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Discovered: March 10, 2003
Updated: February 13, 2007 11:44:09 AM
Also Known As: IRC/Flood.ap [McAfee], W32/Randon.worm [KAV], Randon [F-Secure], Q8Hell, W32.Rondon
Type: Trojan Horse, Worm
Systems Affected: Windows

Backdoor.IRC.Aladinz.B is an IRC-based Trojan that attempts to spread through Windows NT/2000/XP networks.

Antivirus Protection Dates

  • Initial Rapid Release version March 11, 2003
  • Latest Rapid Release version August 08, 2016 revision 023
  • Initial Daily Certified version March 11, 2003
  • Latest Daily Certified version August 09, 2016 revision 001
  • Initial Weekly Certified release date March 12, 2003

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

Technical Description

Backdoor.IRC.Aladinz.B is composed of the following components:

  • Deta.exe, which is a utility used to hide windows. It is 19,968 bytes.
  • Psexec.exe, which is a remote execution utility. It is 37,376 bytes.
  • Libparse.exe, which is a process viewer. It is 25,600 bytes.
  • Systrey.exe, which is an mIRC client program. It is 562,688 bytes.

    NOTE: The aforementioned files are all UPX-packed and are not viral. Because they are not are not malicious, Symantec antivirus products do not detect them as such.

  • Reader.w, which is a text file that contains many nicknames. It is 105,374 bytes.
  • Rconnect.conf, which has its attribute set to Hidden. This is detected as Backdoor.IRC.Aladinz.B. It is 315 bytes.
  • Rcfg.ini, which is a .ini file used by the worm to load other IRC scripts, such as:
    • fControl.a, which is an IRC script. It is detected as IRC Trojan.
    • IfControl.a, which is an IRC script. It is detected as IRC Trojan.
    • scontrol.a, which is an IRC script. It is detected as IRC Trojan.
    • a.a, which is an IRC script. It is detected as Backdoor.IRC.Aladinz.B and is 40 bytes.
    • b.a, which is an IRC script. It is 97 bytes.

      Rcfg.ini is detected as Backdoor.IRC.Aladinz.B and is 2,432 bytes.

      Backdoor.IRC.Aladinz.B uses these script files to find an open TCP port 445 on randomly generated IP addresses. If successful, it sends its components to other IRC users, or it performs a Denial of Service (DoS) attack.

  • Incs.bat, which is a Trojan batch file. Backdoor.IRC.Aladinz.B uses this batch file to connect to remote IPC$ shares on each of the IP addresses it finds, using various user name and password pairs. It is 1,854 bytes.

    For example, Incs.bat may try the user name, "Administrator," with these passwords:
    • <blank>
    • admin
    • Administrator
    • test
    • test123
    • temp
    • temp123
    • pass
    • password
    • changeme

      If Incs.bat is successful, it opens the Sencs.bat file.

  • Sencs.bat, which is a batch file that copies Sa.exe to remote network shares. This is detected as Backdoor.IRC.Aladinz.B. It is 2,941 bytes.
  • Sa.exe, which is a Win32 executable file that downloads the Backdoor.IRC.Aladinz.B installer from some predefined Web sites. This is detected as Backdoor.IRC.Aladinz.B.
  • The Backdoor.IRC.Aladinz.B installer. This is about 74 KB, depending on the variant. The file name can be one of the following:
    • Azas.exe
    • Secs.exe
    • Ali.exe
    • Ao.exe
    • Fr.exe
    • Genah.exe
    • Get.exe
    • T3st.exe

      The installer is detected as Backdoor.IRC.Aladinz.B.
When the installer is executed, it does the following:
  1. Creates one of the following folders, depending on the variant:
    • %System%\zx
    • %System%\zx1

      NOTE: %System% is a variable. The Backdoor.IRC.Aladinz.B installer locates the Windows system folder and creates the folders in 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).

      Then, the installer drops all the components into that folder.

  2. Creates the subkey, OBCD, in the registry:


    and adds the following values to this subkey:

    DisplayName mIRC
    UninstallString %System%\<the subfolder, for example, zx>\systrey.exe -install
  3. Adds the value:

    UpdateWins %System%\<the subfolder, for example, zx>\systrey.exe

    to the registry key:


    so that the mIRC client program runs each time you start Windows, causing the script components of Backdoor.IRC.Aladinz.B to run as well.


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.


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

  1. Update the virus definitions.
  2. Run a full system scan.
    • Delete all the files detected as Backdoor.IRC.Aladinz.B, IRC Trojan, or Bat.Trojan.
    • Manually delete Reader.w and b.a.
  3. Delete the value and key added to the registry key.
For specific details on each of these steps, read the following instructions.

1. 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 here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

2. 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 Backdoor.IRC.Aladinz.B, IRC Trojan, or Bat.Trojan, click Delete.
  4. Use Windows Explorer to delete the files, Reader.w and b.a.

3. Deleting the value from the registry

CAUTION : Symantec strongly recommends that you back up the registry before you make 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, and then click OK. (The Registry Editor opens.)
  3. Navigate to the key:

  4. In the right pane, delete the value:

    UpdateWins %System%\<the subfolder, for example, zx>\systrey.exe
  5. Navigate to the following key and delete it:

  6. Click Registry, and then click Exit.

Writeup By: Yana Liu