How Spammers Slip ThroughMarch 3, 2006
You didn't expect spammers to give up without a fight, did you?
Now that you've successfully blocked most of those lewd come-ons, penny stock pitches, and Viagra ads, they seem to be creeping back into your users' inboxes. Right off the bat you'll notice that the subject lines are packed with obvious, if sometimes unintentionally funny misspellings.
As amazing as it is to see those forbidden four-letter words gain exotic new spellings, it doesn't compare to the tricks spammers play within the body of the email. Of course, since text-only spam is a notoriously ineffective vehicle for titillating the masses, most of those tricks are HTML-based.
Don't be fooled, however. Even with plain text you'll often be faced with a barrage of nonsense that seems to have spilled from those ridiculous subject lines. This is designed to normalize an otherwise alarming Bayesian score, letting spam work its way through by counteracting scandalous terms with unexceptional words.
But, surely, the e-mail's content would set off alarms and trigger a block?
It takes some tinkering and time for filtering software to become adept at deciphering the context of a spam message and start weeding out the gibberish. That's why spammers rush to get through this window of opportunity before it closes on them and are forced to adopt other methods.
But it goes deeper than that. Thanks to the miracle (or curse) of HTML email, spammers add elements -- graphics actually -- that alert them to the presence of a real, active email account when the spammer's servers are sent requests for those elements. As expected, more spam follows. Luckily many online email services, along with Outlook 2003, got wise to this tactic and now have automatic image downloads turned off by default.
Even so, you'll find that denying spammers their bounty takes vigilance and some proactive steps. And that's where this AO spotlight comes in.
Learn how to examine the anatomy of today's spam. With that knowledge, and some tweaks to your spam blockers, you'll be well on your way to enjoying a clean inbox again.
Note: Any opinions expressed below are solely those of the individual posters on the AntiOnline forums.
DerekK notices that spam is starting to make a comeback...
After taking a look at an example, Tiger Shark offers this explanation:
And jcjzbrfay makes a debut with this thoughtful analysis:
Learn more and join the discussion here.