Files\AMD Quick Stream\AppexAcceleratorUI.exe -h
O4 - HKCU\..\Run: [OpAgent] "OpAgent.exe" /agent
O4 - HKCU\..\Run: [Sidebar] C:\Program Files\Windows Sidebar\sidebar.exe /autoRun
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'SERVIZIO LOCALE')
O4 - HKUS\S-1-5-19\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'SERVIZIO LOCALE')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'SERVIZIO DI RETE')
O4 - HKUS\S-1-5-20\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'SERVIZIO DI RETE')
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: Bonjour - {7F9DB11C-E358-4ca6-A83D-ACC663939424} - C:\Program Files\Bonjour\ExplorerPlugin.dll
O10 - Unknown file in Winsock LSP: c:\program files\common files\microsoft shared\windows live\wlidnsp.dll
O10 - Unknown file in Winsock LSP: c:\program files\common files\microsoft shared\windows live\wlidnsp.dll
O11 - Options group: [ACCELERATED_GRAPHICS] Accelerated graphics
O13 - Gopher Prefix:
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{A09F903F-7B42-4F16-9B5B-5F0699F6B1B2}: NameServer = 8.8.8.8,8.8.4.4
O17 - HKLM\System\CS1\Services\Tcpip\..\{A09F903F-7B42-4F16-9B5B-5F0699F6B1B2}: NameServer = 8.8.8.8,8.8.4.4
O17 - HKLM\System\CS2\Services\Tcpip\..\{A09F903F-7B42-4F16-9B5B-5F0699F6B1B2}: NameServer = 8.8.8.8,8.8.4.4
O23 - Service: Adobe Acrobat Update Service (AdobeARMservice) - Adobe Systems Incorporated - C:\Program Files\Common Files\Adobe\ARM\1.0\armsvc.exe
O23 - Service: Adobe Flash Player Update Service (AdobeFlashPlayerUpdateSvc) - Adobe Systems Incorporated - C:\Windows\system32\Macromed\Flash\FlashPlayerUpdateService.exe
O23 - Service: AMD External Events Utility - AMD - C:\Windows\system32\atiesrxx.exe
O23 - Service: AMD FUEL Service - Advanced Micro Devices, Inc. - C:\Program Files\ATI Technologies\ATI.ACE\Fuel\Fuel.Service.exe
O23 - Service: Avira Pianificatore (AntiVirSchedulerService) - Avira Operations GmbH & Co. KG - C:\Program Files\Avira\AntiVir Desktop\sched.exe
O23 - Service: Avira Real-Time Protection (AntiVirService) - Avira Operations GmbH & Co. KG - C:\Program Files\Avira\AntiVir Desktop\avguard.exe
O23 - Service: Bonjour Service - Apple Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: FABS - Helping agent for MAGIX media database (Fabs) - MAGIX AG - C:\Program Files\Common Files\MAGIX Services\Database\bin\FABS.exe
O23 - Service: Firebird Server - MAGIX Instance (FirebirdServerMAGIXInstance) - MAGIX® - C:\Program Files\Common Files\MAGIX Services\Database\bin\fbserver.exe
O23 - Service: FreemakeVideoCapture - Ellora Assets Corp. - C:\Program Files\Freemake\CaptureLib\CaptureLibService.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: Mozilla Maintenance Service (MozillaMaintenance) - Mozilla Foundation - C:\Program Files\Mozilla Maintenance Service\maintenanceservice.exe
O23 - Service: @C:\Program Files\Nero\Update\NASvc.exe,-200 (NAUpdate) - Nero AG - C:\Program Files\Nero\Update\NASvc.exe
O23 - Service: PandoraService (PanService) - Pandora.TV - C:\Program Files\PANDORA.TV\PanService\PandoraService.exe
O23 - Service: SolidConverterPDFReadSpool (SCPDFReadSpool) - Solid Documents, LLC - C:\Windows\Installer\MSI30B3.tmp

--
End of file - 6735 bytes

Ok, grazie,
Giovanni