Ho installato sul PC sia Google Earth (che però non uso quasi mai) che Chrome (anche se preferisco navigare con firefox). Ad ogni modo ecco il log di Hijackthis:

Logfile of Trend Micro HijackThis v2.0.4
Scan saved at 09:17:54, on 29/04/2011
Platform: Windows 7 (WinNT 6.00.3504)
MSIE: Internet Explorer v8.00 (8.00.7600.16766)
Boot mode: Normal

Running processes:
C:\Windows\system32\taskhost.exe
C:\Windows\system32\Dwm.exe
C:\Windows\Explorer.EXE
C:\Program Files\G Data\InternetSecurity\Firewall\GDFirewallTray.exe
C:\Program Files\G Data\InternetSecurity\AVKTray\AVKTray.exe
C:\Program Files\Logitech\Logitech WebCam Software\LWS.exe
C:\Program Files\Common Files\Java\Java Update\jusched.exe
C:\Program Files\Common Files\Logishrd\LQCVFX\COCIManager.exe
C:\Windows\system32\wuauclt.exe
C:\Windows\explorer.exe
M:\Trend Micro\HiJackThis\HiJackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://search.findeer.com/
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
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = *.local
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
O1 - Hosts: 74.208.10.249 gs.apple.com
O2 - BHO: G Data WebFilter Class - {0124123D-61B4-456f-AF86-78C53A0790C5} - C:\Program Files\G Data\InternetSecurity\Webfilter\AVKWebIE.dll
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: PowerOffer - {3543619C-D563-43f7-95EA-4DA7E1CC396A} - C:\Users\Public\Documents\PowerOffer\PowerOfferBHO.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: SkypeIEPluginBHO - {AE805869-2E5C-4ED4-8F7B-F1F7851A4497} - C:\Program Files\Skype\Toolbars\Internet Explorer\skypeieplugin.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre6\bin\jp2ssv.dll
O3 - Toolbar: G Data WebFilter - {0124123D-61B4-456f-AF86-78C53A0790C5} - C:\Program Files\G Data\InternetSecurity\Webfilter\AVKWebIE.dll
O4 - HKLM\..\Run: [GDFirewallTray] C:\Program Files\G Data\InternetSecurity\Firewall\GDFirewallTray.exe
O4 - HKLM\..\Run: [G DATA AntiVirus Trayapplication] C:\Program Files\G Data\InternetSecurity\AVKTray\AVKTray.exe
O4 - HKLM\..\Run: [LogitechQuickCamRibbon] "C:\Program Files\Logitech\Logitech WebCam Software\LWS.exe" /hide
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Common Files\Java\Java Update\jusched.exe"
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office12\EXCEL.EXE/3000
O8 - Extra context menu item: Scarica con Mipony - file://M:\MiPony\Browser\IEContext.htm
O9 - Extra button: Skype add-on for Internet Explorer - {898EA8C8-E7FF-479B-8935-AEC46303B9E5} - C:\Program Files\Skype\Toolbars\Internet Explorer\skypeieplugin.dll
O9 - Extra 'Tools' menuitem: Skype add-on for Internet Explorer - {898EA8C8-E7FF-479B-8935-AEC46303B9E5} - C:\Program Files\Skype\Toolbars\Internet Explorer\skypeieplugin.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\Office12\REFIEBAR.DLL
O9 - Extra button: PokerStars.it - {C4046502-6524-4d87-896C-878F57D1FF07} - C:\Program Files\PokerStars.IT\PokerStarsUpdate.exe
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
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/flashplayer/current/swflash.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{EC8A2FEE-5C13-4BBB-956F-8D9543AA2F95}: NameServer = 192.168.2.1
O18 - Protocol: skype-ie-addon-data - {91774881-D725-4E58-B298-07617B9B86A8} - C:\Program Files\Skype\Toolbars\Internet Explorer\skypeieplugin.dll
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~1\COMMON~1\Skype\SKYPE4~1.DLL
O23 - Service: Apple Mobile Device - Apple Inc. - C:\Program Files\Common Files\Apple\Mobile Device Support\AppleMobileDeviceService.exe
O23 - Service: G Data AntiVirus Proxy (AVKProxy) - G Data Software AG - C:\Program Files\Common Files\G DATA\AVKProxy\AVKProxy.exe
O23 - Service: G Data Scheduler (AVKService) - G Data Software AG - C:\Program Files\G Data\InternetSecurity\AVK\AVKService.exe
O23 - Service: G Data Guardiano del file system (AVKWCtl) - G Data Software AG - C:\Program Files\G Data\InternetSecurity\AVK\AVKWCtl.exe
O23 - Service: Servizio Bonjour (Bonjour Service) - Apple Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: G Data Personal Firewall (GDFwSvc) - G Data Software AG - C:\Program Files\G Data\InternetSecurity\Firewall\GDFwSvc.exe
O23 - Service: G Data Scanner (GDScan) - G Data Software AG - C:\Program Files\Common Files\G DATA\GDScan\GDScan.exe
O23 - Service: Servizio di 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: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: Intel(R) PROSet Monitoring Service - Intel Corporation - C:\Windows\system32\IProsetMonitor.exe
O23 - Service: Servizio iPod (iPod Service) - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: Process Monitor (LVPrcSrv) - Logitech Inc. - C:\Program Files\Common Files\LogiShrd\LVMVFM\LVPrcSrv.exe
O23 - Service: NMSAccess - Unknown owner - C:\Program Files\CDBurnerXP\NMSAccessU.exe
O23 - Service: NVIDIA Display Driver Service (nvsvc) - NVIDIA Corporation - C:\Windows\system32\nvvsvc.exe
O23 - Service: PnkBstrA - Unknown owner - C:\Windows\system32\PnkBstrA.exe
O23 - Service: Cyberlink RichVideo Service(CRVS) (RichVideo) - Unknown owner - C:\Program Files\Cyberlink\Shared files\RichVideo.exe
O23 - Service: Steam Client Service - Valve Corporation - C:\Program Files\Common Files\Steam\SteamService.exe

--
End of file - 6596 bytes

Grazie per la risposta, ho fixato la riga da te indicata.