W32.Yaha.AE@mm

Printer Friendly Page

Discovered: October 22, 2003
Updated: February 13, 2007 12:12:44 PM
Type: Worm
Systems Affected: Windows


W32.Yaha.AE@mm is a variant of the W32.Yaha.J@mm worm that does the following:

  • Terminates some antivirus and firewall processes.
  • Uses its own SMTP engine to email itself to all the contacts in Windows Address Book, MSN Messenger, .NET Messenger, Yahoo Pager, ICQ Pager, as well as in all the files whose extensions contain the letters HT.
  • Attempts to spread itself through network-shared folders and mapped drives.
  • Attempts to spread itself through the KaZaA file-sharing network.
  • Installs a keylogger and emails the logs to its author.
  • Performs Denial of Service (DoS) attacks to some specified and random hosts on TCP ports 135, 139, and 445.

The email message has a randomly chosen subject line, message, and attachment name. The attachment will have a .com, .exe, or .zip file extension.

This threat is written in the Microsoft Visual C++ programming language and is compressed with FSG.

Antivirus Protection Dates

  • Initial Rapid Release version October 23, 2003
  • Latest Rapid Release version October 23, 2003
  • Initial Daily Certified version October 23, 2003
  • Latest Daily Certified version October 23, 2003
  • Initial Weekly Certified release date October 24, 2003

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

Writeup By: Yana Liu

Discovered: October 22, 2003
Updated: February 13, 2007 12:12:44 PM
Type: Worm
Systems Affected: Windows


When W32.Yaha.AE runs, it does the following:

  1. Copies itself as these files:

    %System%\mexplore.exe
    %System%\cmde32.exe
    %CommonStartup%\mexplore.exe
    %CurrentUserStartup%\mexplore.exe

    The attributes of the files are set to Hidden.

    Notes:
      • %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).
      • %CommonStartup% is a variable. The worm retrieves the common Windows Startup folder from the registry key:

        HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders

        For example, for Windows 98 system, it can be C:\Windows\All Users\Start Menu\Programs\Startup
      • %CurrentUserStartup% is a variable. The worm retrieves the current user's Windows Startup folder from the registry key:

        HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders

        For example, for Windows 98 system, it can be C:\Windows\Start Menu\Programs\Startup

  2. Creates the files:

    %Windir%\Hosts
    %Windir%\Lmhosts
    %System\etc\hosts
    %System\etc\Lmhosts

    Microsoft TCP/IP for Windows uses Hosts and Lmhosts. Hosts contains the mappings of IP addresses to host names. Lmhosts contains the mappings of IP addresses to computernames # (NetBIOS) names. The worm creates these two files with the following text:

    127.0.0.1 www.symantec.com
    127.0.0.1 www.microsoft.com
    127.0.0.1 www.sophos.com
    127.0.0.1 www.avp.ch
    127.0.0.1 www.mcafee.com
    127.0.0.1 www.trendmicro.com
    127.0.0.1 www.pandasoftware.com
    127.0.0.1 www3.ca.com
    127.0.0.1 www.ca.com

    As a result, the infected computer cannot get to these Web sites.

    Note: These files are not viral by themselves, and therefore Symantec antivirus products do not detect them. Restore the files from a clean backup if the worm overwrote them, or simply delete them.

  3. Creates the file %System%\SCHED32.dll. The worm retrieves email addresses and stores them in this file.

    Note: This file is not viral by itself, and therefore Symantec antivirus products do not detect them. Deleted the file if found.

  4. Creates the file %Cookies%\%Cookies%\anyuser@yahoo.com.txt, which is a Keylogger.Trojan.

    Note: %Cookies% is a variable. The worm locates the Cookies folder and inserts a Keylogger.Trojan anyuser@yahoo.com.txt in that location.

  5. Adds the value:

    "MS Explorer"="%System%\mexplore.exe"

    to the registry keys:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices

    so that the worm runs when you start Windows.

  6. Modifies the default values in the registry keys:

    HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\batfile\shell\open\command
    HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\comfile\shell\open\command
    HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\exefile\shell\open\command
    HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\piffile\shell\open\command
    HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\scrfile\shell\open\command

    to:

    @=""%System%\cmde32.exe""%1"%*"

  7. Disables the registry tools by setting the value:

    "DisableRegistryTools"=1

    in the registry key:

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

  8. Creates the keys:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RedWorm
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Winver
    HKEY_LOCAL_MACHINE\Winver

  9. Deletes the values:

    syshelp
    WinGate initialize
    Module Call initialize
    WinServices
    WindowsMGM

    from the registry key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  10. Deletes the value "WinServices" from the registry key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices

  11. Deletes the value "WindowsMGM" from the registry key:

    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices

  12. Registers itself as a service process.

  13. Terminates the following processes, if they are active:
    • Winservices
    • TCPSVS32
    • NAV32_LOADER
    • WINGATE.EXE
    • SYSHELP.EXE
    • WINMGM32.EXE
    • WINK

  14. Deletes the following files, if any of them exist:
    • %System%\WinServices.exe
    • %System%\nav32_loader.exe
    • %System%\tcpsvs32.exe
    • %System%\syshelp.exe
    • %System%\WinGate.exe
    • %System%\WinRpcsrv.exe
    • %System%\winmgm32.exe
    • %Windir%\SNTMLS.DAT

  15. Enumerates the active windows, and if the name of the window contains any of the following strings, the worm will attempt to terminate that process:
    • Windows Task Manager
    • System Configuration Utility
    • Registry Editor
    • Process Viewer

  16. Enumerates the active processes, and if the name of the process contains any of the following strings, it will attempt to terminate a process:
    • _AVP32
    • _AVP32.EXE
    • _AVPCC
    • _AVPCC
    • _AVPCC.EXE
    • _AVPM
    • _AVPM.EXE
    • AckWin32
    • AckWin32
    • ACKWIN32
    • AckWin32.exe
    • AckWin32.exe
    • ACKWIN32.EXE
    • ADVXDWIN
    • ADVXDWIN.EXE
    • agentw.exe
    • ALERTSVC
    • ALERTSVC.EXE
    • ALOGSERV
    • alogserv
    • ALOGSERV
    • alogserv.exe
    • ALOGSERV.EXE
    • AMON9X
    • AMON9X.EXE
    • ANTI-TROJAN
    • ANTI-TROJAN.EXE
    • ANTS
    • ANTS.EXE
    • APVXDWIN
    • apvxdwin
    • APVXDWIN.EXE
    • apvxdwin.exe
    • ATCON
    • ATCON.EXE
    • ATUPDATER
    • ATUPDATER.EXE
    • ATWATCH
    • ATWATCH.EXE
    • AUTODOWN
    • AutoDown
    • AUTODOWN
    • AUTODOWN.exe
    • AutoDown.exe
    • AUTODOWN.EXE
    • AutoTrace
    • AutoTrace.exe
    • AVCONSOL
    • AVCONSOL.EXE
    • AVGCC32
    • AVGCC32
    • AVGCC32.EXE
    • AVGCC32.EXE
    • AVGCTRL
    • Avgctrl
    • AVGCTRL.EXE
    • Avgctrl.exe
    • AvgServ
    • AVGSERV
    • AvgServ
    • AVGSERV
    • AVGSERV.EXE
    • AVGSERV.EXE
    • AVGSERV9
    • AVGSERV9.EXE
    • AVGW
    • AVGW.EXE
    • avkpop
    • avkpop.exe
    • AvkServ
    • AvkServ.exe
    • avkservice
    • avkservice.exe
    • avkwctl9
    • avkwctl9.exe
    • AVP
    • AVP.EXE
    • AVP32
    • AVP32.EXE
    • AVPCC
    • avpm
    • avpm
    • AVPM
    • avpm.exe
    • AVPM.EXE
    • Avsched32
    • Avsched32.exe
    • AvSynMgr
    • AVSYNMGR
    • AVSYNMGR
    • AvSynMgr
    • AVSYNMGR
    • AVSYNMGR.exe
    • AVWINNT
    • AVWINNT.EXE
    • AVXMONITOR9X
    • AVXMONITOR9X
    • AVXMONITOR9X.EXE
    • AVXMONITOR9X.EXE
    • AVXMONITORNT
    • AVXMONITORNT
    • AVXMONITORNT.EXE
    • AVXMONITORNT.EXE
    • AVXQUAR
    • AVXQUAR
    • AVXQUAR.EXE
    • AVXQUAR.EXE.EXE
    • AVXW
    • AVXW.EXE
    • blackd
    • BLACKD
    • blackd.exe
    • BLACKD.EXE
    • BlackICE
    • BlackICE.exe
    • CDP.EXE
    • cfgWiz
    • cfgWiz.exe
    • Claw95
    • Claw95
    • CLAW95
    • Claw95.exe
    • Claw95.exe
    • CLAW95.EXE
    • Claw95cf
    • CLAW95CF
    • Claw95cf.exe
    • CLAW95CF.EXE
    • cleaner
    • cleaner.EXE
    • cleaner3
    • cleaner3.EXE
    • CMGRDIAN
    • CMGrdian
    • CMGRDIAN
    • CMGRDIAN.EXE
    • CONNECTIONMONITOR
    • CONNECTIONMONITOR.EXE
    • CPD
    • cpd.exe
    • cpd.exe
    • CPDClnt
    • CPDCLNT.EXE
    • CPDClnt.exe
    • CTRL
    • CTRL.EXE
    • defalert
    • defalert.exe
    • defscangui
    • defscangui.exe
    • DEFWATCH
    • DEFWATCH.EXE
    • DOORS
    • DOORS
    • DOORS.EXE
    • DOORS.EXE
    • DVP95
    • DVP95.EXE
    • DVP95_0
    • DVP95_0.EXE
    • EFPEADM
    • EFPEADM
    • EFPEADM.exe
    • EFPEADM.EXE
    • ETRUSTCIPE
    • ETRUSTCIPE
    • ETRUSTCIPE.exe
    • ETRUSTCIPE.EXE
    • EVPN
    • EVPN
    • EVPN.exe
    • EVPN.EXE
    • EXPERT
    • EXPERT.EXE
    • F-AGNT95
    • F-AGNT95.EXE
    • fameh32
    • fameh32.exe
    • fch32
    • fch32.exe
    • fih32
    • fih32.exe
    • fnrb32
    • fnrb32.exe
    • F-PROT
    • F-PROT.EXE
    • F-PROT95
    • F-PROT95.EXE
    • FP-WIN
    • FP-WIN.EXE
    • FRW
    • FRW
    • FRW.EXE
    • FRW.EXE
    • fsaa
    • fsaa.exe
    • fsav32
    • fsav32.exe
    • fsgk32
    • fsgk32.exe
    • fsm32
    • fsm32.exe
    • fsma32
    • fsma32.exe
    • fsmb32
    • fsmb32.exe
    • f-stopw
    • F-STOPW
    • f-stopw.exe
    • F-STOPW.EXE
    • gbmenu
    • gbmenu.exe
    • GBPOLL
    • gbpoll
    • GBPOLL.EXE
    • gbpoll.exe
    • GENERICS
    • GENERICS.EXE
    • GUARD
    • GUARD
    • GUARD.EXE
    • GUARD.EXE
    • GUARDDOG
    • GUARDDOG.EXE
    • iamapp
    • IAMAPP
    • IAMAPP
    • iamapp.exe
    • IAMAPP.EXE
    • IAMAPP.EXE
    • iamserv
    • IAMSERV
    • iamserv.exe
    • IAMSERV.EXE
    • IAMSTATS
    • IAMSTATS.EXE
    • ICLOAD95
    • ICLOAD95.EXE
    • ICLOADNT
    • ICLOADNT
    • ICLOADNT.EXE
    • ICLOADNT.EXE
    • ICMON
    • ICMON.EXE
    • ICSUPP95
    • ICSUPP95
    • ICSUPP95.EXE
    • ICSUPP95.EXE
    • ICSUPPNT
    • ICSUPPNT.EXE
    • IFACE
    • IFACE.EXE
    • IOMON98
    • IOMON98
    • IOMON98.EXE
    • IOMON98.EXE
    • ISRV95
    • ISRV95.EXE
    • JEDI
    • JEDI.EXE
    • LDNETMON
    • LDNETMON.EXE
    • LDPROMENU
    • LDPROMENU.EXE
    • LDSCAN
    • LDSCAN.EXE
    • LOCKDOWN
    • LOCKDOWN.EXE
    • lockdown2000
    • LOCKDOWN2000
    • lockdown2000.exe
    • LOCKDOWN2000.EXE
    • LUALL
    • LUALL.EXE
    • LUCOMSERVER
    • LUCOMSERVER.EXE
    • LUSPT
    • LUSPT.exe
    • MCAGENT
    • MCAGENT.EXE
    • MCMNHDLR
    • MCMNHDLR.EXE
    • Mcshield.exe
    • MCTOOL
    • MCTOOL.EXE
    • MCUPDATE
    • MCUPDATE.EXE
    • MCVSRTE
    • MCVSRTE.EXE
    • MCVSSHLD
    • MCVSSHLD.EXE
    • MGAVRTCL
    • MGAVRTCL.EXE
    • MGAVRTE
    • MGAVRTE.EXE
    • MGHTML
    • MGHTML.EXE
    • MINILOG
    • MINILOG.EXE
    • Monitor
    • MONITOR
    • Monitor.exe
    • MONITOR.EXE
    • MOOLIVE
    • MOOLIVE.EXE
    • MPFAGENT.EXE
    • MPFSERVICE
    • MPFSERVICE.exe
    • MPFTRAY.EXE
    • MWATCH
    • MWATCH
    • MWATCH.exe
    • MWATCH.EXE
    • NAV Auto-Protect
    • NAV Auto-Protect
    • NAVAP
    • NAVAP
    • navapsvc
    • navapsvc
    • NAVAPSVC.EXE
    • navapsvc.exe
    • navapw32
    • NAVAPW32
    • NAVAPW32.EXE
    • NAVENGNAVEX15
    • NAVENGNAVEX15
    • NAVLU32
    • NAVLU32.EXE
    • Navw32
    • NAVW32
    • Navw32.exe
    • NAVWNT
    • NAVWNT.EXE
    • NDD32
    • NDD32.EXE
    • NeoWatchLog
    • NeoWatchLog.exe
    • NETUTILS
    • NETUTILS.EXE
    • NISSERV
    • NISSERV
    • NISSERV.EXE
    • NISSERV.EXE
    • NISSERV.EXE
    • NISUM
    • NISUM
    • NISUM.EXE
    • NISUM.EXE
    • NMAIN
    • NMAIN.EXE
    • NORMIST
    • NORMIST
    • NORMIST.EXE
    • NORMIST.EXE
    • notstart
    • notstart.exe
    • NPROTECT
    • NPROTECT.EXE
    • npscheck
    • npscheck.exe
    • NPSSVC
    • NPSSVC.EXE
    • NSCHED32
    • NSCHED32.EXE
    • ntrtscan
    • ntrtscan.EXE
    • NTVDM
    • NTVDM.EXE
    • NTXconfig
    • NTXconfig.exe
    • Nui.EXE
    • Nupgrade
    • Nupgrade.exe
    • NVC95
    • NVC95
    • NVC95.EXE
    • NVC95.EXE
    • NVSVC32
    • NVSVC32
    • NWService
    • NWService.exe
    • NWTOOL16
    • NWTOOL16.EXE
    • PADMIN
    • PADMIN.EXE
    • PAVPROXY
    • pavproxy
    • PAVPROXY.EXE
    • pavproxy.exe
    • PCCIOMON
    • PCCIOMON
    • PCCIOMON.EXE
    • PCCIOMON.EXE
    • pccntmon
    • pccntmon.EXE
    • pccwin97
    • pccwin97.EXE
    • PCCWIN98
    • PCCWIN98.EXE
    • pcscan
    • pcscan.EXE
    • PERSFW
    • PERSFW.EXE
    • PERSWF
    • PERSWF.EXE
    • POP3TRAP
    • POP3TRAP.EXE
    • POPROXY
    • POPROXY.EXE
    • PORTMONITOR
    • PORTMONITOR.EXE
    • PROCESSMONITOR
    • PROCESSMONITOR.EXE
    • PROGRAMAUDITOR
    • PROGRAMAUDITOR.EXE
    • PVIEW95
    • PVIEW95.EXE
    • rapapp.exe
    • RAV7
    • RAV7.EXE
    • RAV7WIN
    • RAV7WIN.EXE
    • REALMON
    • REALMON.EXE
    • Rescue
    • RESCUE
    • Rescue.exe
    • RESCUE.EXE
    • RTVSCN95
    • RTVSCN95.EXE
    • RULAUNCH
    • RULAUNCH.EXE
    • sbserv
    • sbserv.exe
    • SCAN32
    • SCAN32.EXE
    • SCRSCAN
    • SCRSCAN.EXE
    • Smc
    • SMC.EXE
    • Sphinx
    • SPHINX
    • Sphinx.exe
    • SPHINX.EXE
    • SPYXX
    • SPYXX.EXE
    • SS3EDIT
    • SS3EDIT.EXE
    • SWEEP95
    • SWEEP95.EXE
    • SweepNet
    • SweepNet
    • SWEEPSRV.SYS
    • SWEEPSRV.SYS
    • SWNETSUP
    • SWNETSUP.EXE
    • SymProxySvc
    • SymProxySvc.exe
    • SYMTRAY
    • SYMTRAY.EXE
    • TAUMON
    • TAUMON.EXE
    • TC.EXE
    • TCA
    • TCA.EXE
    • TCM
    • TCM.EXE
    • TDS-3
    • TDS-3.EXE
    • TFAK
    • TFAK.EXE
    • vbcmserv
    • vbcmserv
    • vbcmserv.exe
    • vbcmserv.exe
    • VbCons
    • VbCons
    • VbCons.exe
    • VbCons.exe
    • VET32
    • VET32
    • VET32.exe
    • VET32.EXE
    • Vet95
    • VET95
    • Vet95.exe
    • VET95.EXE
    • VetTray
    • VETTRAY
    • VetTray.exe
    • VETTRAY.EXE
    • VIR-HELP
    • VIR-HELP.EXE
    • VPC32
    • VPC32.EXE
    • VPTRAY
    • VPTRAY.EXE
    • VSCHED
    • VSCHED.EXE
    • VSECOMR
    • VSECOMR
    • VSECOMR.EXE
    • VSECOMR.EXE
    • vshwin32
    • VSHWIN32
    • VSHWIN32
    • VSHWIN32.EXE
    • VSMAIN
    • VSMAIN.EXE
    • vsmon
    • vsmon.exe
    • VSMON.EXE
    • VSSTAT
    • VSSTAT
    • VSSTAT.EXE
    • WATCHDOG
    • WATCHDOG.EXE
    • WEBSCANX
    • WEBSCANX
    • WEBSCANX.EXE
    • WEBTRAP
    • WEBTRAP.EXE
    • WGFE95
    • WGFE95.EXE
    • WIMMUN32
    • WIMMUN32.EXE
    • WrAdmin
    • WRADMIN
    • WRADMIN
    • WrAdmin.exe
    • WRADMIN.EXE
    • WRADMIN.EXE
    • WrCtrl
    • WRCTRL
    • WRCTRL
    • WrCtrl.exe
    • WRCTRL.EXE
    • zapro
    • zapro.exe
    • zonealarm
    • zonealarm.exe
    • WINSERVICES
    • TCPSVS32
    • NAV32_LOADER
    • WINGATE.EXE
    • SYSHELP.EXE
    • WINMGM32.EXE
    • WINK
    • AAAA

  17. Performs a Denial of Service (DoS) attack to the following Web sites and some random hosts on ports 135, 139, and 445:
    • www.jamaat.org
    • www.klc.org.pk
    • www.pak.gov.pk
    • www.piac.com.pk
    • www.ummah.org.uk

  18. Scans the "%Windir%\INETPUB\WWWROOT" folder and overwrites all the files whose extension is "HTM" or "HTML," with the following text:

    <BR><BR><BR><CENTER><B><U> Ha..Ha..Haaa...</CENTER></U></B>

  19. Scans all the fixed and remote disks and all the shared folders and attempts to do the following:
    • Copy itself as Bind32.exe to the following folders
      • \WINDOWS
      • \WIN98
      • \WIN95
      • \WINNT
      • \WINME
      • \WINME
      • \WINXP

    • Add the following line to the [WINDOWS] section of the file \Windows\Win.ini, if the file exists:

      Run=BIND32.EXE

    • Copy itself as "\Documents and Settings\All Users\Start Menu\Programs\Startup\MSmgr.exe." The attribute of the file is set to read_only.

  20. Retrieves the KaZaA file-shared folder's location from the registry.

    The worm first renames any of the .com, .exe, or .scr files whose size is not less than the worm in this folder to .mp3, then it makes a copy of itself using the original file name. The worm appends some '00' bytes at the end of its copy. In this way, the worm copy has the same size as the original host file.

    For example, if C:\Program Files\KaZaA\My Shared Folder\test.exe exists, the worm may rename this file as test.mp3, and then copy itself as test.exe.

Email Routine Details
The worm uses its own SMTP engine to email itself to all the contacts in the Windows Address Book, MSN Messenger, .NET Messenger, Yahoo Pager, ICQ Pager, as well as in all the files whose extensions contain the letters HT. It attempts to use the default SMTP server of the infected computer to send mail. If the worm cannot find this information, then it will use one of the many SMTP server addresses, which are hard-coded into the worm. The email message has the following characteristics

Subject: Fw: Critical Patches
Attachment: MS-Q3946.EXE
Message:
Hi,
I got this mail from Microsot support. Atlast Microsoft has got a comprehensive patch
for all the vulnerabilities. Once this patch is applied, it takes care of all the recent virus problems
in Microsoft products.

Later....

Microsoft support wrote:

>Thanks for using Microsoft products. Recent viruses have prompted micrsoft to issue patches
>to all its customers worldwide.
>
>We are including a comprehensive patch for all windows platforms. This patch gives you
>comprehensive protection against all recent viruses.
>
>Yours sincerely,
>Kelly
>Team Support
>Microsoft Inc

Subject: Hi check your computer with this!!!
Attachment: FixBlast.com
Message:
Hi,

I am cutting and pasting the message i got from symantec antivirus
I think the last mail you sent me was infected with W32.Blaster.
Rgds

Dear customer,

We are enclosing Fix for both Welcha and Blaster worms as per your request.

Step by Step Instructions for Cleaning W32.Blaster/W32.Welcha Worms:

1. Save the file to a convenient location, such as your downloads folder or the Windows Desktop
2. To check the authenticity of the digital signature, refer to the section, "Digital signature."
3. Close all the running programs before running the tool.
4. If you are running Windows XP, then disable System Restore.
Refer to the section, "System Restore option in Windows Me/XP," for additional details.

In case of any clarifications please do not hesitate to contact us.

Best Regards,
Neil Thomas
Symantec Support

Subject: Your previous message is infected
Attachment: FixBlast.com
Message:
Hi,

Your previous mail to me is infected with Blaster.

I am attaching the tool i got from symantec site please clean your machine with the same.

Best Rgds,


Subject: Fix for New Worm Threat
Attachment: FixBlastz.com
Message:
Hi,

I got this mail from Mcafee Antivirus Support. There is a new variant of W32.Blaster worm.
I got a special fix today in the early hours, please check your machine with the attached tool.
I have also cut and pasted the steps for cleaning.

Rgds

Dear customer,

We are enclosing Fix for W32.Blaster.Z as per your request.

Step by Step Instructions for Cleaning W32.Blaster.Z

1. Save the file to a convenient location, such as your downloads folder or the Windows Desktop
2. To check the authenticity of the digital signature, refer to the section, "Digital signature."
3. Close all the running programs before running the tool.
4. If you are running Windows XP, then disable System Restore.
Refer to the section, "System Restore option in Windows Me/XP," for additional details.

In case of any clarifications please do not hesitate to contact us.

Best Regards,
Jerry Nelson
McAfee Support

From: Microsoft Support <support@microsoft.com>
Subject: Critical Updates
Attachment: MS-Q3526.com
Message:
Dear Customer,

Thanks for using Microsoft products. Recent viruses have prompted micrsoft to issue patches
to all its customers worldwide.

We are including a comprehensive patch for all windows platforms. This patch gives you
comprehensive protection against all recent viruses.

Yours sincerely,
JimThompson
Team Support
Microsoft Inc

person who registers
with us through your account, we will pay you $1.5.Once your account reaches
the limit of $50, your payment will be send to your registration address by
check or draft.

Please note that the registration process is completely free which means
by participating in this program you will only gain without loosing anything.

Best Regards,
Admin,

From : Symantec Support <support@symantec.com>
Subject : Fix for W32.Blaster/Welcha
Attachment : FixBlast.com
Message :
Dear customer,

We are enclosing Fix for both Welcha and Blaster worms as per your request.

Step by Step Instructions for Cleaning W32.Blaster/W32.Welcha Worms:

1. Save the file to a convenient location, such as your downloads folder or the Windows Desktop
(or removable media that is known to be uninfected, if possible).

2. To check the authenticity of the digital signature, refer to the section, "Digital signature."

3. Close all the running programs before running the tool.

4. If you are running Windows XP, then disable System Restore.
Refer to the section, "System Restore option in Windows Me/XP," for additional details.

In case of any clarifications please do not hesitate to contact us.

Best Regards,
Neil Thomas
Symantec Support

From : Mcafee Support <support@nai.com>
Subject : Fix for the latest W32/Blaster.Z
Attachment : Fixblastz.com
Message :
Dear customer,

We are enclosing Fix for W32.Blaster.Z as per your request.

Step by Step Instructions for Cleaning W32.Blaster.Z

1. Save the file to a convenient location, such as your downloads folder or the Windows Desktop
(or removable media that is known to be uninfected, if possible).

2. To check the authenticity of the digital signature, refer to the section, "Digital signature."

3. Close all the running programs before running the tool.

4. If you are running Windows XP, then disable System Restore.
Refer to the section, "System Restore option in Windows Me/XP," for additional details.

In case of any clarifications please do not hesitate to contact us.

Best Regards,
Jerry Nelson
McAfee Support

From: Microsoft Support <support@microsoft.com>
Subject: Critical Patches
Attachment: MS-Q31338.ZIP ( Which is a zip file that contains a copy of worm)
Message:
Dear Customer,

Thanks for using Microsoft products. Recent viruses have prompted micrsoft to issue patches
to all its customers worldwide.
We are including a comprehensive patch for all windows platforms. This patch gives you
comprehensive protection against all recent viruses.

Yours sincerely,.

JimThompson
Team Support
Microsoft Inc

From: System Administrator <admin@kpmg.com.com>
Subject: Fix for recent viruses
Attachment: FIXES.ZIP ( Which is a zip file that contains a copy of worm)
Message:
Hi All,

I am sending these fixes to the recent viruses which have been making rounds in the IT world.
I request you to install the same in your systems and pass it to others.

Yours sincerely,
James
System Administrator
KPMG

From: HRD Consultants <hr@consultants.com>
Subject: Your details
Attachment: Requirement.zip ( Which is a zip file that contains a copy of worm)
Message:
Hi,

We have your email id in our database. We have enclosed our requirements.

Expecting your reply at the earliest.

Kind Rgds,
James Martin

From: SymantecSupport <support@symantec.com>
Subject: Fix for W32.Blaster/W32.Welcha
Attachment: FixBlast.zip ( Which is a zip file that contains a copy of worm)
Message:
Dear customer,

We are enclosing Fix for both Welcha and Blaster worms as per your request.

Step by Step Instructions for Cleaning W32.Blaster/W32.Welcha Worms:

1. Save the file to a convenient location, such as your downloads folder or the Windows Desktop
(or removable media that is known to be uninfected, if possible). Extract from the zip file.

2. To check the authenticity of the digital signature, refer to the section, "Digital signature"

3. Close all the running programs before running the tool.

4. If you are running Windows XP, then disable System Restore.
Refer to the section, "System Restore option in Windows Me/XP," for additional details.

In case of any clarifications please do not hesitate to contact us.

Best Regards,
Keith Johnson
Symantec Support

From: McAfeeSupport <support@mcafee.com>
Subject: Fix for latest W32.Blaster.Zworm
Attachment: FixBlastz.zip ( Which is a zip file that contains a copy of worm)
Message:
Dear customer,

We are enclosing Fix for W32.Blaster.Z as per your request.

Step by Step Instructions for Cleaning W32.Blaster.Z

1. Save the file to a convenient location, such as your downloads folder or the Windows Desktop
(or removable media that is known to be uninfected, if possible).

2. To check the authenticity of the digital signature, refer to the section, "Digital signature"

3. Close all the running programs before running the tool.

4. If you are running Windows XP, then disable System Restore.
Refer to the section, "System Restore option in Windows Me/XP," for additional details.

In case of any clarifications please do not hesitate to contact us.

Best Regards,
Richard
McAfee Support

From: Support eEye <support@eeye.com>
Subject: Microsoft RPC still vulnerable - Latest worm
Attachment: RPCDCOM.ZIP ( Which is a zip file that contains a copy of worm)
Message:
Microsoft RPC Heap Corruption Vulnerability - Part II

Severity:
High (Remote Code Execution).

Description:
eEye Digital Security has discovered a critical remote vulnerability in the way Microsoft
Windows handles certain RPC requests.The RPC (Remote Procedure Call) protocol provides
an inter-process communication mechanism allowing a program running on one computer to execute code on a remote system. '
The vulnerability
exists within the DCOM (Distributed Component Object Model) RPC interface. This interface handles
DCOM object activation requests sent by client machines to the server. By sending a malformed
request packet it is possible to overwrite various heap structures and allow the execution of
arbitrary code.

Please install the attached patch immediately.

Subject: Details.
Attachment: details.pif ( Which is a zip file that contains a copy of worm)
Message:
Hi,

See the attached file for details.

Rgds

Subject: Thank you
Attachment: thankyou.zip ( Which is a zip file that contains a copy of worm)
Message:
Please see the attached file for details

Rgds

Subject: Your document
Attachment: your_documents.zip ( Which is a zip file that contains a copy of worm)
Message:
See the attached file for your documents

Rgds

Subject: Your application
Attachment: application.zip ( Which is a zip file that contains a copy of worm)
Message:
Please see the attached file for applicaion details.

Rgds

Subject: Wicked Screen Saver
Attachment: wickedsaver.zip ( Which is a zip file that contains a copy of worm)
Message:
Hi,

This is the most wicked screen saver i have ever seen.Enjoy!!!'

Rgds

Subject: Naughty Movie Clip
Attachment: movie3498.zip ( Which is a zip file that contains a copy of worm)
Message:
Hi,

This is an interesting movie clip. You will enjoy it.

Rgds

Subject: Hi check your computer with this!!!
Attachment: FixBlast.zip ( Which is a zip file that contains a copy of worm)
Message:
Hi,

I am cutting and pasting the message i got from symantec antivirus
I think the last mail you sent me was infected with W32.Blaster.

Bye

Dear customer,

We are enclosing Fix for both Welcha and Blaster worms as per your request.

Step by Step Instructions for Cleaning W32.Blaster/W32.Welcha Worms:

1. Save the file to a convenient location, such as your downloads folder or the Windows Desktop
2. To check the authenticity of the digital signature, refer to the section, "Digital signature."

3. Close all the running programs before running the tool.
4. If you are running Windows XP, then disable System Restore.

In case of any clarifications please do not hesitate to contact us.

Best Regards,
Neil Thomas
Symantec Support

Subject: I got an infected mail from you
Attachment: FixBlast.zip ( Which is a zip file that contains a copy of worm)
Message:
Hi,

Your previous mail to me is infected with Blaster.

I am attaching the tool i got from symantec site please clean your machine with the same.

Best Rgds,


Subject: Fix for New Worm Threat.
Attachment: FixBlastz.zip ( Which is a zip file that contains a copy of worm)
Message:
Hi,

I got this mail from Mcafee Antivirus Support. There is a new variant of W32.Blaster worm.
I got a special fix today in the early hours, please check your machine with the attached tool.
I have also cut and pasted the steps for cleaning.

Rgds


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: Yana Liu

Discovered: October 22, 2003
Updated: February 13, 2007 12:12:44 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. Edit the registry and reverse the changes that the worm made.
  2. Disable System Restore (Windows Me/XP).
  3. Updating the virus definitions.
  4. Run a full system scan and delete the files that are detected as W32.Yaha.AE@mm and Keylogger.Trojan.
  5. Restore the following files from a clean backup if the worm overwrote them, or simply delete them, if infected:
    %Windir%\Hosts
    %Windir%\Lmhosts
    %System\etc\hosts
    %System\etc\Lmhosts

  6. Delete the file, %System%\SCHED32.dll.
  7. Remove the following line in the [Windows] section of the file Win.ini:

    run=REGE32.EXE

1. Editing the registry and reversing the changes


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.

Before repairing the registry, first re-enable the registry tools.
  1. Click Start, then Run. (The Run dialog box appears.)
  2. Type notepad

    and click OK. (Notepad opens a text file.)
  3. Type, or copy and paste, the following text into the text file:

    REGEDIT4

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

    "DisableRegistryTools"=dword:00000000

    [HKEY_CLASSES_ROOT\batfile\shell\open\command]
    @="\"%1\" %*"

    [HKEY_CLASSES_ROOT\comfile\shell\open\command]
    @="\"%1\" %*"

    [HKEY_CLASSES_ROOT\exefile\shell\open\command]
    @="\"%1\" %*"

    [HKEY_CLASSES_ROOT\piffile\shell\open\command]
    @="\"%1\" %*"

    [HKEY_CLASSES_ROOT\scrfile\shell\open\command]
    @="\"%1\" %*"
  4. Save the file as repair.reg in the root folder (usually C:\).
  5. Click Start, then Run.
  6. Type regedit -s \repair.reg

    and click OK.
  7. Click Start, and then click Run.
  8. Type regedit

    Then click OK. (The Registry Editor opens.)
  9. Navigate to each of the following keys:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
  10. In the right pane, delete the value:

    "MS Explorer"="%System%\mexplore.exe"
  11. Navigate to each of the following keys and delete them, if exist:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RedWorm
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Winver
    HKEY_LOCAL_MACHINE\Winver
  12. Exit the Registry Editor.


2. 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 you are satisfied that the threat has been removed, you should reenable 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. 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.


4. 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.Yaha.AE@ or Keylogger.Trojan, click Delete.

5. Restoring the files
Restore the following files from a clean backup if the worm overwrote them, or simply delete them if they were infected:
%Windir%\Hosts
%Windir%\Lmhosts
%System\etc\hosts
%System\etc\Lmhosts

6. Deleting the file, %System%\SCHED32.dll
Use Windows Explorer to do this.


7. Editing the Win.ini file
If you are running Windows 95/98/Me, follow these steps:
  1. The function you perform depends on your operating system:
    • Windows 95/98: Go to step B.
    • Windows Me: If you are running Windows Me, the Windows Me file-protection process may have made a backup copy of the Win.ini file that you need to edit. If this backup copy exists, it will be in the C:\Windows\Recent folder. Symantec recommends that you delete this file before continuing with the steps in this section. To do this:
      1. Start Windows Explorer.
      2. Browse to and select the C:\Windows\Recent folder.
      3. In the right pane, select the Win.ini file and delete it. The Win.ini file will be regenerated when you save your changes to it in step F.

  2. Click Start, and then click Run.
  3. Type the following, and then click OK.

    edit c:\windows\win.ini

    (The MS-DOS Editor opens.)

    NOTE: If Windows is installed in a different location, make the appropriate path substitution.

  4. In the [windows] section of the file, look for a line similar to:

    Run=BIND32.EXE

  5. If this line exists, delete everything to the right of Run=.

    When you are done, it should look like:

    Run=

  6. Click File, and then click Save.
  7. Click File, and then click Exit.


Writeup By: Yana Liu