Friday, October 16, 2009


New technique for comment spam

Screen image of blog commentsThe other day, I left a comment on this post at the 360 blog — a math-related blog run by some math professors in Rochester, NY. I went back the next day to see if there were responses to my comment, and I found that a few hours after I posted it, someone had re-posted the same comment, adding the line, “Sorry... forgot to say great post - can’t wait to read your next one!” Click the screen-shot on the right to enlarge it, and you’ll see what it looked like.

Now, I didn’t post that second one, and there are a few clues to that:

  1. I wouldn’t re-post the whole comment, just to add that line.
  2. I wouldn’t say the added line, in any case: it’s too trite.
  3. In a few ways, the added line isn’t up to my standards of punctuation.

    [You might not know any of that, but the last two are more obvious.]

  4. My photo isn’t there on the second comment.
  5. You can’t do it in the screen-image, but if you had put the mouse over my name in the two comments, you’d see that the first one correctly links to these pages, while the second one had a link to somewhere else.

And that link to somewhere else was, of course, the point of the second comment. Someone — undoubtedly some automated process — plucked the most recent comment off their blog entry, appended the extra line, and re-posted it with the same name, but with a different link. It’s link spam. But it’s link spam using a technique I haven’t seen before. It’s actually quite a clever idea.

My comment was acceptable to the target blog, as seen by its presence there. So by using my name and repeating the content of my comment, the spam comment was expected to pass muster. And it did — in fact, it bypassed the blog’s moderation queue, because I’m a known commenter. They added an innocuous line that was unlikely to override the other good points and trigger suspicion, but which provided a semi-plausible excuse for the re-posting.

Of course, they weren’t actually logged in as me, so they didn’t get my profile photo (and they couldn’t easily fake that, because the system would require them to register an account in order to have a photo there).

What they’re doing is one of the sleazy aspects of the business that’s come to be called “Search Engine Optimization” (SEO). The legitimate part of the business involves giving people advice on designing their web site to maximize the likelihood that the site will show up as one of the top “hits” when someone searches for their business’s name, or for related search terms. The sleazy part involves using techniques like link spam to artificially push their site up in the search results. Because Google uses the number of links to a web site from other sites as a factor in gauging the site’s popularity, and, therefore, likely relevance to a search, it’s in the SEO folks’ interest to pump up the number of links to their clients’ web sites.

Every time they manage to get a link to a client’s site into a comment on someone’s blog, they get one more tick mark from Google for it. They’re one step closer to pushing the client’s site higher in the search results.

And I’m having none of it. Just as email spammers give a bad name to companies that use email marketing appropriately and responsibly, these link-spammers give a bad name to responsible SEO consultants who do their work by helping their customers design good web sites.


Thomas J. Brown said...

So how does the story end? Did you contact the 360 blog and have them remove the comment?

This is a pretty sneaky tactic, and one that I haven't seen before either. I'll have to keep an eye out for this sort of thing from now on.

Sorry... forgot to say great post - can't wait to read your next one! Just kidding. -)

Barry Leiba said...

Yes... if you click through to the post, from the link I provided, you can see the last couple of comments. I asked for the bogus comment to be removed, and "batman" removed it... and said that he hadn't seen that technique before either.

Xi_Heather said...


I'm late responding to this, but I do have one clarification -- Wordpress was smarter than me in this case. It's true that known commenters are automatically approved on our site, but this particular comment didn't actually piggyback on that status. I can't remember if it was in the Spam folder, though I think it might have been -- I do know that I had to approve it, and I paused over it since it seemed odd for you to repost the comment just to add a line, but I just shrugged and approved it without noticing that the website didn't match yours.

It's still clever little Bot, but in theory I could have been cleverer.