Computer spam sees 'unprecedented' decline

(MoneyWatch) -- It's been such a gradual change that you might not have noticed, but the unthinkable has happened: Our collective spam problem is actually getting better. 

A recent report by cybersecurity company Kaspersky says that the amount of unsolicited online junk mail people get has reached a five-year low.

"This continual and considerable decrease in spam volumes is unprecedented," according to Kaspersky. "Moreover, the average percentage of spam in 2012 was substantially lower than in 2010 (82.2 percent) and 2011 (80.3 percent), when botnet command centers and pharmaceutical affiliate programs were actively shut down. In 2012, the percentage of unsolicited mail was as low as it's been over the previous five years."

As I recently explained in a blog post for website eHow, there are a few reasons why the spam trend has reversed. One obvious reason is that spam filtering has both gotten better and has become ubiquitous. There's less incentive to send spam if virtually every mail app and web service has effective filtering.

Moreover, some spammers have moved on to other methods, such as inexpensive banner ads, contextual advertising and social media. Travel and tourism spam has virtually disappeared, replaced by electronic coupon offers instead.

But just because spam is decreasing doesn't mean we should drop our guard. There are still steps you can -- and should -- take to protect yourself from unsolicited email:

Make sure your spam filter is turned on. Hopefully it's already on by default, but some mail programs and webmail services require you to enable spam filtering manually. It's not doing anyone any good if it's turned off.

Deal with your bacon. "Bacon" -- mail that might look like spam, but is really newsletters or other communication from businesses you have an established relationship with -- can be just as annoying as real spam if you're not interested in it. Stop receiving them by using the unsubscribe link at the bottom of those emails.

Never reply or respond to real spam. You wouldn't stick your arm in an alligator's open mouth, and you shouldn't encourage spam by doing the one thing that makes it grow: acknowledging its existence. If it's real spam rather than bacon, don't try to unsubscribe. And obviously never follow a link or buy something through one of these messages.

Run antivirus software. Your last line of defense from malware embedded in malicious spam and phishing attempts is whatever security software you have installed.