Home / malware Backdoor:W32/IRCBot.ET
First posted on 19 October 2009.
Source: SecurityHomeAliases :
There are no other names known for Backdoor:W32/IRCBot.ET.
Explanation :
A remote administration utility which bypasses normal security mechanisms to secretly control a program, computer or network.
Additional DetailsBackdoor:W32/IRCBot.ET is a variant of a bot that spreads by exploiting the known Plug and Play service (MS05-039) vulnerability. It is a packed PE executable file 51326 bytes long.
The bot was first found on August, 16th 2005.
Installation
When run, the worm copies under %SYSTEM% directory using the name 'windrg32.exe'. Then it adds the following registry entries to ensure that it is started when a user logs on or the system is restarted:
  • [HKLMSOFTWAREMicrosoftWindowsCurrentVersionRun]
"winDrg32" = "windrg32.exe"
Propagation
The worm scans for systems vulnerable to Microsoft Windows Plug and Play service (MS05-039) through TCP/445. Please see the following page for detailed information on the vulnerability: http://www.microsoft.com/technet/security/Bulletin/MS05-039.mspx
The following ports are used in attack:
  • Port 445: The worm scans for systems vulnerable to PnP exploit through this port   • Port 29463: FTP server port on infected systems   • Port 6667: The command shell port opened by the exploit code.
Activity
The worm tries to connect to IRC channel at predefined address. The attacker who knows channel password can instruct the bot to execute the following actions:
  • Disconnect/reconnect from the IRC channel   • Request system information   • Download and execute files   • Remove worm from the system   • Manipulate system security settings
IRCBot.ET also tries to uninstall some other malware and adware by deleting files and folders and removing registry keys.
The worm tries to terminates the following processes:
  • botzor.exe (Net-Worm.Win32.Mytob.cd / Zotob.A)   • CMESys.ex   • csm.exe (Net-Worm.Win32.Mytob.cf / Zotob.B)   • CxtPls.exe   • NHUpdater.exe   • pnpsrv.exe (Backdoor.Win32.Rbot.yk   • qttask.exe   • realsched.exe   • ViewMgr.exe   • winpnp.exe (Backdoor.Win32.Rbot.ym)Last update 19 October 2009