Symantec Security Response encourages all users and administrators to adhere
to the following basic security "best practices":
a.. Turn off and remove unneeded services. By default, many operating
systems install auxiliary services that are not critical, such as an FTP
server, telnet, and a Web server. These services are avenues of attack. If
they are removed, blended threats have less avenues of attack and you have
fewer services to maintain through patch updates.
b.. If a blended threat exploits one or more network services, disable, or
block access to, those services until a patch is applied.
c.. 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.
d.. 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.
e.. Configure your email server to block or remove email that contains
file attachments that are commonly used to spread viruses, such as .vbs,
..bat, .exe, .pif and .scr files.
f.. Isolate infected computers quickly to prevent further compromising
your organization. Perform a forensic analysis and restore the computers
using trusted media.
g.. 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.
The following instructions pertain to all current and recent Symantec
antivirus products, including the Symantec AntiVirus and Norton AntiVirus
product lines.
1.. Disable System Restore (Windows Me/XP).
2.. Update the virus definitions.
3.. Restart the computer in Safe mode.
4.. Run a full system scan and delete all the files detected as
W32.Spybot.Worm.
5.. Delete the value that was added to the registry.
6.. Delete any zero-byte files in the startup folder.
For specific details on each of these steps, read the following
instructions.
1. Disabling System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you
temporarily turn off System Restore. Windows Me/XP uses this feature, which
is enabled by default, to restore the files on your computer in case they
become damaged. If a virus, worm, or Trojan infects a computer, System
Restore may back up the virus, worm, or Trojan on the computer.
Windows prevents outside programs, including antivirus programs, from
modifying System Restore. Therefore, antivirus programs or tools cannot
remove threats in the System Restore folder. As a result, System Restore has
the potential of restoring an infected file on your computer, even after you
have cleaned the infected files from all the other locations.
Also, a virus scan may detect a threat in the System Restore folder even
though you have removed the threat.
For instructions on how to turn off System Restore, read your Windows
documentation, or one of the following articles:
a.. "How to disable or enable Windows Me System Restore"
b.. "How to turn off or turn on Windows XP System Restore"
For additional information, and an alternative to disabling Windows Me
System Restore, see the Microsoft Knowledge Base article, "Antivirus Tools
Cannot Clean Infected Files in the _Restore Folder," Article ID: Q263455.
2. 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:
a.. 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).
b.. 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: Read "How to
update virus definition files using the Intelligent Updater" for detailed
instructions.
3. Restarting the computer in Safe mode
Restart the computer in Safe mode. All the Windows 32-bit operating systems,
except for Windows NT, can be restarted in Safe mode.
NOTE: The following instructions are basic and can vary slightly depending
on the operating system.
1.. If the computer is running, shut down Windows and then turn off the
power.
2.. Wait 30 seconds, and then turn on the computer.
3.. Start tapping the F8 key.
4.. When the Startup Menu appears, ensure that the Safe mode option is
selected. In most cases, it is the first item in the list and is selected by
default. (If it is not selected, use the arrow keys to select it.)
5.. Press Enter. The computer will start in Safe mode. This can take a few
minutes.
6.. When you are finished with all the troubleshooting, close all the
programs and restart the computer as you normally would.
4. 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.
a.. For Norton AntiVirus consumer products: Read the document, "How to
configure Norton AntiVirus to scan all files."
b.. For Symantec AntiVirus Enterprise products: Read the document, "How
to verify that a Symantec Corporate antivirus product is set to scan all
files."
2.. Run a full system scan.
3.. If any files are detected as infected with W32.Spybot.Worm.
4.. Write down the filenames, and then click Delete.
5. Deleting the value from the registry
CAUTION: Symantec strongly recommends that you back up the registry before
making 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
then click OK. (The Registry Editor opens.)
3.. Navigate to the key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
4.. In the right pane, delete any values that refer to the filename that
was detected as infected with W32.Spybot.Worm.
5.. Navigate to the key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
6.. In the right pane, delete any values that reference the filename in
step d.
7.. Exit the Registry Editor.
6. Delete the zero-byte files from the Startup Folder
Follow the instructions for your operating system:
NOTE: There may be legitimate files on your system that start with "tftp."
Make sure to only delete the zero-byte files from the Startup folder.
Windows 95/98/Me/NT/2000
1.. Click Start, point to Find or Search, and then click Files or Folders.
2.. Make sure that "Look in" is set to (C
and that "Include subfolders"
is checked.
3.. In the "Named" or "Search for..." box, type, or copy and paste, the
file name, tftp*.*
4.. Click Find Now or Search Now.
5.. Delete the files that are zero-bytes and contained within any folder
that ends with "Startup."
Windows XP
1.. Click Start, and then click Search.
2.. Click All files and folders.
3.. In the "All or part of the file name" box, type, or copy and paste,
the file names tftp*.*
4.. Verify that "Look in" is set to "Local Hard Drives" or to (C
.
5.. Click "More advanced options."
6.. Check "Search system folders."
7.. Check "Search subfolders."
8.. Click Search.
9.. Delete the files that are zero-bytes and contained within any folder
that ends with "Startup."
