Showing posts with label Firewall. Show all posts
Showing posts with label Firewall. Show all posts

Wednesday, August 16, 2006

Are You A Spam Zombie?

Over the past few years you've all become familiar with the terms spam, spam filter, whitelists, blacklists and a whole myriad of other terminology associated with the problem of spam. You now have to add a new and extremely worrying phrase to that list - spam zombie.

With the net closing in around them spammers are looking for new and more inventive ways to send out their junk email. Spam filters and challenge response systems are becoming progressively more intelligent and blocking more spam each day. What was a spammer to do? The spammers took the next step - infiltrating your PC and using it as a spamming tool.

When most of you think of the word zombie you're reminded of old B movies with groaning zombies chasing the terrified actress through a castle, swamp or whatever low cost setting the movie revolved around. Spam zombies are, however, far more real and far more dangerous.

A spam zombie is when your computer is taken over by a type of virus called a Trojan. Once this Trojan virus is on your computer it sets up an SMTP (Simple Mail Transfer Protocol) application which allows it to begin sending email directly from your PC to tens of thousands of victims. This all happens invisibly in the background and can be difficult to detect for even the experienced computer user.

How do these Trojans get onto your computer? As in most cases they come from porn, warez or similar sites. One of the first spam zombie trojans to appear became available via a link on sites promising viewers free access to a porno webcam. One click later and the Trojan is installed on your computer ready to send out spam. Phatbot and Proxy-Guzu are two of the more common Trojans used for the purpose of turning your computer into a spam zombie.

How can you check if your computer has become a spam zombie? Make absolutely certain that both your anti-virus and firewall software have current detection signatures and have been completely patched and updated. Working online without taking these necessary security precautions is simply asking for trouble.

Internet Service Providers are under huge pressure to quarantine the IP address of any computer which has been turned into a spam zombie. This is done on the basis that the ISP risks their entire IP range being blacklisted or banned by some spam filtering services or companies.

The very least you owe yourself is to run a full virus and spyware scan on your computer today. You might be unpleasantly surprised at what you'll find lurking there.

About the author:
Niall Roche
This article was provided courtesy of Spam-site.com which reviews spam blocking software and other anti spam utilties.
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Wednesday, August 02, 2006

Anti Spam at the Enterprise Level

Every one of us knows how spam impacts us. Every day we either get a ton of spam - or if we're fairly well protected by spam filters - only a few pieces.

Like a large number of people, I don't use any spam filters. Ah. You think I'm insane. But wait. My problem is that I get a lot of email from marketing types which I want to receive. And the spam filtering software is not very sensitive to my needs. Even white-listing doesn't always work. So, I prefer to get all that spam and just delete it.

Now this solution can work for me despite the time it takes to delete my daily overdose of spam. However, at the enterprise level, it's a whole different story. If you have a relatively large internal network with even a modest number of email users, you're looking at a major problem. And the more users you have, the worse the problem is.

Sure, you can put up software on the mail server. Works, kind of. But pretty soon you may find you need to upgrade the mail server. And that's after you already put it on a stand-alone machine.

Rather than continuing to buy ever more expensive software to run on a machine that keeps needing to be upgraded, you might want to think about a dedicated anti spam appliance.

To give you some idea of what's possible let's take a look at Barracuda Networks dedicated anti spam appliance. All you need to do is put this baby in front of your mail server. I say baby, advisedly because this one will learn by doing and by training provided by your users.

Dean Drako, CEO of Barracuda Networks said, "Bayesian filtering is still one of the most accurate defenses against spam. The new plug-ins allow users to directly train the Bayesian filter, making the Barracuda Spam Firewall even more accurate based on the users individual email preferences. Viruses and other threats can infect the network quickly if they are not stopped at the network edge. With Intent Analysis our customers have an advantage over these threats because the Barracuda Spam Firewall is able to block them real time. Consequently we have consistently been a first responder when some of the most malicious virus attacks have hit, saving our customers from potentially devastating damage to their networks."

This is one beautiful little machine. A Barracuda Spam Firewall can support from 1,000 to 30,000 active users. It can usually be installed in less than five minutes and receives automatic hourly updates for new forms of spam and viruses. It has a 10 layer defense system beyond the use of open source anti spam and anti virus solutions: denial of service and security protection, IP block list, rate control, virus check with archive decompression, proprietary virus check, user specified rules, spam fingerprint check, Intent Analysis, spam rule-based scoring, and Bayesian analysis. Plus it also does both inbound and outbound email filtering with the inclusion of sophisticated outbound email filtering techniques (just in case you've got a spam zombie on board or somebody's got an infected PC).

However, it isn't exactly cheap. Still, when you consider the time, bandwidth, user frustration and potential hardware upgrade costs, the price may look a lot more reasonable. You can check it out at http://www.barracudanetworks.com/

If you are in the market for an anti-spam appliance, the Barracuda Spam Firewall isn't your only choice. The impact of spam on internet businesses - even those who primarily use it for just email - is so great that a simple search for "anti spam appliance" will find you a number of alternatives to examine. Even McAfee is getting into the anti spam hardware game.

I'm hoping that it won't be too long before I can pick up a Bayesian multi-level anti spam, anti virus firewall appliance for my home PC that keeps me safe and cuts my need to delete without deep-sixing the email I want or costing me more than I can afford. I suspect it's on the way.

About the author:
Richard Keir writes in a variety of areas involving eBusiness and the internet. For more on spam visit http://anti-spam.werkz.org and for general eCommerce go to http://building-ecommerce-websites.com
Copyright 2005 Richard Keir
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