Because search is one of the most popular functions on the web, spammers have long leered at it with lustful eyes. One method they use to corrupt the process is Search Engine Optimization (SEO) poisoning. It works like this.
A spammer will create a web page pegged to a popular search term. It can be a news event–the Haitian earthquake, for instance–or a celebrity–such as Justin Bieber. Finding the hottest terms isn’t that hard. Google does it for them with its “Hot Trends” feature. Then they cross-link the page with hundreds of other spam pages floating in the ether. And there are plenty of pages to choose from. One recent analysis of 27 million websites found that 31.3 percent of them were considered risky for malware distribution and attack code.
Moreover, the pages aren’t dumb. They’re designed to filter incoming traffic. If a visitor isn’t being redirected to the site by a search engine, they’ll be sent to a non-malicious web page. Visitors from search engines are shipped to a site where they can be spammed or infected with malware. Typically, they’re sent to a site offering free downloads of bogus antivirus software. The tactic makes the sites hard to detect by spamfighters.
The problem of SEO poisoning has been growing at an alarming rate. At any one time, more than 100 of the top 300 search terms contained at least 10 percent malicious links, according to one security firm. That means that an Internet searcher has a one in three chance of being sent to a malicious websiste from a search page. That same security firm estimates that 15 of the first 70 hits in a search will contain malicious links.
What’s more, the problem keeps getting worse. Researchers conducting Google searches since June recently reported that 22.4 percent of the searches contained links to bad websites in the first 100 search results. That’s a nine percent increase over last year when, during the same period, the contamination rate was 13.7 percent.
That increase now makes it, ironically, more likely to get infected by malware by following up search results than visiting pornography sites, according to the report.
Concerns over poisoned search results appear to have had a positive impact on a new search engine called Blekko. The engine attempts to weed out spam results in searches by using slashtags. The tags are used to refine searches and return more relevant results. So if you type “spam” into the search field at the site, a list will pop up. It includes search terms such as spam /techblogs, spam /tech, spam /it and spamalot. The search can be further refined by changing the root term to “spam junk.” That produces a list of searches that include spam junk mail and spam junk email.
The engine appears to have caught the imagination of many web ferrets. After running for only a week, Blekko was routinely racking up a million searches a day. That’s a far cry from search leader Google’s 300 million searches a day, but it’s still a good start.
Although Blekko is a new search engine, it harkens back to the times when humans had more to say than they do now about what results search terms return. During those times, the links on which pages were ranked in search results were created by humans, not robots.
Blekko hopes to bring to search what Wikipedia brought to knowledge. Using a combination of editorial staff and users of the search engine itself, it associates a list of trusted sites to a given slashtag. That screens out results from lots of junk sites–content farms, for instance, and made-for-adsense landing pages–that can poison those results with spam. On the other hand, the breadth of the search is being severely limited. For most Net hunters, that shouldn’t be a problem, according to the brain behind Blekko, Rick Skrenta.
“If you make a list of the 100 top health sites, they can answer every health query you have,” he told Christopher Mims writing for MIT’s Technology Review. “These sites are written by doctors, they have medical librarians on staff–they speak to every medical topic. You don’t really want to search outside of that set.”
Whether Blekko can attract enough searchers who are fed up with spam infested results provided by the leading search engines remains to be seen. One thing is certain, though, if it starts to garner a significant number of eyeballs, spammers will find a way to poison its results, too.