W32.HLLW.Gaobot.FL

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Discovered: January 06, 2004
Updated: February 13, 2007 12:15:50 PM
Type: Worm
Systems Affected: Windows



W32.HLLW.Gaobot.FL is a minor variant of W32.HLLW.Gaobot.FB that attempts to spread to network shares and allows access to an infected computer through an IRC channel.

The worm uses multiple vulnerabilities to spread, including:

W32.HLLW.Gaobot.FL is compressed with ASPack and Petite.

Antivirus Protection Dates

  • Initial Rapid Release version January 07, 2004
  • Latest Rapid Release version January 07, 2004
  • Initial Daily Certified version January 07, 2004
  • Latest Daily Certified version January 07, 2004
  • Initial Weekly Certified release date January 07, 2004

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Writeup By: Kevin Ha

Discovered: January 06, 2004
Updated: February 13, 2007 12:15:50 PM
Type: Worm
Systems Affected: Windows


When W32.HLLW.Gaobot.FL is executed, it performs the following actions:

  1. Copies itself as %System%\winsys32.exe.


    Note: %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).


  2. Adds the value:

    "Windows Networking" = "winsys32.exe"

    to the registry keys:
    • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
      RunServices
    • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

  3. Adds the keys:
    • HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\ntsys32
    • HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\Root\
      LEGACY_NTSYS32

  4. Registers itself as a service with the following attributes:
    • Service name: ntsys32
    • Display name: Windows Networking

  5. Opens a randomly chosen TCP port to connect to an attacker.

  6. Connects to a predefined IRC channel, using its own IRC client, and listens for the commands from an attacker.

  7. Allows an attacker to remotely control a compromised computer, allowing him or her to perform any of the following actions:
    • Manage the installation of the worm
    • Dynamically update the installed worm
    • Download and execute files
    • Steal system information
    • Send the worm to other IRC users
    • Add new accounts

  8. Remotely schedules a task to run the worm on a newly infected computer.

  9. Randomly calculates an IP address and performs a Distributed Denial of Service (DDoS) attack against targeted systems.

  10. Acts as a proxy server for direct attacks from another machine.

  11. Sends data to TCP port 135, which exploits the DCOM RPC vulnerability, or sends data to TCP port 445 to exploit the RPC locator vulnerability.

  12. Probes the following shares:
    • admin$
    • c$
    • d$
    • e$
    • print$

      using the following user names and passwords, as well as any user names found using NetUserEnum():

      Usernames:
    • student
    • teacher
    • database
    • mysql
    • OWNER
    • computer
    • admins
    • mary
    • owner
    • wwwadmin
    • root
    • OEM
    • qwer
    • asdf
    • win
    • temp
    • home
    • Dell
    • xyz
    • abc
    • aaa
    • Inviter
    • Gast
    • Guest
    • Test
    • server
    • user
    • Owner
    • administrador
    • Administrat
    • User
    • Standard
    • mgmt
    • Convidado
    • Default
    • administrator
    • admin
    • kanri-sha
    • kanri
    • Ospite
    • Verwalter
    • Administrador
    • Coordinatore
    • Administrateur

      Passwords:
    • pw
    • mypass
    • mypc
    • love
    • pwd
    • poiuytrewq
    • zxcvbnm
    • admin123
    • qwerty
    • red123
    • password123
    • abc123
    • qwertyuiop
    • secrets
    • homework
    • porn
    • baby
    • werty
    • box
    • mybox
    • school
    • work
    • metal
    • leet
    • pussy
    • vagina
    • mybaby
    • asdfghjkl
    • xxyyzz
    • private
    • test123
    • changeme
    • penis
    • kids
    • supersecret
    • superman
    • Login
    • xxx
    • zxcv
    • yxcv
    • secret
    • foobar
    • god
    • sex
    • pat
    • patrick
    • alpha
    • 007
    • 123abc
    • 1234qwer
    • 123123
    • 121212
    • 111111
    • 110
    • 2600
    • 2002
    • enable
    • godblessyou
    • ihavenopass
    • 123asd
    • super
    • Internet
    • 123qwe
    • sybase
    • oracle
    • abcd
    • passwd
    • pass
    • 88888888
    • 11111111
    • 00000000
    • 000000
    • 111
    • 54321
    • 654321
    • 123456789
    • 12345678
    • 1234567
    • 123456
    • 12345
    • 1234
    • 123
    • Password
    • password
    • Admin

  13. Copies itself to any systems it compromised using the exploits mentioned above.

  14. Drops Backdoor.Gaobot to the compromised network shares, and then executes it.

  15. Steals the CD keys of the following games:
    • Soldier of Fortune II - Double Helix
    • Neverwinter
    • Westwood\Nox
    • Tiberian Sun
    • Red Alert 2
    • Red Alert
    • Project IGI 2
    • Command & Conquer Generals
    • Battlefield 1942 Secret Weapons of WWII
    • Battlefield 1942 The Road to Rome
    • Battlefield 1942
    • Rainbow Six III RavenShield
    • Nascar Racing 2003
    • Nascar Racing 2002
    • NHL 2003
    • NHL 2002
    • FIFA 2003
    • FIFA 2002
    • Need For Speed Hot Pursuit 2
    • The Gladiators
    • Unreal Tournament 2003
    • Legends of Might and Magic
    • Counter-Strike
    • Half-Life

  16. Ends the following processes associated with antivirus and firewall software:
    • zonealarm.EXE
    • zapro.EXE
    • vsmon.EXE
    • vshwin32.EXE
    • vbcmserv.EXE
    • sbserv.EXE
    • rtvscan.EXE
    • rapapp.EXE
    • pcscan.EXE
    • pccwin97.EXE
    • pccntmon.EXE
    • pavproxy.EXE
    • nvsvc32.EXE
    • ntrtscan.EXE
    • npscheck.EXE
    • notstart.EXE
    • lockdown2000.EXE
    • iamserv.EXE
    • iamapp.EXE
    • gbpoll.EXE
    • gbmenu.EXE
    • fsmb32.EXE
    • fsma32.EXE
    • fsm32.EXE
    • fsgk32.EXE
    • fsav32.EXE
    • fsaa.EXE
    • fnrb32.EXE
    • fih32.EXE
    • fch32.EXE
    • fameh32.EXE
    • f-stopw.EXE
    • defscangui.EXE
    • defalert.EXE
    • cpd.EXE
    • cleaner3.EXE
    • cleaner.EXE
    • ccPxySvc.EXE
    • ccEvtMgr.EXE
    • ccApp.EXE
    • blackd.EXE
    • avpm.EXE
    • avkwctl9.EXE
    • avkservice.EXE
    • avkpop.EXE
    • apvxdwin.EXE
    • agentw.EXE
    • _AVPM.EXE
    • _AVPCC.EXE
    • _AVP32.EXE
    • ZONEALARM.EXE
    • ZONALM2601.EXE
    • ZAUINST.EXE
    • ZATUTOR.EXE
    • ZAPSETUP3001.EXE
    • ZAPRO.EXE
    • XPF202EN.EXE
    • WrCtrl.EXE
    • WrAdmin.EXE
    • WYVERNWORKSFIREWALL.EXE
    • WSBGATE.EXE
    • WRCTRL.EXE
    • WRADMIN.EXE
    • WNT.EXE
    • WINRECON.EXE
    • WIMMUN32.EXE
    • WHOSWATCHINGME.EXE
    • WGFE95.EXE
    • WFINDV32.EXE
    • WEBTRAP.EXE
    • WEBSCANX.EXE
    • WATCHDOG.EXE
    • W9X.EXE
    • W32DSM89.EXE
    • VetTray.EXE
    • Vet95.EXE
    • VbCons.EXE
    • VSWINPERSE.EXE
    • VSWINNTSE.EXE
    • VSWIN9XE.EXE
    • VSSTAT.EXE
    • VSMON.EXE
    • VSMAIN.EXE
    • VSISETUP.EXE
    • VSECOMR.EXE
    • VSCHED.EXE
    • VSCENU6.02D30.EXE
    • VSCAN40.EXE
    • VPTRAY.EXE
    • VPFW30S.EXE
    • VPC42.EXE
    • VPC32.EXE
    • VNPC3000.EXE
    • VNLAN300.EXE
    • VIRUSMDPERSONALFIREWALL.EXE
    • VIR-HELP.EXE
    • VFSETUP.EXE
    • VETTRAY.EXE
    • VET95.EXE
    • VET32.EXE
    • VCSETUP.EXE
    • VBWINNTW.EXE
    • VBWIN9X.EXE
    • VBUST.EXE
    • VBCONS.EXE
    • VBCMSERV.EXE
    • UPDATE.EXE
    • UNDOBOOT.EXE
    • TROJANTRAP3.EXE
    • TRJSETUP.EXE
    • TRJSCAN.EXE
    • TRACERT.EXE
    • TITANINXP.EXE
    • TITANIN.EXE
    • TGBOB.EXE
    • TFAK5.EXE
    • TFAK.EXE
    • TDS2-NT.EXE
    • TDS2-98.EXE
    • TDS-3.EXE
    • TCM.EXE
    • TCA.EXE
    • TC.EXE
    • TBSCAN.EXE
    • TAUMON.EXE
    • TASKMON.EXE
    • SymProxySvc.EXE
    • SweepNet.SWEEPSRV.SYS.SWNETSUP.EXE
    • Sphinx.EXE
    • SYSEDIT.EXE
    • SYMTRAY.EXE
    • SYMPROXYSVC.EXE
    • SWEEP95.EXE
    • SUPPORTER5.EXE
    • SUPFTRL.EXE
    • ST2.EXE
    • SS3EDIT.EXE
    • SPYXX.EXE
    • SPHINX.EXE
    • SPF.EXE
    • SOFI.EXE
    • SMC.EXE
    • SHN.EXE
    • SHELLSPYINSTALL.EXE
    • SH.EXE
    • SGSSFW32.EXE
    • SFC.EXE
    • SETUP_FLOWPROTECTOR_US.EXE
    • SETUPVAMEEVAL.EXE
    • SERV95.EXE
    • SD.EXE
    • SCRSCAN.EXE
    • SCANPM.EXE
    • SCAN95.EXE
    • SCAN32.EXE
    • SBSERV.EXE
    • SAFEWEB.EXE
    • RULAUNCH.EXE
    • RTVSCN95.EXE
    • RSHELL.EXE
    • RRGUARD.EXE
    • RESCUE32.EXE
    • RESCUE.EXE
    • REGEDT32.EXE
    • REGEDIT.EXE
    • REALMON.EXE
    • RAV8WIN32ENG.EXE
    • RAV7WIN.EXE
    • RAV7.EXE
    • QSERVER.EXE
    • QCONSOLE.EXE
    • PVIEW95.EXE
    • PURGE.EXE
    • PSPF.EXE
    • PROTECTX.EXE
    • PROPORT.EXE
    • PROGRAMAUDITOR.EXE
    • PROCEXPLORERV1.0.EXE
    • PROCESSMONITOR.EXE
    • PPVSTOP.EXE
    • PPTBC.EXE
    • PPINUPDT.EXE
    • PORTMONITOR.EXE
    • PORTDETECTIVE.EXE
    • POPSCAN.EXE
    • POPROXY.EXE
    • POP3TRAP.EXE
    • PLATIN.EXE
    • PINGSCAN.EXE
    • PFWADMIN.EXE
    • PF2.EXE
    • PERSWF.EXE
    • PERSFW.EXE
    • PERISCOPE.EXE
    • PDSETUP.EXE
    • PCIP10117_0.EXE
    • PCFWALLICON.EXE
    • PCDSETUP.EXE
    • PCCWIN98.EXE
    • PCCIOMON.EXE
    • PCC2K_76_1436.EXE
    • PCC2002S902.EXE
    • PAVW.EXE
    • PAVSCHED.EXE
    • PAVPROXY.EXE
    • PAVCL.EXE
    • PANIXK.EXE
    • PADMIN.EXE
    • OUTPOSTPROINSTALL.EXE
    • OUTPOSTINSTALL.EXE
    • OUTPOST.EXE
    • OSTRONET.EXE
    • Nupgrade.EXE
    • Nui.EXE
    • NeoWatchLog.EXE
    • Navw32.EXE
    • NWTOOL16.EXE
    • NWService.EXE
    • NWINST4.EXE
    • NVC95.EXE
    • NVARCH16.EXE
    • NTXconfig.EXE
    • NTVDM.EXE
    • NSCHED32.EXE
    • NPSSVC.EXE
    • NPROTECT.EXE
    • NPFMESSENGER.EXE
    • NPF40_TW_98_NT_ME_2K.EXE
    • NORTON_INTERNET_SECU_3.0_407.EXE
    • NORMIST.EXE
    • NOD32.EXE
    • NMAIN.EXE
    • NISUM.EXE
    • NISSERV.EXE
    • NETUTILS.EXE
    • NETSTAT.EXE
    • NETSPYHUNTER-1.2.EXE
    • NETSCANPRO.EXE
    • NETMON.EXE
    • NETINFO.EXE
    • NETARMOR.EXE
    • NEOMONITOR.EXE
    • NDD32.EXE
    • NCINST4.EXE
    • NC2000.EXE
    • NAVWNT.EXE
    • NAVW32.EXE
    • NAVSTUB.EXE
    • NAVNT.EXE
    • NAVLU32.EXE
    • NAVENGNAVEX15.NAVLU32.EXE
    • NAVDX.EXE
    • NAVAPW32.EXE
    • NAVAPSVC.EXE
    • NAVAP.navapsvc.EXE
    • NAV Auto-Protect.NAV80TRY.EXE
    • N32SCANW.EXE
    • Monitor.EXE
    • Mcshield.EXE
    • MWATCH.EXE
    • MU0311AD.EXE
    • MSSMMC32.EXE
    • MSINFO32.EXE
    • MSCONFIG.EXE
    • MRFLUX.EXE
    • MPFTRAY.EXE
    • MPFSERVICE.EXE
    • MPFAGENT.EXE
    • MOOLIVE.EXE
    • MONITOR.EXE
    • MINILOG.EXE
    • MGUI.EXE
    • MGHTML.EXE
    • MGAVRTE.EXE
    • MGAVRTCL.EXE
    • MFWENG3.02D30.EXE
    • MFW2EN.EXE
    • MCVSSHLD.EXE
    • MCVSRTE.EXE
    • MCUPDATE.EXE
    • MCTOOL.EXE
    • MCMNHDLR.EXE
    • MCAGENT.EXE
    • LUSPT.EXE
    • LUINIT.EXE
    • LUCOMSERVER.EXE
    • LUAU.EXE
    • LUALL.EXE
    • LSETUP.EXE
    • LOOKOUT.EXE
    • LOCKDOWN2000.EXE
    • LOCKDOWN.EXE
    • LOCALNET.EXE
    • LDSCAN.EXE
    • LDPROMENU.EXE
    • LDPRO.EXE
    • LDNETMON.EXE
    • KILLPROCESSSETUP161.EXE
    • KERIO-WRP-421-EN-WIN.EXE
    • KERIO-WRL-421-EN-WIN.EXE
    • KERIO-PF-213-EN-WIN.EXE
    • KAVPF.EXE
    • KAVPERS40ENG.EXE
    • KAVLITE40ENG.EXE
    • JEDI.EXE
    • JAMMER.EXE
    • ISRV95.EXE
    • IRIS.EXE
    • IPARMOR.EXE
    • IOMON98.EXE
    • IFW2000.EXE
    • IFACE.EXE
    • ICSUPPNT.EXE
    • ICSUPP95.EXE
    • ICMON.EXE
    • ICLOADNT.EXE
    • ICLOAD95.EXE
    • IBMAVSP.EXE
    • IBMASN.EXE
    • IAMSTATS.EXE
    • IAMSERV.EXE
    • IAMAPP.EXE
    • HWPE.EXE
    • HTLOG.EXE
    • HACKTRACERSETUP.EXE
    • GUARDDOG.EXE
    • GUARD.EXE
    • GENERICS.EXE
    • GBPOLL.EXE
    • GBMENU.EXE
    • FSAV95.EXE
    • FSAV530WTBYB.EXE
    • FSAV530STBYB.EXE
    • FSAV.EXE
    • FRW.EXE
    • FPROT.EXE
    • FP-WIN_TRIAL.EXE
    • FP-WIN.EXE
    • FLOWPROTECTOR.EXE
    • FIREWALL.EXE
    • FINDVIRU.EXE
    • FAST.EXE
    • F-STOPW.EXE
    • F-PROT95.EXE
    • F-PROT.EXE
    • F-AGNT95.EXE
    • EXPERT.EXE
    • EXE.AVXW.EXE
    • EXANTIVIRUS-CNET.EXE
    • EVPN.EXE
    • ETRUSTCIPE.EXE
    • ESPWATCH.EXE
    • ESCANV95.EXE
    • ESCANHNT.EXE
    • ESCANH95.EXE
    • ESAFE.EXE
    • ENT.EXE
    • EFPEADM.EXE
    • ECENGINE.EXE
    • DVP95_0.EXE
    • DVP95.EXE
    • DRWEB32.EXE
    • DRWATSON.EXE
    • DPFSETUP.EXE
    • DPF.EXE
    • DOORS.EXE
    • DEPUTY.EXE
    • DEFWATCH.EXE
    • Claw95cf.EXE
    • Claw95.EXE
    • CWNTDWMO.EXE
    • CWNB181.EXE
    • CV.EXE
    • CTRL.EXE
    • CPFNT206.EXE
    • CPF9X206.EXE
    • CPD.EXE
    • CONNECTIONMONITOR.EXE
    • CMON016.EXE
    • CMGRDIAN.EXE
    • CLEANPC.EXE
    • CLEANER3.EXE
    • CLEANER.EXE
    • CLEAN.EXE
    • CLAW95CF.EXE
    • CFINET32.EXE
    • CFINET.EXE
    • CFIAUDIT.EXE
    • CFIADMIN.EXE
    • CFGWIZ.EXE
    • CDP.EXE
    • BlackICE.EXE
    • BS120.EXE
    • BORG2.EXE
    • BOOTWARN.EXE
    • BLACKICE.EXE
    • BLACKD.EXE
    • BISP.EXE
    • BIPCPEVALSETUP.EXE
    • BIPCP.EXE
    • BIDSERVER.EXE
    • BIDEF.EXE
    • BD_PROFESSIONAL.EXE
    • Avsched32.EXE
    • AvkServ.EXE
    • Avgctrl.EXE
    • AvgServ.EXE
    • AvSynMgr.AVSYNMGR.EXE
    • AutoTrace.EXE
    • AckWin32.EXE
    • AVXQUAR.EXE
    • AVXMONITORNT.EXE
    • AVXMONITOR9X.EXE
    • AVWUPSRV.EXE
    • AVWUPD32.EXE
    • AVWINNT.EXE
    • AVWIN95.EXE
    • AVPUPD.EXE
    • AVPTC32.EXE
    • AVPM.EXE
    • AVPDOS32.EXE
    • AVPCC.EXE
    • AVP32.EXE
    • AVP.EXE
    • AVNT.EXE
    • AVGW.EXE
    • AVGUARD.EXE
    • AVGSERV9.EXE
    • AVGSERV.EXE
    • AVGNT.EXE
    • AVGCTRL.EXE
    • AVGCC32.EXE
    • AVE32.EXE
    • AVCONSOL.EXE
    • AUTOUPDATE.EXE
    • AUTODOWN.EXE
    • AUPDATE.EXE
    • ATWATCH.EXE
    • ATUPDATER.EXE
    • ATRO55EN.EXE
    • ATGUARD.EXE
    • ATCON.EXE
    • APVXDWIN.EXE
    • APLICA32.EXE
    • APIMONITOR.EXE
    • ANTS.EXE
    • ANTIVIRUS.EXE
    • ANTI-TROJAN.EXE
    • AMON9X.EXE
    • ALOGSERV.EXE
    • ALERTSVC.EXE
    • AGENTSVR.EXE
    • ADVXDWIN.EXE
    • ACKWIN32.EXE

  17. Attempts to kill some processes associated with other worms:
    • winhlpp32.exe
    • tftpd.exe
    • dllhost.exe
    • winppr32.exe
    • mspatch.exe
    • penis32.exe
    • msblast.exe

  18. Listens on randomly calculated ports (within the range of 1000, and one from above 10000) and waits for other computers to download the worm.


Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.

Writeup By: Kevin Ha

Discovered: January 06, 2004
Updated: February 13, 2007 12:15:50 PM
Type: Worm
Systems Affected: Windows


The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

  1. Disable System Restore (Windows Me/XP).
  2. Update the virus definitions.
  3. Restart the computer in Safe mode or VGA mode.
  4. Find and stop the service.
  5. Run a full system scan and delete all the files detected as W32.HLLW.Gaobot.FL.
  6. Reverse the changes made to the registry.
For details on each of these steps, read the following instructions.

1. Disabling System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.

Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.

Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.

For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:
Note: When you are completely finished with the removal procedure and are satisfied that the threat has been removed, re-enable System Restore by following the instructions in the aforementioned documents.

For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article, "Antivirus Tools Cannot Clean Infected Files in the _Restore Folder," Article ID: Q263455.

2. Updating the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:

  • Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
  • Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).

    The Intelligent Updater virus definitions are available: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

3. Restarting the computer in Safe mode or VGA mode

Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode or VGA mode.
  • For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
  • For Windows NT 4 users, restart the computer in VGA mode.
4. Finding and stopping the service
  1. Click Start, and then click Run.
  2. Type services.msc, and then click OK.
  3. Locate and select the service detected as W32.HLLW.Gaobot.FL.
  4. Click Action, and then click Properties.
  5. Click Stop.
  6. Change Startup Type to Manual.
  7. Click OK and close the Services window.
  8. Restart the computer

5. Scanning for and deleting the infected files
  1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
  2. Run a full system scan.
  3. If any files are detected as infected with W32.HLLW.Gaobot.FL, click Delete.

6. Reversing the changes made to the registry


WARNING: Symantec strongly recommends that you back up the registry before making any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. Read the document, "How to make a backup of the Windows registry ," for instructions.
  1. Click Start, and then click Run. (The Run dialog box appears.)
  2. Type regedit

    Then click OK. (The Registry Editor opens.)

  3. Navigate to the key:
    • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
      RunServices
    • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
      Run

  4. In the right pane, delete the value:

    "Windows Networking" = "winsys32.exe"

  5. Delete the keys:

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\ntsys32
    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\Root\
    LEGACY_NTSYS32

  6. Exit the Registry Editor.


Writeup By: Kevin Ha