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Updated: February 13, 2007 12:57:29 PM
Type: Trojan Horse
Systems Affected: Windows

Bloodhound.SONAR.2 is used exclusively by Symantec antivirus products when a potentially unknown risk is found using Symantec Bloodhound technology. Bloodhound technology consists of heuristic algorithms that are used to detect unknown risks.

Antivirus Protection Dates

  • Initial Rapid Release version July 06, 2006
  • Latest Rapid Release version July 06, 2006
  • Initial Daily Certified version July 06, 2006
  • Latest Daily Certified version July 06, 2006

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

Technical Description

The file that is detected under Bloodhound.SONAR.2 indicates a running process with behavior similar to that of a Trojan horse that records keystrokes. It may represent a new, previously unidentified type of risk. This assessment is made using the state-of-the-art behavioral technology that is only available in Symantec products. Files that are detected as Bloodhound.Sonar.2 should be submitted to Symantec Security Response.

Submitting a sample to Symantec Security Response
Please submit files that are detected as Bloodhound.SONAR.2 to Symantec Security Response so that these new risks or variants can be identified and assigned specific names. To learn how to submit a file, read the document for the type of Symantec antivirus product that you are using:

    • Consumer products

      If you are using a Symantec consumer antivirus product, such as Norton AntiVirus 2007, click here.

    • Enterprise products

      If you are using a Symantec enterprise (corporate) antivirus product, such as Symantec AntiVirus Corporate Edition 11.0, click here.

Removing a file from Quarantine
It is possible to restore a file from quarantine to its previous location on your computer. This should only be done if you are certain that the file is not malicious. Symantec strongly recommend that you submit the file that was detected as Bloodhound.Sonar.2 even if you choose to restore the file from quarantine. To learn how to restore a file from quarantine using Norton AntiVirus 2007, click here .


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.