W32.HLLW.Gaobot.BF

When W32.HLLW.Gaobot.BF is executed, it peforms the following actions:

1. Copies itself as %System%\wincrt32.exe.

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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).

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2. Adds the value:

"Configuration Loader"="%System%\wincrt32.exe"

to the registry keys:

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

so that the worm runs when you start Windows.

3. Connects to a predefined IRC channel, using its own IRC client, and listens for the commands from a hacker.


4. Allows a hacker to remotely control a compromised computer, allowing him/her to perform any of the following actions:

• Manage the installation of the worm
• Dynamically update the installed worm
• Download and execute files
• Steal system information
• Send the worm to other IRC users
• Add new accounts

5. Schedules a Network Job to run the worm.


6. Performs Distributed Denial of Service (DDoS) attacks against targeted systems, of which IP addresses are randomly calculated.


7. Acts as a proxy server to direct attacks to another machine.


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


9. Probes the following shares:

• admin$
• c$
• d$
• e$
• print$
• c
  
  using the following usernames and passwords, as well as any usernames found using NetUserEnum():
  
  User
  
  Administrator
  Administrateur
  Coordinatore
  Administrador
  Verwalter
  Ospite
  admin
  administrator
  Default
  Convidado
  mgmt
  Standard
  User
  Administrador
  Owner
  Test
  Guest
  Gast
  Inviter
  a
  aaa
  abc
  x
  xyz
  Dell
  home
  pc
  test
  temp
  win
  asdf
  qwer
  login
  
  Password
  
  admin
  Admin
  password
  Password
  1
  12
  123
  1234
  12345
  123456
  1234567
  12345678
  123456789
  654321
  54321
  111
  000000
  00000000
  11111111
  88888888
  pass
  passwd
  database
  abcd
  oracle
  sybase
  123qwe
  server
  computer
  Internet
  super
  123asd
  ihavenopass
  godblessyou
  enable
  xp
  2002
  2003
  2600
  110
  111111
  121212
  123123
  1234qwer
  123abc
  007
  alpha
  patrick
  pat
  administrator
  root
  sex
  god
  foobar
  a
  aaa
  abc
  test
  temp
  win
  pc
  asdf
  secret
  qwer
  yxcv
  zxcv
  home
  xxx
  owner
  login
  Login
  pwd
  pass
  love
  mypc
  mypass
  pw
  
  

10. Copies itself to any systems it compromised using the aforementioned exploits.


11. Steals the CD keys of the following games:

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

12. Ends the following processes that are associated with antivirus and firewall software:

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

13. Attemps to kill some processes associated with other worms:

• dllhost.exe
• msblast.exe
• mspatch.exe
• penis32.exe
• scvhosl.exe
• tftpd.exe
• winhlpp32.exe
• winppr32.exe

14. Listens on randomly calculated ports, a few of range between 1000 and 3000, and one from above 10000, and waits for other computers to download the worm.

Recommendations

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

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

Summary