1. Symantec/
  2. Security Response/
  3. Bloodhound


Risk Level 1: Very Low

February 13, 2007 11:50:01 AM

Norton AntiVirus (NAV) has the ability to detect unknown viruses of various types using heuristic algorithms known as Bloodhound. This technology was developed by Symantec Security Response.

Addition information on Bloodhound.AOLPWS detections
When Norton AntiVirus detects a Bloodhound.AOLPWS Trojan horse program, it indicates the offending file by name. The file has different names depending on the version of the Trojan. Symantec Technical Support has encountered the following Trojan files to date:

Explore.exe (not Explorer.exe)
PKg5184.exe (This Trojan asks for credit card information.)
Setup.pkg (This file name is also used by some installation programs. Use caution in deleting it.)

Many of these files are named in such a way as to trick the unsuspecting user into thinking that they are Windows system files, and thus deter their removal. The Win.ini or System.ini files may also be marked read-only, making it difficult to remove the commands placed there by the Trojan.

To locate and remove Bloodhound.AOLPWS Trojans, follow these steps:

CAUTION: Because of the large number of these Trojans, these instructions are somewhat general, and by necessity, assume that you are familiar with the operating system and the use of Windows utilities such as the System Editor. If you are not, please contact a qualified computer consultant.

Locate the named Trojan program
  1. Click Start, point to Find, and click Files or Folder.
  2. Type the name of the file, and then press Enter.
  3. Right-click the file in the results pane, and click Delete.

Remove references to the Trojan from the Win.ini and System.ini files
  1. Click Start, and click Run.
  2. Type sysedit and then press Enter. The System Configuration Editor appears.
  3. Click the window titled C:\WINDOWS\WIN.INI.
  4. Beneath the [Windows] section, remove any references to the Trojan from the load= and run= lines.
  5. Click the window titled C:\WINDOWS\SYSTEM.INI.
  6. Beneath the [boot] section, the shell= line should read shell=explorer.exe

    NOTE: Some vendors, such as Compaq, may include a custom shell. In the case of a Compaq computer, this may read shell=cpqshell.exe. If in doubt, contact your vendor.
  7. Exit the System Configuration Editor, and click Yes when you are prompted to save changes.

    NOTE: If the read-only attribute is set for the Win.ini and System.ini files, then you will need to remove that attribute before you can save the files.

Remove references to the Trojan from the registry
These Trojans can load from the registry, and they need to be removed from the \Run key:

CAUTION: We strongly recommend that you back up the system registry before making any changes. Incorrect changes to the registry could result in permanent data loss or corrupted files. Please make sure you modify only the keys specified. Please see the document How to back up the Windows registry before proceeding.
  1. Click Start, and click Run. The Run dialog box appears.
  2. Type regedit and then click OK.
  3. Navigate to the following key:

  4. In the right pane, delete the value that refers to the Trojan.
  5. Close the Registry Editor. Any changes that you made are saved automatically.

Check the StartUp Folder
Some Trojans load from the Windows StartUp folder. Please follow these steps remove them:
  1. Click Start, point to Settings, and click Taskbar.
  2. Click the Start Menu Programs tab.
  3. Click Advanced, open the Programs folder, and then open the StartUp folder.
  4. In the right pane, locate the file that you want to remove (for example, System.exe), and select it. This may be the actual file, or a shortcut to it.
  5. Click the Edit menu, and click Cut.
  6. Open a folder of your choice into which you want to move the file or shortcut.
  7. Click the Edit menu, and click Paste.
  8. Close the window, click OK, and then restart the computer.

    NOTE: If you are sure that you do not need the file that is in the StartUp folder--by design, these should be shortcuts, rather than program files--you can delete them instead of moving them.

CAUTION: Because your password could have been compromised, we strongly recommend that you contact AOL customer service and change your password before you log back on.

Antivirus Protection Dates

  • Initial Rapid Release version December 19, 2000
  • Latest Rapid Release version February 17, 2018 revision 003
  • Initial Daily Certified version December 19, 2000
  • Latest Daily Certified version February 18, 2018 revision 001
  • Initial Weekly Certified release date pending
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.
Writeup By: Motoaki Yamamura

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