Hacktool.DoS

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Discovered: February 11, 2002
Updated: February 13, 2007 11:38:14 AM
Type: Trojan Horse
Systems Affected: Windows



Hacktool.DoS is a hacktool that performs a Denial of Service (DoS) attack against a third-party server.

Even though this tool does not cause any damage to the computer on which it is deployed, it is considered a threat by network administrators.

Antivirus Protection Dates

  • Initial Rapid Release version February 13, 2002
  • Latest Rapid Release version May 07, 2018 revision 017
  • Initial Daily Certified version February 13, 2002 revision 036
  • Latest Daily Certified version May 07, 2018 revision 024
  • Initial Weekly Certified release date February 13, 2002

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

Writeup By: Atli Gudmundsson

Discovered: February 11, 2002
Updated: February 13, 2007 11:38:14 AM
Type: Trojan Horse
Systems Affected: Windows


The deployment of this tool usually results in a slowdown of the server that is being attacked. Under some conditions it may cause the server to stop responding. Rebooting the afflicted server will not terminate the attack; only by terminating the hacktool will the attack be stopped.

Because network administrators and Internet Service Providers (ISPs) can often track down where an attack is coming from, hackers often use this kind of tool from a zombie or a drone computer.

A zombie or drone computer is so named because the owner of that computer usually does not know that their computer is being used in this manner.

Zombies or drones are usually acquired by hackers by sending the unsuspecting user of that computer a Backdoor Trojan , which can be used to gain complete control over that computer. Another way to acquire zombies or drones is to use known backdoors that are implemented by worms that have already spread, such as CodeRed II .

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.

Writeup By: Atli Gudmundsson

Discovered: February 11, 2002
Updated: February 13, 2007 11:38:14 AM
Type: Trojan Horse
Systems Affected: Windows


Obtain the most recent virus definitions. There are two ways to do this:

    • Run LiveUpdate. LiveUpdate is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
    • Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions have undergone full quality assurance testing by Symantec Security Response. They are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.

      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.
  1. Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files. For instructions on how to do this, read the document How to configure Norton AntiVirus to scan all files.
  2. Run a full system scan.
  3. Delete all files that are detected as Hacktool.DoS.


Writeup By: Atli Gudmundsson