Threat Explorer

The Threat Explorer is a comprehensive resource consumers can turn to for daily, accurate, up-to-date information on the latest threats, risks and vulnerabilities.



22 August 1995
13 February 2007
Also Known As:
UNashamed_Naked, Naked

The Unashamed virus is a simple master boot record, floppy boot sector infecting virus that tries to hide itself using a common technique called stealthing, which causes the system to point to a clean copy of the infected area rather then the infected area itself (this would be seen when you try to view the hard drive with a disk editing program and the virus is active in memory). Systems infected with this virus will report a loss of 2k in total conventional memory.

Contained within the body of the virus is the following encrypted text, which is never displayed to the screen (this virus contains the code to display the text below; however, the test condition always fails):

    the UNashamed Naked!

On infected hard drives, a copy of the original master boot record is stored at physical location cylinder 0 side 0 sector 14.


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.

Please read all instructions before you begin.

  • The procedure described in this document could result in the loss of all data on the computer if not done correctly. Unless you are completely familiar with the use of the DOS FDISK command, we suggest that you obtain the services of a qualified computer consultant.
  • If your computer uses a Dynamic Drive Overlay, or if you are not sure, first follow the instructions in the document How to repair a virus when using a dynamic drive overlay or a disk compression utility.
To remove the virus:
  1. Shut down Windows, and then turn off the power. Do not simply press the reset button.
  2. Wait 30 seconds for memory to be cleared.
  3. Insert an uninfected, write-protected, bootable disk that also contains the FDISK program into the floppy disk drive, and then restart the computer.
  4. Type the following, and then press Enter:

    fdisk /mbr
  5. Remove the floppy disk, and then restart the computer.
  6. Start Norton AntiVirus, and run a full system scan.

Writeup By: SARC Engineer