Here is an interesting article from one of my favorite newsletters that I thought would be appropriate to share with all of you:
Batten the Hatches
The spate of recent worms makes it clear that way too many people aren't
keeping their PCs secure.
For example, the "Blaster" worm (the first of the recent bunch) spread
itself by email or by direct infection via unguarded network ports. But
any good AV tool, and some high-quality desktop firewalls like
ZoneAlarm, defang hostile inbound mail attachments: This would have
closed off email as an infection vector for this kind of worm attack.
Any decent firewall--- even the simplest--- can block the port probes
that worms like this use to seek new local victims, totally closing off
that infection vector. And the better desktop firewalls also alert you
to suspicious *outbound* activity from your PC, so even if your PC were
somehow infected, you could still see what was going on, and prevent
your machine from infecting others.
And here's the part that makes me just scratch my head in wonder. The
worm was designed to take advantage of a Windows security hole for which
a patch had been released (via a "Critical Update") a month *before* the
worm surfaced! This is a worm that should have gone nowhere.
But clearly, huge numbers of systems were running unpatched,
unprotected, and wide open; millions of PCs were thus needlessly
compromised. Of course, the usual "it's Microsoft's fault!" cry went up.
And while some problems *are* Microsoft's fault, I don't see how we can
pin this one on them. People whose PCs were infected in this outbreak
had ignored a "Critical Update" AND/OR were running unprotected by
desktop firewalls AND/OR were running without up-to-date antivirus
tools. Those are voluntary choices, and (as many found out) ones with
bad consequences.
Many readers of this newsletter are running very well-protected, so I
don't want to bore you by "preaching to the choir." But if you have
coworkers or friends who are leaving themselves open (especially if they
were among the millions and millions who got bit by one or more of the
worms)--- or if you're not well protected yourself--- this may help:
First, stay patched. I know some users worry about applying Critical
Updates, because they sometimes do cause new problems. Up to a point,
that kind of caution is a good thing.
Assuming you have a good antivirus tool and a good desktop firewall
running to protect you from the most-frequent infection vectors, then it
can make sense to wait a few days after a Critical Update appears to see
if others have trouble with it. But it rarely makes sense to wait weeks
or months before applying a Critical Update, and I can think of no
reason just to ignore them: They're called "critical" for a reason.
And please note that you can apply the Critical Updates as soon as they
appear, if you have a good backup process. Then, if something doesn't
work out, it's no big deal because you can undo the change in a matter
of minutes.
For that matter, you usually can apply Critical Update right away
anyway: Although some Critical Updates have caused trouble, most of them
work exactly as they should.
These links may further help:
How to easily set up a multilayered defense for your PC using free or
low-cost software:
http://www.informationweek.com/840/langa.htm
Safe ways to test your PC's defenses to make sure they're up to snuff:
http://www.informationweek.com/841/langa.htm
How to weigh the risks and benefits of applying security patches to your PC:
http://www.informationweek.com/story/showArticle.jhtml?articleID=9901256