14 DAY TRIAL // The old black hat SEO technique of using white text on white backgrounds to hide page content is making a comeback, and crooks are using it to avoid spam filtering and detection engines.
Back in the early days of Web development when SEO was just like the Wild West, some developers resorted to inserting so-called SEO (or keyword) bombs in their text by placing a lot of keywords in the page's content.
The text was set to appear with the same color as the page's background, remaining invisible to the human eye, but visible to search engines.
The trick was used to increase a page's ranking in Google search results, but the company quickly resolved the issue and nowadays, any developer that's crazy enough to use SEO bombs might just find his site blacklisted on Google altogether.
Black hat SEO technique resurrected by spammers
According to Sucuri's Peter Gramantik, this technique has resurfaced in a modified version, not to improve SEO rankings, but to help spam email pass through spam filters, and Web pages from being detected as spam.
The trick relies on inserting spaces between words and then inserting other characters as the same color as the background. For example, the famous Viagra spam term would appear as this on a Web page (notice the big gaps between letters): "V i a g r a".
Users would still be able to read it, but in the page's source code, the text would actually be "Vx ni 3a g5 rt sa". Search engines crawlers, spam filters, and spam detection engines would see this word puzzle and ignore it, not being either spam or a bunch of SEO keywords. Nevertheless, the user would see it as spam, which it actually is.
Crooks prove once again they can sometimes combine two different shady techniques from two different domains, and achieve their goals. The crooks' target was for the user to see the spam, which they did, even at the cost of losing some of the page's SEO juice.
