W32.Ahker.B@mm

Printer Friendly Page

Discovered: January 26, 2005
Updated: February 13, 2007 12:32:05 PM
Also Known As: Win32.Ahker.B [Computer Associ, Email-Worm.Win32.Anker.a [Kasp, W32/Ahker-B [Sophos]WORM_AHKER
Type: Worm
Systems Affected: Windows


W32.Ahker.B@mm is a mass-mailing worm that sends itself to all addresses in the Windows Address Book. The worm also disables several Widnows security features and disables the Start->Run feature, as well as preventing the task manager, registry editor, and notepad from running.

This threat is written in Visual Basic.



Removing entries from the Hosts file
If this threat has modified the Windows Hosts file, there are two ways to remove these entries:

  • Install and run the current version of LiveUpdate. This will remove only the entries that refer to Symantec domains.
  • Manually edit the Hosts file and remove all the entries that the worm added.

To run the current version of LiveUpdate
  1. Click download LiveUpdate.

    Note:
    If you are not reading this Web page on the computer that is getting the error notice, the address for downloading the file is:

    ftp://ftp.symantec.com/public/english_us_canada/liveupdate/lusetup.exe

    If necessary, you can type this address into the address bar of the problem computer. Changes to the Hosts file will not stop you from getting to this site.

  2. Save the file to the Windows desktop.
  3. Double-click the lusetup.exe icon on the desktop to install LiveUpdate.
  4. Run LiveUpdate.
  5. Did you see the message "LU1860: LiveUpdate has detected a potential security compromise on your computer"?
    • If you did, let LiveUpdate "Remove these entries from the hosts files" (Recommended).
      This should allow LiveUpdate to run.
    • If you did not, that was not the cause of the problem. Return to the Removal section.


To manually edit the Hosts file and remove all the entries that the worm added

Note: The location of the Hosts file may vary and some computers may not have this file. For example, if the file exists in Windows 98, it will usually be in C:\Windows; and it is located in the C:\WINNT\system32\drivers\etc folder in Windows 2000. There may also be multiple copies of this file in different locations.


Follow the instructions for your operating system:
  • Windows 95/98/Me/NT/2000
    1. Click Start, point to Find or Search, and then click Files or Folders.
    2. Make sure that "Look in" is set to (C:) and that "Include subfolders" is checked.
    3. In the "Named" or "Search for..." box, type:

      hosts

    4. Click Find Now or Search Now.
    5. For each Hosts file that you find, right-click the file, and then click Open With.
    6. Deselect the "Always use this program to open this program" check box.
    7. Scroll through the list of programs and double-click Notepad.
    8. When the file opens, delete all the entries in Step 15 of the "Technical Details" section.
    9. Close Notepad and save your changes when prompted.

  • Windows XP
    1. Click Start > Search.
    2. Click All files and folders.
    3. In the "All or part of the file name" box, type:

      hosts

    4. Verify that "Look in" is set to "Local Hard Drives" or to (C:).
    5. Click More advanced options.
    6. Check Search system folders.
    7. Check Search subfolders.
    8. Click Search.
    9. Click Find Now or Search Now.
    10. For each Hosts file that you find, right-click the file, and then click Open With.
    11. Deselect the Always use this program to open this program check box.
    12. Scroll through the list of programs and double-click Notepad.
    13. When the file opens, delete all the entries in Step 15 of the "Technical Details" section.
    14. Close Notepad and save your changes when prompted.


Antivirus Protection Dates

  • Initial Rapid Release version January 26, 2005
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version January 26, 2005
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date January 26, 2005

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

Writeup By: Rodney Andres

Discovered: January 26, 2005
Updated: February 13, 2007 12:32:05 PM
Also Known As: Win32.Ahker.B [Computer Associ, Email-Worm.Win32.Anker.a [Kasp, W32/Ahker-B [Sophos]WORM_AHKER
Type: Worm
Systems Affected: Windows


When W32.Ahker.B@mm is executed, it does the following:

  1. Creates the following copies of itself:

    • %Windir%\SERVICES.exe
    • %User Profile%\Start Menu\Programs\Startup\SERVICES.exe

      Notes:
    • %Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows or C:\Winnt.
    • %UserProfile% is a variable that refers to the current user's profile folder. By default, this is C:\Documents and Settings\<Current User> (Windows NT/2000/XP).

  2. Creates C:\Norton Antivirus.txt, which is a harmless text file.

  3. Adds the value:

    "Norton Auto-Protect" = "SERVICES.exe"

    to the registry subkey:

    HKEY_LOCAL_MACHINE\Software\Microsoft\windows\CurrentVersion\Run

    so that the worm runs when Windows starts.

  4. Adds the value:

    "[default]" = "SERVICES.EXE %1"

    to the registry subkeys:

    HKEY_CLASSES_ROOT\txtfile\shell\open\command
    HKEY_LOCAL_MACHINE\txtfile\shell\open\command

    so that the worm runs when the user attempts to open a .txt file.

  5. Adds the values:

    "DisableTaskMgr" = "dword:00000001"
    "DisableRegistryTools" = "dword:00000001"

    to the registry subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
    Policies\System

    to disable the Task Manager.

  6. Adds the values:

    "NoRun" = "dword:00000001"
    "DisallowRun" = "1"

    to the registry subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
    Policies\Explorer

  7. Adds the values:

    "1" = "regedit.exe"
    "2" = "notepad.exe"
    "3" = "wordpad.exe"
    "4" = "write.exe"
    "5" = "wuauclt.exe"
    "6" = "wupdmgr.exe"
    "7" = "%Program Files%\MSN Messenger\msnmsgr.exe"

    to the registry subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
    Policies\Explorer\DisallowRun

    so that the following programs are terminated:

    • Task Manager
    • Registry Editor
    • Notepad
    • Wordpad
    • Windows Update
    • MSN Messenger

  8. Adds the value:

    "DisableSR" = "dword:00000001"

    to the registry subkeys:

    HKEY_LOCAL_MACHINE\Software\Microsoft\windows NT\CurrentVersion\
    systemrestore
    HKEY_CURRENT_USER\Software\Microsoft\windows NT\CurrentVersion\
    systemrestore

    to disable some Windows security features.

  9. Adds the value:

    "NoAutoUpdate" = "dword:00000001"

    to the registry subkeys:

    HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\
    WindowsUpdate\AU
    HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\
    WindowsUpdate\AU

    to disable some Windows security features.

  10. Adds the value:

    "UpdatesDisableNotify" = "dword:00000001"

    to the registry subkeys:

    HKEY_LOCAL_MACHINE\Software\Microsoft\security center
    HKEY_CURRENT_USER\Software\Microsoft\security center

    to disable some Windows security features.

  11. Adds the value:

    "FirewallDisableNotify" = "dword:00000001"

    to the registry subkeys:

    HKEY_LOCAL_MACHINE\Software\Microsoft\security center
    HKEY_CURRENT_USER\Software\Microsoft\security center

    to disable some Windows security features.

  12. Adds the value:

    "AntiVirusDisableNotify" = "dword:00000001"

    to the registry subkeys:

    HKEY_LOCAL_MACHINE\Software\Microsoft\security center
    HKEY_CURRENT_USER\Software\Microsoft\security center

    to disable some Windows security features.

  13. Creates the following additional registry entries:

    HKEY_CLASSES_ROOT\RDP.File\"Friendlytypename" = "@SERVICES.exe, -4004"
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\RDP.File\"Friendlytypename" = "@SERVICES.exe, -4004"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\windows\CurrentVersion\
    app paths\LUALL.exe\[default] = "SERVICES.exe"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\windows\CurrentVersion\
    runservices-\"Windows Service" = "SERVICES.exe"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\windows\CurrentVersion\
    windowsupdate\auto update\[default] = "SERVICES.exe"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    Agent Hacker\[default] = "W32.Ahker.B@mm"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    Agent Hacker\"Version" = "B"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    Agent Hacker\"Coded In" = "Visual Basic 6.0"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    Agent Hacker\"Coded By = "Agent Hacker"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    Agent Hacker\"Spread" = "VIA Outlook"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    Agent Hacker\"Exploit" = "Symantec Norton Antivirus Script Blocker Denial Of Service Vulnerability"
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ComputerName\
    ActiveComputerName\ComputerName = "Agent Hacker"
    HKEY_LOCAL_MACHINE\software\Microsoft\Windows NT\CurrentVersion\
    "ProductId" = "Agent Hacker"
    HKEY_LOCAL_MACHINE\system\wpa\Key-MGM9K8XQ2GHRBGTP2TR93\
    "ProductID" = "Agent Hacker"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Registration\
    ProductID = "Agent Hacker"

  14. Terminates a series of processes including several related to antivirus and security applications. For a complete list, read the Processes section at the bottom of Technical Details.

  15. Adds the following lines to the hosts file to prevent access to certain Web sites:

    127.0.0.1 www.symantec.com
    127.0.0.1 www.microsoft.com
    127.0.0.1 www.wwe.com
    127.0.0.1 www.rohitab.com
    127.0.0.1 www.coderheaven.com
    127.0.0.1 www.astalavista.com
    127.0.0.1 www.google.com
    127.0.0.1 www.yahoo.com
    127.0.0.1 www.msn.com
    127.0.0.1 www.messenger.msn.com
    127.0.0.1 www.geocities.com
    127.0.0.1 www.worldsex.com
    127.0.0.1 www.cnn.com
    127.0.0.1 www.gamerevolution.com
    127.0.0.1 www.hackers.com
    127.0.0.1 www.fbi.gov
    127.0.0.1 www.hotmail.com
    127.0.0.1 www.norton.com
    127.0.0.1 www.idm.com

  16. Downloads the file ahkerb.zip from the geocities.com domain and saves it as C:\Fix_SP2.zip. The archive contains a copy of the worm.

  17. Uses MAPI to send email to all addresses in the Windows Address Book.

    The email has the following properties:

    Subject: Service Pack 2 BUG!!

    Message Body:
    Dear user I have been informed that there was a BUG in Windows Service Pack 2 which was fixed I recommend you to download this Patch version which will fix the bug and keep your system safe.
    You will find the Patch file in the attachment, feal free to send it to anyone.
    I'll be in touch with you as soon as another bug is found.
    Regards,
    A.H

    Attachment: Fix_SP2.zip

  18. Deletes C:\Fix_SP2.zip, once the email has been sent.

  19. Terminates the following processes:

    • SVCHOST.exe
    • LSASS.exe

Processes

The worm ends the following processes, including several related to antivirus and security applications, as described in step 8:

    • _Avpcc.exe
    • _avpm.exe
    • _findviru.exe
    • Ackwin32.exe
    • AGENTSVR.exe
    • Alogserv.exe
    • Amon.exe
    • Anti-trojan.exe
    • ANTIVIRUS.exe
    • ANTS.EXE
    • APIMONITOR.EXE
    • APLICA32.EXE
    • Apvxdwin.exe
    • ATCON.EXE
    • Atguard.exe
    • ATRO55EN.EXE
    • ATUPDATER
    • ATUPDATER.exe
    • ATWATCH.EXE
    • Au.exe
    • AUPDATE.exe
    • AUTODOWN.exe
    • AUTOTRACE.exe
    • AUTOUPDATE.exe
    • AVCONSOL.EXE
    • Ave32.exe
    • AVGSERV9.EXE
    • Avkserv.exe
    • AVLTMAIN.exe
    • Avnt.exe
    • Avpcc.exe
    • Avpm.exe
    • AVprotect9x.exe
    • AVPUPD.exe
    • avserve2.exe
    • AVSYNMGR.EXE
    • Avwin95.exe
    • AVWUPD32.exe
    • AVXQUAR.exe
    • BD_PROFESSIONAL.EXE
    • BIDEF.EXE
    • BIDSERVER.EXE
    • BIPCP.EXE
    • BIPCPEVALSETUP.EXE
    • BISP.EXE
    • BLACKD.EXE
    • BlackIce.exe
    • BOOTWARN.EXE
    • BORG2.EXE
    • BS120.EXE
    • ccApp.exe
    • CDP.EXE
    • CFGWIZ.EXE
    • CFIADMIN.EXE
    • CFIAUDIT.exe
    • CFINET.EXE
    • CFINET32.EXE
    • Claw95cf.exe
    • CLEAN.EXE
    • CLEANER.EXE
    • CLEANER3.EXE
    • CLEANPC.EXE
    • Cmgrdian.exe
    • CMGRDIAN.EXE
    • CMON016.EXE
    • CPD.EXE
    • CPF9X206.EXE
    • CPFNT206.EXE
    • CV.EXE
    • CWNB181.EXE
    • CWNTDWMO.EXE
    • D3dupdate.exe
    • DEFWATCH.EXE
    • DEPUTY.EXE
    • dfw.exe
    • DPF.EXE
    • DPFSETUP.EXE
    • DRWATSON.EXE
    • DRWEBUPW.exe
    • DRWEBUPW.EXE
    • Ecengine.exe
    • ENT.EXE
    • Esafe.exe
    • ESCANH95.EXE
    • ESCANHNT.EXE
    • ESCANV95.EXE
    • EXANTIVIRUS-CNET.EXE
    • FAST.EXE
    • Findviru.exe
    • FIREWALL.EXE
    • FLOWPROTECTOR.EXE
    • Fprot.exe
    • F-prot95.exe
    • Fp-win.exe
    • FP-WIN_TRIAL.EXE
    • FRW.EXE
    • FSAV.EXE
    • fsav32.exe
    • FSAV530STBYB.EXE
    • FSAV530WTBYB.EXE
    • FSAV95.EXE
    • fsbwsys.exe
    • fsgk32.exe
    • fsm32.exe
    • fssm32.exe
    • fvprotect.exe
    • GBMENU.EXE
    • GBPOLL.EXE
    • GUARD.EXE
    • Guarddog.exe
    • HACKTRACERSETUP.EXE
    • HTLOG.EXE
    • HWPE.EXE
    • Iamapp.exe
    • IAMAPP.EXE
    • IAMSERV.EXE
    • ICLOAD95.EXE
    • ICLOADNT.EXE
    • ICMON.EXE
    • ICSSUPPNT.exe
    • ICSSUPPNT.EXE
    • ICSUPP95.exe
    • ICSUPP95.EXE
    • ICSUPPNT.EXE
    • IFW2000.EXE
    • Iomon98.exe
    • IPARMOR.EXE
    • IRIS.EXE
    • JAMMER.EXE
    • KAVLITE40ENG.EXE
    • KAVPERS40ENG.EXE
    • KERIO-PF-213-EN-WIN.EXE
    • KERIO-WRL-421-EN-WIN.EXE
    • KERIO-WRP-421-EN-WIN.EXE
    • KILLPROCESSSETUP161.EXE
    • LDPRO.EXE
    • LOCALNET.EXE
    • LOCKDOWN.EXE
    • LOCKDOWN2000.EXE
    • Lookout.exe
    • LSETUP.EXE
    • LUALL.exe
    • LUCOMSERVER.EXE
    • LUINIT.EXE
    • mcagent.exe
    • MCAGENT.EXE
    • MCUPDATE.exe
    • MCUPDATE.EXE
    • MFW2EN.EXE
    • MFWENG3.02D30.EXE
    • MGUI.EXE
    • MINILOG.EXE
    • MOOLIVE.EXE
    • MRFLUX.EXE
    • msblast.exe
    • MSCONFIG.EXE
    • MSINFO32.EXE
    • MSSMMC32.EXE
    • MU0311AD.EXE
    • NAV80TRY.EXE
    • NAVAPSvc.exe
    • Navapsvc.exe
    • Navapw32.exe
    • navdx.exe
    • NAVDX.EXE
    • navstub.exe
    • NAVSTUB.EXE
    • Navt.exe
    • Navw32.exe
    • Navwnt.exe
    • Navwt.exe
    • nc2000.exe
    • NC2000.EXE
    • NCINST4.EXE
    • ndd32.exe
    • NDD32.EXE
    • NEOMONITOR.EXE
    • netarmor.exe
    • NETARMOR.EXE
    • netinfo.exe
    • NETINFO.EXE
    • netmon.exe
    • NETMON.EXE
    • NETSCANPRO.EXE
    • NETSPYHUNTER-1.2.EXE
    • NETSTAT.EXE
    • NISSERV.EXE
    • NISUM.EXE
    • nmain.exe
    • NMAIN.EXE
    • Nod32.exe
    • NORTON_INTERNET_SECU_3.0_407.EXE
    • NPF40_TW_98_NT_ME_2K.EXE
    • NPFMESSENGER.EXE
    • nprotect.exe
    • NSCHED32.EXE
    • Nsplugin.exe
    • ntvdm.exe
    • NTVDM.EXE
    • NUPGRADE.exe
    • NUPGRADE.exe
    • NVARCH16.EXE
    • NWINST4.EXE
    • NWTOOL16.EXE
    • Ogrc.exe
    • ostronet.exe
    • OSTRONET.EXE
    • Outpost.exe
    • OUTPOST.EXE
    • OUTPOSTINSTALL.EXE
    • OUTPOSTPROINSTALL.EXE
    • PADMIN.EXE
    • PANIXK.EXE
    • PAVPROXY.EXE
    • PCC2002S902.EXE
    • PCC2K_76_1436.EXE
    • pccguide.exe
    • pcciomon.exe
    • PCCIOMON.EXE
    • PCDSETUP.EXE
    • PCFWALLICON.EXE
    • PCIP10117_0.EXE
    • PDSETUP.EXE
    • PERISCOPE.EXE
    • PERSFW.EXE
    • PF2.EXE
    • PFWADMIN.EXE
    • PINGSCAN.EXE
    • PLATIN.EXE
    • POPROXY.EXE
    • POPSCAN.EXE
    • PORTDETECTIVE.EXE
    • PPINUPDT.EXE
    • PPTBC.EXE
    • PPVSTOP.EXE
    • PROCEXPLORERV1.0.EXE
    • PROPORT.EXE
    • PROTECTX.EXE
    • PSPF.EXE
    • PURGE.EXE
    • PVIEW95.EXE
    • QCONSOLE.EXE
    • QSERVER.EXE
    • Rav7.exe
    • RAV8WIN32ENG.EXE
    • regedit.exe
    • regedit32.exe
    • RESCUE.EXE
    • RESCUE32.EXE
    • RRGUARD.EXE
    • RSHELL.EXE
    • RTVSCN95.EXE
    • Rulaunch.exe
    • RULAUNCH.EXE
    • SAFEWEB.EXE
    • SAVScan.exe
    • SBSERV.EXE
    • Scan32.exe
    • SD.EXE
    • SETUP_FLOWPROTECTOR_US.EXE
    • SETUPVAMEEVAL.EXE
    • SFC.EXE
    • SGSSFW32.EXE
    • SHELLSPYINSTALL.EXE
    • SHN.EXE
    • SMC.EXE
    • Smss.exe
    • SOFI.EXE
    • SPF.EXE
    • SPHINX.EXE
    • Spider.exe
    • SPYXX.EXE
    • SS3EDIT.EXE
    • ST2.EXE
    • SUPFTRL.EXE
    • SUPPORTER5.EXE
    • SYMPROXYSVC.EXE
    • SYSEDIT.EXE
    • taskmgr.exe
    • TASKMON.EXE
    • TAUMON.EXE
    • TAUSCAN.EXE
    • TC.EXE
    • TCA.EXE
    • TCM.EXE
    • TDS2-98.EXE
    • TDS2-NT.EXE
    • TDS-3.EXE
    • TFAK5.EXE
    • TGBOB.EXE
    • TITANIN.EXE
    • TITANINXP.EXE
    • tnbutil.exe
    • TRACERT.EXE
    • TRJSCAN.EXE
    • TRJSETUP.EXE
    • TROJANTRAP3.EXE
    • UNDOBOOT.EXE
    • UPDATE.exe
    • UPDATE.EXE
    • VBCMSERV.EXE
    • vbcons.exe
    • VBCONS.EXE
    • vbsntw.exe
    • vbust.exe
    • VBUST.EXE
    • VBWIN9X.EXE
    • VBWINNTW.EXE
    • VCSETUP.EXE
    • Vet95.exe
    • Vettray.exe
    • VFSETUP.EXE
    • VIRUSMDPERSONALFIREWALL.EXE
    • VNLAN300.EXEVNPC3000.EXE
    • VPC42.EXE
    • VPFW30S.EXE
    • VPTRAY.EXE
    • VSCENU6.02D30.EXE
    • VSECOMR.EXE
    • VSHWIN32.EXE
    • VSISETUP.EXE
    • Vsmain.exe
    • vsmain.exe
    • VSMAIN.EXE
    • vsmon.exe
    • VSMON.EXE
    • vsstat.exe
    • VSSTAT.EXE
    • VSWIN9XE.EXE
    • VSWINNTSE.EXE
    • VSWINPERSE.EXE
    • W32DSM89.EXE
    • W9X.EXE
    • WATCHDOG.EXE
    • WEBSCANX.EXE
    • WGFE95.EXE
    • WHOSWATCHINGME.EXE
    • winlogon.exe
    • WINRECON.EXE
    • WNT.EXE
    • WRADMIN.EXE
    • WRCTRL.EXE
    • WSBGATE.EXE
    • WYVERNWORKSFIREWALL.EXE
    • XPF202EN.EXE
    • ZAPRO.EXE
    • ZAPSETUP3001.EXE
    • ZATUTOR.EXE
    • ZAUINST.EXE
    • Zonalarm.exe
    • ZONALM2601.EXE
    • ZONEALARM.EXE

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: Rodney Andres

Discovered: January 26, 2005
Updated: February 13, 2007 12:32:05 PM
Also Known As: Win32.Ahker.B [Computer Associ, Email-Worm.Win32.Anker.a [Kasp, W32/Ahker-B [Sophos]WORM_AHKER
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. Run a full system scan and delete all the files detected as W32.Ahker.B@mm.
  4. Delete the value that was added to the registry.
  5. Re-enable the SharedAccess service.
For specific details on each of these steps, read the following instructions.

1. To disable 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. To update 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 daily. 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.
Note: If you see an error, such as LU1418, when you try to run LiveUpdate and you cannot get the Web site hosting the Intelligent Updater, it is likely that W32.Ahker.B@mm has modified the Hosts file. You can either download and install LiveUpdate 2.5, which can remove Symantec entries from that file, or you can edit it yourself. See the instructions for both in the "Additional Information" section below.


3. To scan for and delete 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.Ahker.B@mm, click Delete.

    Note:
    If your Symantec antivirus product reports that it cannot delete an infected file, Windows may be using the file. To fix this, run the scan in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode." Once you have restarted in Safe mode, run the scan again.

    After the files are deleted, restart the computer in Normal mode and proceed with section 4.

4. To delete the value from the registry
Important: 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 subkeys only. Read the document, "How to make a backup of the Windows registry ," for instructions.
  1. Before you can use regedit.exe, you must download the file UnhookExec.exe. This can be downloaded from the Symantec security response website at http://www.symantec.com/avcenter/venc/data/tool.to.reset.shellopencommand.registry.keys.html.
  2. After downloading UnhookExec.exe, navigate to the folder it was downloaded to, right click on it and select Install.
  3. Open up the command prompt by clicking Click Start > Programs > Accessories > Command Prompt.
  4. Type regedit

  5. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

    and the right pane, delete the value:

    "Norton Auto-Protect" = "SERVICES.exe"

  6. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
    Policies\System

    and in the right pane, delete the values:

    "DisableTaskMgr" = "dword:00000001"
    "DisableRegistryTools" = "dword:00000001" (Note this value for this may have changed to 0 after installing UnhookExec.exe)

  7. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
    Policies\Explorer

    and in the right pane, delete the value:

    "NoRun" = "dword:00000001"

  8. Navigate to and delete the subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
    Policies\Explorer\DisallowRun

  9. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\
    systemrestore

    and in the right pane, delete the value:

    "DisableSR" = "dword:00000001"

  10. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\
    WindowsUpdate\AU

    and in the right pane, delete the value:

    "NoAutoUpdate" = "dword:00000001"

  11. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\
    WindowsUpdate\auto update

    and in the right pane, delete the value:

    "[default]" = "SERVICES.exe"

  12. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\security center

    and in the right pane, delete the values:

    "UpdatesDisableNotify" = "dword:00000001"
    "FirewallDisableNotify" = "dword:00000001"
    "AntiVirusDisableNotify" = "dword:00000001"

  13. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\
    systemrestore

    and in the right pane, delete the value:

    "DisableSR" = "dword:00000001"

  14. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\
    WindowsUpdate\AU

    and in the right pane, delete the value:

    "NoAutoUpdate" = "dword:00000001"

  15. Navigate to the subkey:

    HKEY_CURRENT_USER\Software\Microsoft\security center

    and in the right pane, delete the values:

    "UpdatesDisableNotify" = "dword:00000001"
    "FirewallDisableNotify" = "dword:00000001"
    "AntiVirusDisableNotify" = "dword:00000001"

  16. Navigate to the subkey:

    HKEY_CLASSES_ROOT\txtfile\shell\open\command

    and delete the value:

    "[default]" = "SERVICES.EXE %1"

  17. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\txtfile\shell\open\command

    and delete the value:

    "[default]" = "SERVICES.EXE %1"

  18. Navigate to and delete the subkey:

    HKEY_CLASSES_ROOT\RDP.File

  19. Navigate to and delete the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\RDP.File

  20. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\app paths\LUALL.exe

    and delete the value:

    "[default]" = "SERVICES.exe"

  21. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    Runservices-

    and delete the value:

    "Windows Service" = "SERVICES.exe"

  22. Navigate to and delete the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Agent Hacker

  23. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ComputerName\
    ActiveComputerName

    And restore the value:

    "ComputerName" = "Agent Hacker"

  24. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion

    and restore the value:

    "ProductId" = "Agent Hacker"

  25. Navigate to and delete the subkey:

    HKEY_LOCAL_MACHINE\System\wpa\Key-MGM9K8XQ2GHRBGTP2TR93

  26. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Registration

    and restore the value:

    "ProductID" = "Agent Hacker"

  27. Exit the Registry Editor.

5. To re-enable the SharedAccess service (Windows 2000/XP only)
The SharedAccess service is responsible for maintaining Internet Connection Sharing and the Windows Firewall/Internet Connection Firewall applications in Windows. (The presence and names of these applications vary depending on the operating system and service pack you are using.) To protect your computer and maintain network functionality, re-enable this service if you are using any of these programs.


Windows XP Service Pack 2
If you are running Windows XP with Service Pack 2 and are using the Windows Firewall, the operating system will alert you when the SharedAccess service is stopped, by displaying an alert balloon saying that your Firewall status is unknown. Perform the following steps to ensure that the Windows Firewall is re-enabled:
  1. Click Start > Control Panel.

  2. Double-click the Security Center.

  3. Ensure that the Firewall security essential is marked ON.

    Note: If the Firewall security essential is marked on, your Windows Firewall is on and you do not need to continue with these steps.

    If the Firewall security essential is not marked on, click the "Recommendations" button.

  4. Under "Recommendations," click Enable Now. A window appears telling you that the Windows Firewall was successfully turned on.

  5. Click Close, and then click OK.

  6. Close the Security Center.


Windows 2000 or Windows XP Service Pack 1 or earlier
Complete the following steps to re-enable the SharedAccess service:
  1. Click Start > Run.
  2. Type services.msc

    Then click OK.

  3. Do one of the following:
    • Windows 2000: Under the Name column, locate the "Internet Connection Sharing (ICS)" service and double-click it.
    • Windows XP: Under the Named column, locate the "Internet Connection Firewall (ICF) / Internet Connection Sharing (ICS)" service and double-click it.

  4. Under "Startup Type:", select "Automatic" from the drop-down menu.

  5. Under "Service Status:", click the Start button.

  6. Once the service has completed starting, click OK.

  7. Close the Services window.


Writeup By: Rodney Andres