Scaricando avventatamente un'applicazione .exe credo che avessi contratto un qualche virus, che fingeva di essere un antivirus (classico), e che come effetto collaterale, per rendere più realistica la cosa, aveva rilasciato altre infezioni all'interno del sistema.
In ogni caso mi aveva cambiato lo screensaver del desktop, bloccato internet, inibito l'accesso come amministratore... praticamente un incubo.

Seguendo alcuni consigli di un amico ho utilizzato Spyware Doctor per debellare l'infezione...
e poi ho fatto una serie di scansioni con vari antivirus per togliere quello che era rimasto (ed adesso il sistema sembra essere tornato a funzionare decentemente),
però vorrei essere sicura che non ci sia rimasto nulla di dannoso: quindi qualcuno potrebbe
dare un occhiata a questo report, per favore?

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 16.12.55, on 23/05/2010
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\csrss.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\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\Explorer.EXE
C:\Programmi\Spyware Doctor\pctsTray.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\ctfmon.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\Programmi\HP\Digital Imaging\bin\hpqtra08.exe
C:\WINDOWS\System32\svchost.exe
C:\PROGRA~1\AVG\AVG8\avgwdsvc.exe
C:\Programmi\Microsoft Office\Office12\ONENOTEM.EXE
C:\WINDOWS\System32\svchost.exe
C:\Programmi\Spyware Doctor\BDT\BDTUpdateService.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\PROGRA~1\AVG\AVG8\avgrsx.exe
C:\PROGRA~1\AVG\AVG8\avgnsx.exe
C:\WINDOWS\system32\svchost.exe
C:\Programmi\Java\jre6\bin\jqs.exe
C:\Programmi\File comuni\Microsoft Shared\VS7DEBUG\MDM.EXE
C:\WINDOWS\System32\svchost.exe
C:\Programmi\Telecom Italia\WanMiniport1st\srvany.exe
C:\WINDOWS\System32\svchost.exe
C:\Programmi\Telecom Italia\WanMiniport1st\WanMiniport1st_srv.exe
C:\Programmi\Spyware Doctor\pctsAuxs.exe
C:\Programmi\Spyware Doctor\pctsSvc.exe
C:\Programmi\Microsoft\Search Enhancement Pack\SeaPort\SeaPort.exe
C:\WINDOWS\System32\PAStiSvc.exe
C:\WINDOWS\system32\svchost.exe
C:\Programmi\Yahoo!\SoftwareUpdate\YahooAUService. exe
C:\PROGRA~1\AVG\AVG8\avgemc.exe
C:\Programmi\AVG\AVG8\avgcsrvx.exe
C:\Programmi\Windows Live\Messenger\msnmsgr.exe
C:\Programmi\HP\Digital Imaging\bin\hpqSTE08.exe
C:\Programmi\HP\Digital Imaging\bin\hpqbam08.exe
C:\Programmi\HP\Digital Imaging\bin\hpqgpc01.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\notepad.exe
C:\Programmi\Trend Micro\HijackThis\HijackThis.exe
C:\WINDOWS\system32\notepad.exe
C:\WINDOWS\system32\wbem\wmiprvse.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.it/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://toolbar.ask.com/toolbarv/askR...5&gct=&gc=1&q=
R1 - HKLM\Software\Microsoft\Internet Explorer\Search,Default_Search_URL = http://toolbar.ask.com/toolbarv/askR...5&gct=&gc=1&q=
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://toolbar.ask.com/toolbarv/askR...gct=&gc=1&q=%s
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Int ernet Settings,ProxyServer = http=127.0.0.1:5555
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
R3 - URLSearchHook: AVG Security Toolbar BHO - {A3BC75A2-1F87-4686-AA43-5347D756017C} - C:\Programmi\AVG\AVG8\Toolbar\IEToolbar.dll
R3 - URLSearchHook: (no name) - *{CFBFAE00-17A6-11D0-99CB-00C04FD64497} - (no file)
R3 - URLSearchHook: (no name) - *{C94E154B-1459-4A47-966B-4B843BEFC7DB} - (no file)
R3 - URLSearchHook: (no name) - *{EF99BD32-C1FB-11D2-892F-0090271D4F88} - (no file)
O2 - BHO: &Yahoo! Toolbar Helper - {02478D38-C3F9-4efb-9B51-7695ECA05670} - C:\Programmi\Yahoo!\Companion\Installs\cpn1\yt.dll
O2 - BHO: C:\WINDOWS\system32\c3say1.dll - {C7BA40A1-74F2-52BD-F411-04B15A2C8953} - C:\WINDOWS\system32\c3say1.dll (file missing)
O3 - Toolbar: Ask Toolbar - {3041d03e-fd4b-44e0-b742-2d9b88305f98} - C:\Programmi\AskBarDis\bar\bin\askBar.dll
O3 - Toolbar: AVG Security Toolbar - {CCC7A320-B3CA-4199-B1A6-9F516DD69829} - C:\Programmi\AVG\AVG8\Toolbar\IEToolbar.dll
O3 - Toolbar: Google Toolbar - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - C:\Programmi\Google\Google Toolbar\GoogleToolbar.dll
O3 - Toolbar: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Programmi\Yahoo!\Companion\Installs\cpn1\yt.dll
O3 - Toolbar: &Windows Live Toolbar - {21FA44EF-376D-4D53-9B0F-8A89D3229068} - C:\Programmi\Windows Live\Toolbar\wltcore.dll
O3 - Toolbar: PC Tools Browser Guard - {472734EA-242A-422B-ADF8-83D1E48CC825} - C:\Programmi\Spyware Doctor\BDT\PCTBrowserDefender.dll
O4 - HKLM\..\Run: [3544] C:\DOCUME~1\User\IMPOST~1\Temp\wnhqinrh.exe
O4 - HKLM\..\Run: [ISTray] "C:\Programmi\Spyware Doctor\pctsTray.exe"
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKLM\..\Policies\Explorer\Run: [rtw9ws] C:\DOCUME~1\User\IMPOST~1\Temp\jo2lej.exe
O4 - HKLM\..\Policies\Explorer\Run: [RTHDBPL] C:\DOCUME~1\User\IMPOST~1\Temp\16.tmp
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 - Startup: algeki32.exe
O4 - Startup: Ritaglio schermata e avvio di OneNote 2007.lnk = C:\Programmi\Microsoft Office\Office12\ONENOTEM.EXE
O4 - Global Startup: HP Digital Imaging Monitor.lnk = C:\Programmi\HP\Digital Imaging\bin\hpqtra08.exe
O8 - Extra context menu item: Add to Windows &Live Favorites - http://favorites.live.com/quickadd.aspx
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office12\EXCEL.EXE/3000
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: Invia a OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~1\MICROS~2\Office12\ONBttnIE.dll
O9 - Extra 'Tools' menuitem: I&nvia a OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~1\MICROS~2\Office12\ONBttnIE.dll
O9 - Extra button: (no name) - {5067A26B-1337-4436-8AFE-EE169C2DA79F} - C:\Programmi\Skype\Toolbars\Internet Explorer\SkypeIEPlugin.dll
O9 - Extra 'Tools' menuitem: Skype add-on for Internet Explorer - {5067A26B-1337-4436-8AFE-EE169C2DA79F} - C:\Programmi\Skype\Toolbars\Internet Explorer\SkypeIEPlugin.dll
O9 - Extra button: Skype - {77BF5300-1474-4EC7-9980-D32B190E9B07} - C:\Programmi\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: Selezione intelligente HP - {DDE87865-83C5-48c4-8357-2F5B1AA84522} - C:\Programmi\HP\Digital Imaging\Smart Web Printing\hpswp_BHO.dll
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe
O15 - Trusted Zone: http://*.digital-supply.com
O15 - Trusted Zone: http://*.download-soft-package.com
O15 - Trusted Zone: http://*.download-software-package.com
O15 - Trusted Zone: http://*.get-key-se10.com
O15 - Trusted Zone: http://*.is-software-download.com
O15 - Trusted Zone: http://*.digital-supply.com (HKLM)
O15 - Trusted Zone: http://*.get-key-se10.com (HKLM)
O18 - Protocol: grooveLocalGWS - {88FED34C-F0CA-4636-A375-3CB6248B04CD} - C:\PROGRA~1\MICROS~2\Office12\GR99D3~1.DLL
O18 - Protocol: linkscanner - {F274614C-63F8-47D5-A4D1-FBDDE494F8D1} - C:\Programmi\AVG\AVG8\avgpp.dll
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~1\FILECO~1\Skype\SKYPE4~1.DLL
O18 - Filter: x-sdch - {B1759355-3EEC-4C1E-B0F1-B719FE26E377} - C:\Programmi\Google\Google Toolbar\Component\fastsearch_A8904FB862BD9564.dll
O20 - Winlogon Notify: 343d083d923 - C:\WINDOWS\system32\comaddin32.dll
O20 - Winlogon Notify: avgrsstarter - C:\WINDOWS\SYSTEM32\avgrsstx.dll
O22 - SharedTaskScheduler: har98fefiesjfs93s8i9sejsdf - {C7BA40A1-74F2-52BD-F411-04B15A2C8953} - C:\WINDOWS\system32\c3say1.dll (file missing)
O23 - Service: AVG Free8 E-mail Scanner (avg8emc) - AVG Technologies CZ, s.r.o. - C:\PROGRA~1\AVG\AVG8\avgemc.exe
O23 - Service: AVG Free8 WatchDog (avg8wd) - AVG Technologies CZ, s.r.o. - C:\PROGRA~1\AVG\AVG8\avgwdsvc.exe
O23 - Service: Browser Defender Update Service - Threat Expert Ltd. - C:\Programmi\Spyware Doctor\BDT\BDTUpdateService.exe
O23 - Service: FLEXnet Licensing Service - Acresso Software Inc. - C:\Programmi\File comuni\Macrovision Shared\FLEXnet Publisher\FNPLicensingService.exe
O23 - Service: Servizio di Google Update (gupdate1cabed6ea9ebe92) (gupdate1cabed6ea9ebe92) - Google Inc. - C:\Programmi\Google\Update\GoogleUpdate.exe
O23 - Service: Google Software Updater (gusvc) - Google - C:\Programmi\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: Java Quick Starter (JavaQuickStarterService) - Sun Microsystems, Inc. - C:\Programmi\Java\jre6\bin\jqs.exe
O23 - Service: Network WanMiniport First Position - Unknown owner - C:\Programmi\Telecom Italia\WanMiniport1st\srvany.exe
O23 - Service: PC Tools Auxiliary Service (sdAuxService) - PC Tools - C:\Programmi\Spyware Doctor\pctsAuxs.exe
O23 - Service: PC Tools Security Service (sdCoreService) - PC Tools - C:\Programmi\Spyware Doctor\pctsSvc.exe
O23 - Service: STI Simulator - Unknown owner - C:\WINDOWS\System32\PAStiSvc.exe
O23 - Service: Yahoo! Updater (YahooAUService) - Yahoo! Inc. - C:\Programmi\Yahoo!\SoftwareUpdate\YahooAUService. exe

--
End of file - 9618 bytes