Lately, you may have noticed a large increase in the amount of spam hitting your inbox. In the past six weeks, the online world has seen a sharp rise in the rate of spam. Many corporate systems administrators have watched spam increase by double across their network.
Equally disturbing are the newer types of messages being sent, with text hidden within images to fool spam filters, not to mention the ways spammers are sending out the bulk messages in such quantity that they overload the spam filters entirely. While spammers employ ever-changing tactics, the one goal they all share in common is to flood your inbox with their messages.
As a hosting provider, we are charged with providing a stable, secure hosting environment for each of our clients. To that end, one of our biggest challenges is to block and prevent spam attacks that hit our network. In recent weeks, we've kept busy analyzing spam attacks that are occuring with increasing regularity. We're not the only ones, either. A recent article on
NetworkWorld.com has chronicled how administrators around the globe are constantly fending off newer and stronger spam assaults.
More Online Users = More Spam Zombies
In part, the ever-growing online user base is to blame. As more and more home users connect to the Internet through high-speed service providers, many of these users are unprotected against viruses and other programs designed to infiltrate their computers. The programs infect the computers, turning them into 'zombie' systems that are then instructed to send out spams by the thousands.
Although service providers can block an offending computer, the sheer volume of zombied systems has risen dramatically. Hundreds of thousands of zombie computers, spanning thousands of ISPs, are all working as an orchestrated effort to simultaneously spam millions of web sites across the planet. There seem to simply be too many infected systems for all of the ISPs and hosting companies to effectively block -- that is, without also blocking out millions of valid customers whose computers are protected.
Indeed, looking over thousands of inbound spams, many of them originate from distinct IP addresss (the physical location of the sending computer on the Internet). It's not as if 1,000 spams were sent from a single computer, which we could easily block. Instead, it's as if 500 computers were used to send those 1,000 spams. This makes manually blocking the offending systems a very arduous task.
Spam Filtering To The Rescue!
However, we and other hosting providers have access to a wide range of spam filtering services. Some are better than others. These services are designed to automatically detect, analyze, and filter spams, and further, block senders of those messages. One of the more popular products is known as SpamAssassin. This spam filtering software is incredibly powerful, as it not only analyzes some 100 different aspects of an email to determine if it is spam, but also subscribes a mailserver to a constantly-updated blocklist of known offenders.
This product works very well in most circumstances. Where it begins to fall short, however, is when a network is being flooded with thousands upon thousands of inbound spams. SpamAssassin will filter as much as it can -- but should there be overflow spam that it simply cannot get to, it will actually allow that overflow to be passed on to the intended recipients. This means the filtering will work up to an extent, but then users can expect to start getting hit with spam again.
To counter this, multiple instances (copies) of SpamAssassin can be set to run concurrently on a server. So if one isn't enough, you can add two, three, four... as many copies of SpamAssassin are needed, in order to combat the level of spam. The downside of this is that for each instance of the filtering software running on a server, more and more memory, CPU capacity, and sheer processing power are sucked up by the filtering service. So while spam levels drop, at the same time, the speed of the server may drop as well. As you can see, spam filtering can be a careful balancing act, between blocking the spam, and optimizing the performance of all our servers. Both can adversely affect our customers.
In the next few years, look for a new kind of weapon to emerge in the fight against spam. Soon, service providers across the globe will begin using authentication keys to validate that a message came from their network, but an authenticated user. When your ISP receives an authenticated email intended for you, the ISP will be able to immediately determine that the message sent was truly intended for you, sent from the address it claims it was, and so is most likely valid mail. If it is a spam, then the sender's ISP will be able to immediately notify (and potentially block) that user from ever sending spam again.
Authentication keys should dramatically help in the reduction of spam. Currently in testing by several large email providers, we at Canvas Dreams plan on rolling out this service across our network just as soon as it is viable for commercial use. This system will let recipients of our clients' emails know that the message sent were valid, and not spam. Spams, on the other hand, designed to look as if they came from one of our clients, will not be authenticated, and be immediately deleted by other ISPs, without any harm done to (e.g. blacklisting) one of our users. This new service will essentially stop spam the moment it is sent out by a spammer or zombie, and protect the rest of online users who have legitimate business.
Ways You Can Combat Spam
As an online user, you have many ways to protect your computer and email inbox from falling victim to spam attacks. Here are a few quick suggestions you can employ that can have a profound impact on the spam that clogs up your online experience.
1. Do not reply to spams with an unsubscribe request. This is the most surefire way for a spammer to confirm that your email address is active, and worse, being read by a living person. While many spammers claim they'll unsubscribe you, what they don't say is that they'll turn right around and sell your confirmed email address to ten more spammers. So, avoid the temptation to tell the spammer off, and do NOT reply to any messages, for any reason.
2. Avoid publishing your email address anywhere online. Automated robots employed by spammers are designed to actively browse the Internet and dig up published email addresses. The less your email address appears online (especially, on your web site), the less likely you are to end up on spam lists.
3. Avoid posting to newsgroups from your primary email address. Newsgroups are wonderfully rich, free online discussion lists that can give you an audience, and a community, in which to share your ideas. However, every message you post has an email address assigned to it. Most often, it's the address you used when you subscribed to the list. If at all possible, use a fake email address, or at least a secondary address from a third-party free email service like Hotmail, YahooMail, or GMail, so you don't end up receiving a lot of spam at your primary address.
4. Report spams to spam-fighting services like spamcop.net. Many spam-fighters exist that let you report spams, and then leave it up the the spam-fighter to investigate, and potentially place the network of the offender onto a blacklist. Many service providers subscribe to these blacklists, and actively block any email sent to their users, from a network on the blacklist. This usually results in the blocked network immediately removing the offending party, so the network can be de-listed, and begin sending out valid email again. Online spam-fighters, such as spamcop.net, enable you to post your emails through their systems, to be analyzed as spam. They will tell you where to report the spam, and if other users continue to report the offending network, that network will be blocked. It's a simple, easy, and very effective means for you to fight spam.
5. Choose a Web host that offers spam-blocking services. Hopefully, this is a no-brainer. Choose a host that understands the issues, cares about the issues, cares about your right to have a secure, spam-free inbox, and most importantly, will act on that knowledge and put in place blocking services like SpamAssassin.
6. Utilize spam-blocking software on your PC. If you still receive a hefty amount of junk, consider purchasing spam filtering for use directly on your personal computer. Many PC-based packages offer subscriptions to blacklists as well, so you can have added assurance that the extra filtering will actually do its job.
7. Keep your personal computer's anti-virus software current. To prevent your systems from being invaded and turned into a spam zombie, use industry-standard anti-virus software such as from Norton or Symantec. Daily-updated virus definitions help keep your computer constantly on the lookout for new kinds of attacks.
The Big Picture
Spam filtering is a constant battle of protecting our customers and ensuring the integrity of our network. It is a complex, involved process that sometimes seems to work better than others. While spammers constantly adapt to slip their messages past insecure networks and spam filters, hosting providers are likewise adapting back, and fighting the spammers with ever-increasing arsenals of tools.
Until the time Canvas Dreams begins using email authentication software, we'll continue our fight against spam in the tried-and-true way we have been doing it: analzying our networks; monitoring spammers and their tactics; keeping our anti-spam measures current; and above all, listening to our customers to help us determine how best we can improve their online experience.
Best Regards,
Canvas Dreams Staff
