Tracking Down Rogue Spam Links

[hammia]

In Feb, 2015 www.mommyupgrade.com site received the following notification in GWT:

http://www.mommyupgrade.com/: Suspected hackingFeb 4, 2015
Google has detected that some of your pages may contain hidden text or cloaking, techniques that are outside our Webmaster Guidelines.
Specifically, we detected that your site may have been modified by a third party. Typically, the offending party gains access to an insecure directory that has open permissions. Many times, they will upload files or modify existing ones, which then show up as spam in our index.
Sample URLs:At that time,  the site was checked by the host and site owner and any suspicious links removed. We thought the problem was resolved until a MOZ crawl on March 22 which highlighted a number of hack links again.

This is the link format: http://www.mommyupgrade.com/?p=online-slots

All are related to gambling, casinos and slots.

To find the links, we downloaded the MOZ crawl report and found that all the links were referred from this page: http://www.mommyupgrade.com/how-to-make-rainbow-lollipop-cookies/

Searching that post shows no sign of links to the rogue pages.

I would really appreciate some advice on how to find the source of these links and delete them from this site once and for all. Also, please explain how it is possible for a post or page to refer to another page without that link showing up in the code? (Is this some black hat technique that I need to know about in order to protect my sites?)

Also... at the moment Google Webmaster Tools are not reporting any security issues for this site.

Any help appreciated.

[RyanPurkey]

You're welcome. I'm always amazed at the diversity of people that read and comment here. A lot of talented eyes are considering the questions for sure. Cheers!

[hammia]

@Ryan, that link is very useful and once we have the site clean we can use it regularly to check that no new issues presnt themselves.

@Richard, thank you for this information. It helps a lot.

Great community support. I wish I had asked this question days ago.Thank you MOZ.

[TheeDigital]

There are some base 64 encoded URLs on the page. They show in the source code like below. That would be my guess as to what is creating the links, which are obfuscated for users. These types of attacks are usually called in your functions.php file or within a hacked plugin, or could actually be inserted into the css as well.

background:url(data:image/png;base64,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)

[RyanPurkey]

You can also run a search like this to get at these pages: https://encrypted.google.com/search?hl=en&q=site%3Amommyupgrade.com inurl%3A%3F%3Dp

The root cause is a hack of your Wordpress installation, most likely a plugin. Here's a good discussion around how this takes place: https://wordpress.org/support/topic/someone-has-hacked-the-site-and-inserted-a-link

Recently a vulnerability was found in the Yoast plugin (see: http://thehackernews.com/2015/03/wordpress-seo-by-yoast-plugin.html ), so you'll certainly want to upgrade that and preferably set your updates to automatic.

Good luck!