W32.Gaobot.AOL

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Discovered: June 04, 2004
Updated: February 13, 2007 12:24:02 PM
Type: Worm
Systems Affected: Windows


W32.Gaobot.AOL is a worm that spreads through open network shares and several Windows vulnerabilities. The vulnerabilities are:


The worm can act as a backdoor and attack other computers. It also attempts to kill the processes of many antivirus and security programs.

Antivirus Protection Dates

  • Initial Rapid Release version June 04, 2004
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version June 04, 2004
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date June 07, 2004

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

Writeup By: Paul Mangan

Discovered: June 04, 2004
Updated: February 13, 2007 12:24:02 PM
Type: Worm
Systems Affected: Windows


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

  1. Copies itself to the %System% folder as lrbz32.exe.


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

  2. Adds the value:

    "MS Config v13"="lrbz32.exe"

    to following registry keys:

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

    so that the worm runs when Windows starts.

  3. Attempts to terminate the processes of a large number of antivirus and security applications. See the Processes section for a complete list.

  4. Attempts to delete files associated with other worms, delete the registry key entries referring to these worms, and terminate processes with the following names:
    • winhlpp32.exe
    • tftpd.exe
    • dllhost.exe
    • winppr32.exe
    • mspatch.exe
    • penis32.exe
    • msblast.exe

  5. Connects to a remote IRC server and awaits commands from a remote attacker.

    The backdoor allows an attacker to perform the following actions on the compromised system:
    • Run commands
    • Retrieve files through FTP and HTTP
    • Retrieve data from the registry
    • Restart the computer
    • List the processes
    • Kill a particular process
    • Terminate Windows services
    • Perform HTTP, ICMP, SYN, and UDP floods
    • Retrieve the email addresses stored on the computer
    • Retrieve a list of email addresses through HTTP
    • Retrieve a given URL
    • Sniff HTTP, FTP, and IRC traffic
    • Steal the Windows product ID and the CD keys of various video games
    • Send spam to the Windows Messenger service of another computer

  6. Attempts to propagate to other IP addresses using the following methods:
  7. Attempts to authenticate itself to the following remote SMB shares:
    • admin$
    • print$
    • c$
    • d$
    • e$
    • c

      using the following usernames and passwords:

      Usernames:
    • aaa
    • abc
    • Admin
    • admin
    • Administrador
    • Administrateur
    • administrator
    • Administrator
    • asdf
    • Convidado
    • Coordinatore
    • Default
    • Dell
    • Gast
    • Guest
    • home
    • Inviter
    • mgmt
    • Ospite
    • Owner
    • qwer
    • Standard
    • temp
    • Test
    • User
    • Verwalter
    • win
    • xyz

      Passwords:
    • 000000
    • 00000000
    • 007
    • 110
    • 111
    • 111111
    • 11111111
    • 121212
    • 123
    • 123123
    • 1234
    • 12345
    • 123456
    • 1234567
    • 12345678
    • 123456789
    • 1234qwer
    • 123abc
    • 123asd
    • 123qwe
    • 2002
    • 2600
    • 54321
    • 654321
    • 88888888
    • abcd
    • alpha
    • computer
    • database
    • enable
    • foobar
    • god
    • godblessyou
    • ihavenopass
    • Internet
    • Login
    • love
    • mypass
    • mypc
    • oracle
    • owner
    • pass
    • passwd
    • Password
    • password
    • pat
    • patrick
    • pwd
    • root
    • secret
    • server
    • sex
    • super
    • sybase
    • xxx
    • yxcv
    • zxcv
  8. Copies itself to any remote shares to which it successfully authenticates, and the schedules a network job to run the worm on the remote computer.

Processes
W32.Gaobot.AOL attempts to end the following processes:
  • _AVP32.EXE
  • _AVPCC.EXE
  • _AVPM.EXE
  • ACKWIN32.EXE
  • ANTI-TROJAN.EXE
  • APVXDWIN.EXE
  • AUTODOWN.EXE
  • AVCONSOL.EXE
  • AVE32.EXE
  • AVGCTRL.EXE
  • AVKSERV.EXE
  • AVNT.EXE
  • AVP.EXE
  • AVP32.EXE
  • AVPCC.EXE
  • AVPDOS32.EXE
  • AVPM.EXE
  • AVPTC32.EXE
  • AVPUPD.EXE
  • AVSCHED32.EXE
  • AVWIN95.EXE
  • AVWUPD32.EXE
  • BLACKD.EXE
  • BLACKICE.EXE
  • CFIADMIN.EXE
  • CFIAUDIT.EXE
  • CFINET.EXE
  • CFINET32.EXE
  • CLAW95.EXE
  • CLAW95CF.EXE
  • CLEANER.EXE
  • CLEANER3.EXE
  • DVP95.EXE
  • DVP95_0.EXE
  • ECENGINE.EXE
  • ESAFE.EXE
  • ESPWATCH.EXE
  • F-AGNT95.EXE
  • FINDVIRU.EXE
  • FPROT.EXE
  • F-PROT.EXE
  • F-PROT95.EXE
  • FP-WIN.EXE
  • FRW.EXE
  • F-STOPW.EXE
  • IAMAPP.EXE
  • IAMSERV.EXE
  • IBMASN.EXE
  • IBMAVSP.EXE
  • ICLOAD95.EXE
  • ICLOADNT.EXE
  • ICMON.EXE
  • ICSUPP95.EXE
  • ICSUPPNT.EXE
  • IFACE.EXE
  • IOMON98.EXE
  • JEDI.EXE
  • LOCKDOWN2000.EXE
  • LOOKOUT.EXE
  • LUALL.EXE
  • MOOLIVE.EXE
  • MPFTRAY.EXE
  • N32SCANW.EXE
  • NAVAPW32.EXE
  • NAVLU32.EXE
  • NAVNT.EXE
  • NAVW32.EXE
  • NAVWNT.EXE
  • NISUM.EXE
  • NMAIN.EXE
  • NORMIST.EXE
  • NUPGRADE.EXE
  • NVC95.EXE
  • OUTPOST.EXE
  • PADMIN.EXE
  • PAVCL.EXE
  • PAVSCHED.EXE
  • PAVW.EXE
  • PCCWIN98.EXE
  • PCFWALLICON.EXE
  • PERSFW.EXE
  • RAV7.EXE
  • RAV7WIN.EXE
  • RESCUE.EXE
  • SAFEWEB.EXE
  • SCAN32.EXE
  • SCAN95.EXE
  • SCANPM.EXE
  • SCRSCAN.EXE
  • SERV95.EXE
  • SMC.EXE
  • SPHINX.EXE
  • SWEEP95.EXE
  • TBSCAN.EXE
  • TCA.EXE
  • TDS2-98.EXE
  • TDS2-NT.EXE
  • VET95.EXE
  • VETTRAY.EXE
  • VSCAN40.EXE
  • VSECOMR.EXE
  • VSHWIN32.EXE
  • VSSTAT.EXE
  • WEBSCANX.EXE
  • WFINDV32.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: Paul Mangan

Discovered: June 04, 2004
Updated: February 13, 2007 12:24:02 PM
Type: Worm
Systems Affected: Windows


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

  1. Disable System Restore (Windows Me/XP).
  2. Update the virus definitions.
  3. Restart the computer in Safe mode or VGA mode.
  4. Run a full system scan and delete all the files detected as W32.Gaobot.AOL.
  5. Reverse the changes made to the registry.
For 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 on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).

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

3. To restart the computer in Safe mode or VGA mode
Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode or VGA mode.
  • For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
  • For Windows NT 4 users, restart the computer in VGA mode.
4. To scan for and delete the infected files
5. Reversing the changes made to the registry


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

      Then click OK. (The Registry Editor opens.)

    3. Navigate to the keys:

      HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
      HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
      RunServices

    4. Delete the value:

      "MS Config v13"="lrbz32.exe"

    5. Exit the Registry Editor.


Writeup By: Paul Mangan