avg mi ha segnalato un virus, ma non riesce ad eliminarlo si tratta di trojan horse agent 2JCS, vi posto anche un log di hjcthis nel caso potesse servire:

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 14.33.19, on 01/06/2009
Platform: Windows XP SP3 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16827)
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\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\PROGRA~1\AVG\AVG8\avgwdsvc.exe
C:\Programmi\Java\jre6\bin\jqs.exe
C:\Programmi\Sunbelt Software\Personal Firewall\kpf4ss.exe
C:\Programmi\File comuni\Microsoft Shared\VS7DEBUG\MDM.EXE
C:\PROGRA~1\AVG\AVG8\avgrsx.exe
C:\Programmi\File comuni\Nero\Nero BackItUp 4\NBService.exe
C:\Programmi\Sunbelt Software\Personal Firewall\kpf4gui.exe
C:\WINDOWS\system32\nvsvc32.exe
C:\WINDOWS\System32\PAStiSvc.exe
C:\WINDOWS\system32\svchost.exe
C:\PROGRA~1\AVG\AVG8\avgemc.exe
C:\Programmi\AVG\AVG8\avgcsrvx.exe
C:\WINDOWS\system32\wbem\wmiapsrv.exe
C:\Programmi\Sunbelt Software\Personal Firewall\kpf4gui.exe
C:\PROGRA~1\AVG\AVG8\avgtray.exe
C:\WINDOWS\RTHDCPL.EXE
C:\Programmi\Microsoft Office\Office12\GrooveMonitor.exe
C:\WINDOWS\system32\RUNDLL32.EXE
C:\Programmi\Java\jre6\bin\jusched.exe
C:\Program Files\D-Link\DSL-200\dslstat.exe
C:\Program Files\D-Link\DSL-200\dslagent.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Programmi\Windows Live\Messenger\msnmsgr.exe
C:\Programmi\Microsoft Encarta\Microsoft Encarta 2007 - Premium DVD\EDICT.EXE
C:\Programmi\Windows Live\Messenger\usnsvc.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_FATIBVE.EXE
C:\PROGRA~1\AVG\AVG8\avgnsx.exe
C:\WINDOWS\explorer.exe
C:\Programmi\eMule\eMule.exe
C:\Programmi\Lavasoft\Ad-Aware\AAWService.exe
C:\Programmi\Lavasoft\Ad-Aware\AAWTray.exe
C:\Programmi\Mozilla Firefox\firefox.exe
C:\Programmi\AVG\AVG8\avgcsrvx.exe
D:\PROGRAMMI\HIJACKTHIS\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.it/
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
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Internet Connection Wizard,ShellNext = http://go.microsoft.com/fwlink/?LinkId=74005
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Programmi\File comuni\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: WormRadar.com IESiteBlocker.NavFilter - {3CA2F312-6F6E-4B53-A66E-4E65E497C8C0} - C:\Programmi\AVG\AVG8\avgssie.dll
O2 - BHO: Spybot-S&D IE Protection - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: Groove GFS Browser Helper - {72853161-30C5-4D22-B7F9-0BBC1D38A37E} - C:\Programmi\Microsoft Office\Office12\GrooveShellExtensions.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Encarta Web Companion Oggetto helper - {955BE0B8-BC85-4CAF-856E-8E0D8B610560} - C:\Programmi\File comuni\Microsoft Shared\Encarta Web Companion\2007\ENCWCBAR.DLL
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Programmi\Java\jre6\bin\jp2ssv.dll
O2 - BHO: JQSIEStartDetectorImpl - {E7E6F031-17CE-4C07-BC86-EABFE594F69C} - C:\Programmi\Java\jre6\lib\deploy\jqs\ie\jqs_plugin.dll
O2 - BHO: EpsonToolBandKicker Class - {E99421FB-68DD-40F0-B4AC-B7027CAE2F1A} - C:\Programmi\EPSON\EPSON Web-To-Page\EPSON Web-To-Page.dll
O3 - Toolbar: EPSON Web-To-Page - {EE5D279F-081B-4404-994D-C6B60AAEBA6D} - C:\Programmi\EPSON\EPSON Web-To-Page\EPSON Web-To-Page.dll
O3 - Toolbar: Encarta Web Companion - {147D6308-0614-4112-89B1-31402F9B82C4} - C:\Programmi\File comuni\Microsoft Shared\Encarta Web Companion\2007\ENCWCBAR.DLL
O4 - HKLM\..\Run: [AVG8_TRAY] C:\PROGRA~1\AVG\AVG8\avgtray.exe
O4 - HKLM\..\Run: [RTHDCPL] RTHDCPL.EXE
O4 - HKLM\..\Run: [Alcmtr] ALCMTR.EXE
O4 - HKLM\..\Run: [EPSON Stylus DX5000 Series] C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_FATIBVE.EXE /FU "C:\WINDOWS\TEMP\E_SB1.tmp" /EF "HKLM"
O4 - HKLM\..\Run: [GrooveMonitor] "C:\Programmi\Microsoft Office\Office12\GrooveMonitor.exe"
O4 - HKLM\..\Run: [Ad-Watch] C:\Programmi\Lavasoft\Ad-Aware\AAWTray.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\Programmi\QuickTime\QTTask.exe" -atboottime
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [nwiz] nwiz.exe /install
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\WINDOWS\system32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Programmi\Java\jre6\bin\jusched.exe"
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Programmi\Adobe\Reader 9.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [DSLSTATEXE] C:\Program Files\D-Link\DSL-200\dslstat.exe icon
O4 - HKLM\..\Run: [DSLAGENTEXE] C:\Program Files\D-Link\DSL-200\dslagent.exe
O4 - HKLM\..\Run: [Automatico Automatico EPSON Stylus DX5000 Series su ANTONELLA su SARA] C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_FATIBVE.EXE /FU "C:\WINDOWS\TEMP\E_S1766.tmp" /EF "HKLM"
O4 - HKLM\..\Run: [Automatico EPSON Stylus DX5000 Series su SARA] C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_FATIBVE.EXE /FU "C:\WINDOWS\TEMP\E_S2E.tmp" /EF "HKLM"
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [msnmsgr] "C:\Programmi\Windows Live\Messenger\msnmsgr.exe" /background
O4 - HKCU\..\Run: [E07IXLRD_94921062] "C:\Programmi\Microsoft Encarta\Microsoft Encarta 2007 - Premium DVD\EDICT.EXE" -m
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 - S-1-5-18 Startup: D-Link Dial-Up PPP Connection.lnk = ? (User 'SYSTEM')
O4 - .DEFAULT Startup: D-Link Dial-Up PPP Connection.lnk = ? (User 'Default user')
O4 - Startup: D-Link Dial-Up PPP Connection.lnk = ?
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
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: Barra di ricerca di Encarta - {B205A35E-1FC4-4CE3-818B-899DBBB3388C} - C:\Programmi\File comuni\Microsoft Shared\Encarta Search Bar\ENCSBAR.DLL
O9 - Extra button: (no name) - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O9 - Extra 'Tools' menuitem: Spybot - Search & Destroy Configuration - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
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
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://www.update.microsoft.com/windowsupdate/v6/V5Controls/en/x86/client/wuweb_site.cab?1235325704140
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\..\{35F708AD-746B-4862-9AD9-37271FC32F86}: NameServer = 212.216.112.112,212.216.172.62
O18 - Protocol: grooveLocalGWS - {88FED34C-F0CA-4636-A375-3CB6248B04CD} - C:\Programmi\Microsoft Office\Office12\GrooveSystemServices.dll
O18 - Protocol: linkscanner - {F274614C-63F8-47D5-A4D1-FBDDE494F8D1} - C:\Programmi\AVG\AVG8\avgpp.dll
O20 - Winlogon Notify: avgrsstarter - C:\WINDOWS\SYSTEM32\avgrsstx.dll
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: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Programmi\File comuni\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: Java Quick Starter (JavaQuickStarterService) - Sun Microsystems, Inc. - C:\Programmi\Java\jre6\bin\jqs.exe
O23 - Service: Sunbelt Kerio Personal Firewall 4 (KPF4) - Sunbelt Software - C:\Programmi\Sunbelt Software\Personal Firewall\kpf4ss.exe
O23 - Service: Lavasoft Ad-Aware Service - Lavasoft - C:\Programmi\Lavasoft\Ad-Aware\AAWService.exe
O23 - Service: Nero BackItUp Scheduler 4.0 - Nero AG - C:\Programmi\File comuni\Nero\Nero BackItUp 4\NBService.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe
O23 - Service: STI Simulator - Unknown owner - C:\WINDOWS\System32\PAStiSvc.exe

--
End of file - 9766 bytes

O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file
questa voce e' inutile. Il log non mi sembra abbia problemi pero' aspettiamo qualche "aiutamici" piu' esperto di me.

con l'avg o con hiacthis?
grazie ad entrambi

questo è il percoso
"C:\WINDOWS\system32\logagent.exe";"Trojan horse Agent2.JCS";"Object is white-listed (critical/system file that should not be removed)"

Malwarebytes' Anti-Malware 1.37
Versione del database: 2212
Windows 5.1.2600 Service Pack 3

02/06/2009 11.50.45
mbam-log-2009-06-02 (11-50-45).txt

Tipo di scansione: Scansione completa (C:\|D:\|)
Elementi scansionati: 169736
Tempo trascorso: 33 minute(s), 4 second(s)

Processi delle memoria infetti: 0
Moduli della memoria infetti: 0
Chiavi di registro infette: 0
Valori di registro infetti: 0
Elementi dato del registro infetti: 0
Cartelle infette: 0
File infetti: 0

Processi delle memoria infetti:
(Nessun elemento malevolo rilevato)

Moduli della memoria infetti:
(Nessun elemento malevolo rilevato)

Chiavi di registro infette:
(Nessun elemento malevolo rilevato)

Valori di registro infetti:
(Nessun elemento malevolo rilevato)

Elementi dato del registro infetti:
(Nessun elemento malevolo rilevato)

Cartelle infette:
(Nessun elemento malevolo rilevato)

File infetti:
(Nessun elemento malevolo rilevato)

Ciao fai una scansione online con kaspersky su questo link,clicca su KASPERSKY ONLINE SCANNER,attendi che scarica il database delle definizioni e poi partira' la scansione.

http://www.kaspersky.com/virusscanner

Ciao lunanera-nera .
Quel file: C:\WINDOWS\system32\logagent.exe ha tutta l'aria di essere un file legittimo.
E precisamente di Windows Media Player:
http://www.processlibrary.com/it/directory/files/logagent/
http://ita.tallemu.com/oasis2/file/microsoft_corporation/windows_media_player_logagent/logagent_exe/17881
Per me è un falso positivo di AVG.

Ciao lunanera-nera .
Si, probabilmente si sono accorti anche quelli di AVG, che è un falso positivo, e hanno corretto il tiro.
Comunque se riscontri qualche problema, sono qui.
Ciao!