W32.Derdero.B@mm

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Discovered: February 19, 2005
Updated: February 13, 2007 12:33:42 PM
Also Known As: W32/Derdero.b@MM [McAfee], WORM_DERDERO.A [Trend Micro]
Type: Worm
Systems Affected: Windows


W32.Derdero.B@mm is a mass-mailing worm that uses its own SMTP engine to send an email to addresses that it gathers from the Windows Address Book. It also attempts to spread through file-sharing programs and infects all .exe files on the C drive.



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 12 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 12 of the "Technical Details" section.
    14. Close Notepad and save your changes when prompted.


Antivirus Protection Dates

  • Initial Rapid Release version February 19, 2005
  • Latest Rapid Release version December 01, 2017 revision 032
  • Initial Daily Certified version February 19, 2005
  • Latest Daily Certified version December 02, 2017 revision 001
  • Initial Weekly Certified release date February 20, 2005

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

Writeup By: Dong Hoon Lee

Discovered: February 19, 2005
Updated: February 13, 2007 12:33:42 PM
Also Known As: W32/Derdero.b@MM [McAfee], WORM_DERDERO.A [Trend Micro]
Type: Worm
Systems Affected: Windows


When W32.Derdero.A@mm is executed, it performs the following actions:

  1. Displays the following message:

    Title:
    Fatal Error

    Text:
    Can',27h,'t access byte pointer

  2. Creates the following files:

    • %System%\systemDA.exe
    • %System%\nCalc.exe
    • %System%\lzsys.sys
    • %System%\lesys.sys
    • %System%\ReadMe.2.txt

      Notes: %System% is a variable that refers to the System folder. By default this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).

  3. Overwrites the file %System%\hal.dll in an attempt to prevent the user from restarting the compromised computer correctly.

    Note: %SYSTEM%\hal.dll is part of the Windows hardware abstraction layer. Infecting it may cause Windows to fail to reboot properly.

  4. Creates the following files in the same folder as the originally executed file:

    • [blank spaces].exe
    • [blank spaces].pif

  5. Attempts to create the following files in folders containing the string "shar":

    • Adobe Photoshop 6 Full Version.exe
    • Adobe Photoshop 6 Full Version.exe
    • Windows Longhorn BETA.iso[blank spaces].exe
    • WinAmp 5 Crack.exe
    • WinRAR.exe
    • Windows XP Pro SP2.pif
    • Young teen gets reamed.mpg[blank spaces].pif
    • jenna jameson screensaver.scr
    • Internet Explorer 7.exe
    • Snood new version.exe
    • Tits.mpeg[blank spaces].scr
    • Norton AntiVirus 2006 BETA.exe
    • Battlefield 1942.exe
    • NETSKY SOURCE CODE.zip[blank spaces].exe
    • Kazaa Lite 2005 Edition.zip[blank spaces].pif
    • Windows XP crack.zip[blank spaces].exe
    • Hot Teen Porn.mpeg[blank spaces].exe
    • Britney spears naked Playboy.jpeg[blank spaces].pif
    • DVD Copier.exe
    • Visual Studio.NET.FULL.rar[blank spaces].exe

  6. Adds the value:

    "System Database administration" = "%System%\systemDA.exe"

    to the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

    so that it is executed every time Windows starts.

  7. Creates the following mutexes:

    • AdmMoodownJKIS003
    • (S)(k)(y)(N)(e)(t)
    • ____--->>>>U<<<<--____
    • NetDy_Mutex_Psycho
    • _-=oOOSOkOyONOeOtOo=-_
    • SyncMutex_USUkUyUnUeUtUU
    • SyncMutex_USUkUyUnUeUtU
    • Protect_USUkUyUnUeUtU_Mutex
    • 89845848594808308439858307378280987074387498739847
    • _-oOaxX|-+S+-+k+-+y+-+N+-+e+-+t+-|XxKOo-_
    • _-oO]xX|-S-k-y-N-e-t-|Xx[Oo-_
    • Bgl_*L*o*o*s*e*
    • Rabbo_Mutex
    • Rabbo
    • SkYnEt_AVP
    • KO[SkyNet.cz]SystemsMutex
    • MI[SkyNet.cz]SystemsMutex
    • Netsky AV Guard
    • LK[SkyNet.cz]SystemsMutex
    • [SkyNet.cz]SystemsMutex
    • AdmSkynetJKIS003
    • SkyNet-Sasser
    • S-k-y-n-e-t--A-n-t-i-v-i-r-u-s-T-e-a-m
    • MuXxXxTENYKSDesignedAsTheFollowerOfSkynet-D
    • Jobaka3
    • Jobaka3l
    • JumpallsNlsTillt
    • SkynetSasserVersionWithPingFast
    • SkynetNotice
    • ~~~Bloodred~~~owns~~~you~~~xoxo~~~2004
    • 'D'r'o'p'p'e'd'S'k'y'N'e't'
    • DrDetroit[Bloodred.B]

  8. Gathers email addresses from the Windows Address Book. The worm will ignore email addresses that contain any of the following strings:

    • @symantec
    • @panda
    • @avp
    • @microsoft
    • @msn
    • @sopho
    • @mm
    • @norman
    • @norton
    • @noreply
    • @virusli
    • @fsecure
    • @hotmail
    • @gmai
    • @vir

  9. Uses its own SMTP engine to send a copy of itself to the email addresses that it finds. The email has the following characteristics:

    From:
    The From address is spoofed and may be one of following:

    • server
    • administration
    • management
    • service
    • userhelp
    • virus
    • support

      Subject:
      One of the following:

    • Information
    • Virus alert
    • Spyware Alert!
    • Hackers on the loose

      Message Body:
      One of the following:

    • Hackers are on the loose after recent discovery of the KaB exploit. To
      help protect your computer, read the attached file.
    • A new kind of virus unlike you've ever seen is quickly spreading. Read
      the attachment for more
    • The attached file contains information on how to remove most kinds of
      spyware
    • Attached is a document with details pertaining on how to remove the
      latest viruses circulating

      Attachment:
      One of the following:

    • patch
    • info
    • help
    • SpyFix
    • FixVir

      with one of the following extensions:

    • .scr
    • .pif
    • .cmd
    • .exe
    • .doc.pif
    • .txt.exe
    • .doc.cmd
    • .doc.exe
    • .txt.pif

  10. Checks the network connection by accessing www.kazaa.com.

  11. Closes the Windows Task Manager, if it is opened.

  12. Blocks access to several Web sites by appending the following text to the hosts file:

    127.0.0.1 www.norton.com
    127.0.0.1 norton.com
    127.0.0.1 yahoo.com
    127.0.0.1 www.yahoo.com
    127.0.0.1 microsoft.com
    127.0.0.1 www.microsoft.com
    127.0.0.1 windowsupdate.com
    127.0.0.1 www.windowsupdate.com
    127.0.0.1 www.mcafee.com
    127.0.0.1 mcafee.com
    127.0.0.1 www.nai.com
    127.0.0.1 nai.com
    127.0.0.1 www.ca.com
    127.0.0.1 ca.com
    127.0.0.1 liveupdate.symantec.com
    127.0.0.1 www.sophos.com
    127.0.0.1 www.google.com
    127.0.0.1 google.com
    127.0.0.1 rohitab.com
    127.0.0.1 www.rohitab.com
    127.0.0.1 securityresponse.symantec.com
    127.0.0.1 google.ca
    127.0.0.1 www.google.ca

  13. Infects all .exe files on the C drive.

  14. Attempts to end the following processes:

    • AGENTSVR.EXE
    • ANTI-TROJAN.EXE
    • ANTIVIRUS.EXE
    • ANTS.EXE
    • APIMONITOR.EXE
    • APLICA32.EXE
    • APVXDWIN.EXE
    • ATCON.EXE
    • ATGUARD.EXE
    • ATRO55EN.EXE
    • ATUPDATER.EXE
    • ATWATCH.EXE
    • AUPDATE.EXE
    • AUTODOWN.EXE
    • AUTOTRACE.EXE
    • AUTOUPDATE.EXE
    • AVCONSOL.EXE
    • AVGSERV9.EXE
    • AVLTMAIN.EXE
    • AVPUPD.EXE
    • AVSYNMGR.EXE
    • AVWUPD32.EXE
    • AVXQUAR.EXE
    • AVprotect9x.exe
    • Au.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
    • CLEAN.EXE
    • CLEANER.EXE
    • CLEANER3.EXE
    • CLEANPC.EXE
    • CMGRDIAN.EXE
    • CMON016.EXE
    • CPD.EXE
    • CPF9X206.EXE
    • CPFNT206.EXE
    • CV.EXE
    • CWNB181.EXE
    • CWNTDWMO.EXE
    • D3dupdate.exe
    • DEFWATCH.EXE
    • DEPUTY.EXE
    • DPF.EXE
    • DPFSETUP.EXE
    • DRWATSON.EXE
    • DRWEBUPW.EXE
    • ENT.EXE
    • ESCANH95.EXE
    • ESCANHNT.EXE
    • ESCANV95.EXE
    • EXANTIVIRUS-CNET.EXE
    • FAST.EXE
    • FIREWALL.EXE
    • FLOWPROTECTOR.EXE
    • FP-WIN_TRIAL.EXE
    • FRW.EXE
    • FSAV.EXE
    • FSAV530STBYB.EXE
    • FSAV530WTBYB.EXE
    • FSAV95.EXE
    • GBMENU.EXE
    • GBPOLL.EXE
    • GUARD.EXE
    • HACKTRACERSETUP.EXE
    • HTLOG.EXE
    • HWPE.EXE
    • IAMAPP.EXE
    • IAMSERV.EXE
    • ICLOAD95.EXE
    • ICLOADNT.EXE
    • ICMON.EXE
    • ICSSUPPNT.EXE
    • ICSUPP95.EXE
    • ICSUPPNT.EXE
    • IFW2000.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
    • LSETUP.EXE
    • LUALL.EXE
    • LUCOMSERVER.EXE
    • LUINIT.EXE
    • MCAGENT.EXE
    • MCUPDATE.EXE
    • MFW2EN.EXE
    • MFWENG3.02D30.EXE
    • MGUI.EXE
    • MINILOG.EXE
    • MOOLIVE.EXE
    • MRFLUX.EXE
    • MSCONFIG.EXE
    • MSINFO32.EXE
    • MSSMMC32.EXE
    • MU0311AD.EXE
    • NAV80TRY.EXE
    • NAVAPW32.EXE
    • NAVDX.EXE
    • NAVSTUB.EXE
    • NAVW32.EXE
    • NC2000.EXE
    • NCINST4.EXE
    • NDD32.EXE
    • NEOMONITOR.EXE
    • NETARMOR.EXE
    • NETINFO.EXE
    • NETMON.EXE
    • NETSCANPRO.EXE
    • NETSPYHUNTER-1.2.EXE
    • NETSTAT.EXE
    • NISSERV.EXE
    • NISUM.EXE
    • NMAIN.EXE
    • NORTON_INTERNET_SECU_3.0_407.EXE
    • NPF40_TW_98_NT_ME_2K.EXE
    • NPFMESSENGER.EXE
    • NPROTECT.EXE
    • NSCHED32.EXE
    • NTVDM.EXE
    • NUPGRADE.EXE
    • NVARCH16.EXE
    • NWINST4.EXE
    • NWTOOL16.EXE
    • OSTRONET.EXE
    • OUTPOST.EXE
    • OUTPOSTINSTALL.EXE
    • OUTPOSTPROINSTALL.EXE
    • PADMIN.EXE
    • PANIXK.EXE
    • PAVPROXY.EXE
    • PCC2002S902.EXE
    • PCC2K_76_1436.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
    • RAV8WIN32ENG.EXE
    • RESCUE.EXE
    • RESCUE32.EXE
    • RRGUARD.EXE
    • RSHELL.EXE
    • RTVSCN95.EXE
    • RULAUNCH.EXE
    • SAFEWEB.EXE
    • SBSERV.EXE
    • SD.EXE
    • SETUPVAMEEVAL.EXE
    • SETUP_FLOWPROTECTOR_US.EXE
    • SFC.EXE
    • SGSSFW32.EXE
    • avserve2.exe
    • SHELLSPYINSTALL.EXE
    • SHN.EXE
    • SMC.EXE
    • SOFI.EXE
    • SPF.EXE
    • SPHINX.EXE
    • SPYXX.EXE
    • SS3EDIT.EXE
    • ST2.EXE
    • SUPFTRL.EXE
    • SUPPORTER5.EXE
    • SYMPROXYSVC.EXE
    • SYSEDIT.EXE
    • TASKMON.EXE
    • TAUMON.EXE
    • TAUSCAN.EXE
    • TC.EXE
    • TCA.EXE
    • TCM.EXE
    • TDS-3.EXE
    • TDS2-98.EXE
    • TDS2-NT.EXE
    • TFAK5.EXE
    • TGBOB.EXE
    • TITANIN.EXE
    • TITANINXP.EXE
    • TRACERT.EXE
    • TRJSCAN.EXE
    • TRJSETUP.EXE
    • TROJANTRAP3.EXE
    • UNDOBOOT.EXE
    • UPDATE.EXE
    • VBCMSERV.EXE
    • VBCONS.EXE
    • VBUST.EXE
    • VBWIN9X.EXE
    • VBWINNTW.EXE
    • VCSETUP.EXE
    • VFSETUP.EXE
    • VIRUSMDPERSONALFIREWALL.EXE
    • VNLAN300.EXE
    • VNPC3000.EXE
    • VPC42.EXE
    • VPFW30S.EXE
    • VPTRAY.EXE
    • VSCENU6.02D30.EXE
    • VSECOMR.EXE
    • VSHWIN32.EXE
    • VSISETUP.EXE
    • VSMAIN.EXE
    • VSMON.EXE
    • VSSTAT.EXE
    • VSWIN9XE.EXE
    • VSWINNTSE.EXE
    • VSWINPERSE.EXE
    • W32DSM89.EXE
    • W9X.EXE
    • WATCHDOG.EXE
    • WEBSCANX.EXE
    • WGFE95.EXE
    • WHOSWATCHINGME.EXE
    • WINRECON.EXE
    • WNT.EXE
    • WRADMIN.EXE
    • WRCTRL.EXE
    • WSBGATE.EXE
    • WYVERNWORKSFIREWALL.EXE
    • XPF202EN.EXE
    • ZAPRO.EXE
    • ZAPSETUP3001.EXE
    • ZATUTOR.EXE
    • ZAUINST.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: Dong Hoon Lee

Discovered: February 19, 2005
Updated: February 13, 2007 12:33:42 PM
Also Known As: W32/Derdero.b@MM [McAfee], WORM_DERDERO.A [Trend Micro]
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. Restore Hal.Dll
  2. Disable System Restore (Windows Me/XP).
  3. Update the virus definitions.
  4. Run a full system scan and delete all the files detected as W32.Derdero.B@mm.
  5. Delete the value that was added to the registry.
For specific details on each of these steps, read the following instructions.

1. To restore hal.dll
Important : This must be done before you restart your computer, otherwise windows may not restart properly.
  1. Click Start > Programs > Accessories > Command Prompt
  2. Type sfc /scannow
  3. Insert the windows install CD when prompted.


2. 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.


3. 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 the worm 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.


4. 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.Derdero.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 5.

5. 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. Click Start > Run.
  2. Type regedit

    Then click OK.

  3. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  4. In the right pane, delete the value:

    "System Database administration" = "%System%\systemDA.exe"

  5. Exit the Registry Editor.


Writeup By: Dong Hoon Lee