Blaster Worm Advisory
Concord,NH, AUGUST 12, 2005
Many computer users are experiencing the effects of a new virus going
around this week. The cure for the virus is fairly
straight-forward, although you must be diligent about reading the
We at Mission Control
working diligently to help customers affected by this problem.
Fortunately most of our customers are already immune because of the
way their networks were set up. If you have this problem and
need our assistance please call the office at (603) 581-2604. We
will assist you as soon as possible.
The current virus
(called the Blaster Worm) only affects computers running
Windows XP, Windows 2000, or Windows NT 4.0. Computers running any
other version of Windows (98, 95, ME, Vista) are not affected by this
Who is affected?
This worm can affect anyone with a
connection to the Internet but without a "firewall" protecting your
computer. The people most often affected by this problem
are home users who use a dial-up modem connection to the Internet,
although users on a cable modem or DSL modem could be affected also if
they do not have a firewall installed.
A firewall is also known as a
broadband router. If you have DSL or cable modem service you
should have one of these. Some common routers are made by
Linksys, Netgear, and D-Link. You can buy them off the shelf at
Best Buy, Circuit City, and CompUSA. If you have one of
these routers you are not directly affected by this problem, although
you should still update your system. If you don't, we strongly
recommend buying one.
Windows XP has a firewall built in to
the software, but you have to turn it on. If you turn on this
firewall you will be protected against this worm. See the
instructions below for details.
What to do about it?
If you are using Windows NT 4.0, Windows 2000, Windows XP, or Windows
Server 2003, you should follow the steps in this sequence to help
protect your system and to recover if your system has been infected.
Make sure you have a firewall installed and
activated to help protect your computer against infection, before
you take other steps. If your computer has been infected, activating
firewall software will help limit the effects of the worm on your
If you have
Windows XP or Windows Server 2003,
follow these instructions to enable the Internet Connection
If you have
Windows NT 4.0 or Windows 2000, you will need to install a
third-party firewall. Most firewall software for home users is
available in free or trial versions. Check the following resources
for more information on personal firewalls:
These products also work with Windows XP.
Alternatively, if you use Windows 2000, you can take steps to
block the affected ports so that your computer can be patched.
Here are some modified instructions from the TechNet article
Configure TCP/IP Filtering in Windows 2000.
Control Panel, double-click Network and Dial-up
Right-click the interface you use to access the Internet, and
then click Properties.
Components checked are used by this connection box, click
Internet Protocol (TCP/IP), and then click Properties.
Internet Protocol (TCP/IP) Properties dialog box, click
the Options tab.
TCP/IP filtering, and then click Properties.
the Enable TCP/IP Filtering (All adapters) check box.
are three columns with the following labels:
In each column, you must select the
Permit Only option.
Download and install the security update
addressed in Security Bulletin by clicking here:
Select the version of Windows
that you are using (scroll down to the Resolution heading). Select
your operating system. Click on the link and do one of the following:
Make sure you install and use antivirus
If you think your computer has been infected,
use the worm removal tool available at your antivirus vendor's Web
site. For additional details on this worm from antivirus software
vendors participating in the Microsoft Virus Information Alliance
(VIA) please visit the following links:
Microsoft's Virus Information Alliance.