This guide is created specifically for a type of hack that adds keyword-heavy gibberish pages to your site which we'll refer to as the cloaked keywords and links hack. It's designed for users of popular Content Management Systems (CMSs), but you'll find this guide useful even if you don't use a CMS.
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Identifying this type of hack
The cloaked keywords and link hack automatically creates many pages with nonsensical text, links, and images. These pages sometimes contain basic template elements from the original site, so at first glance, the pages might look like normal parts of your site until you read the content.
The hacked pages are created to manipulate Google's ranking factors. Hackers will often attempt to monetize this by selling the links on the hacked pages to different 3rd parties. Often the hacked pages will also redirect visitors to an unrelated page, like a porn site where hackers can earn money.
Start by checking the
tool in Search Console to see if Google has discovered any of these hacked
pages on your site. Sometimes you can also uncover pages like this by
opening a Google Search window and typing in
site:_your site url_, with
the root level URL of your site. This will show you the pages that Google
has indexed for your site, including the hacked pages. Flip through a
couple of pages of search results to see if you spot any unusual URLs.
If you don't see any hacked content in Google Search, use the same search
terms with a different search engine. An example of what that would
look like is below.
Typically, when you click a link to a hacked page you will either be redirected to another site, or you will see a page full of gibberish content. However, you might also see a message suggesting that the page does not exist (for example, a 404 error). Don't be fooled! Hackers will try to trick you into thinking the page is gone or fixed when it's still hacked. They do this by cloaking content. Check for cloaking by entering your site's URLs in the Inspect URL tool tool. The Fetch as Google tool allows you to see the underlying hidden content.
If you see these issues, your site has most likely been affected by this type of hack.
Fixing the hack
Before you start, make an offline copy of any files before you remove them, in case you need to restore them later. Better yet, back up your entire site before you start the cleanup process. You can do this by saving all the files that are on your server to a location off your server or searching for the best backup options for your particular Content Management System (CMS). If you're using a CMS, you should back up the database as well.
.htaccess file (3 steps)
The cloaked keywords and link hack uses your
.htaccess file to automatically
create cloaked pages on your site. Familiarizing yourself with
on the official Apache site can help you understand better how the hack is
affecting your site, but it isn't required.
.htaccess file on your site. If you're not sure where to find it
and you're using a CMS like WordPress, Joomla, or Drupal, search for
".htaccess file location" in a search engine along with the name of your CMS.
Depending on your site, you might see multiple
Make a list of all of
.htaccess file locations.
.htaccess file to view the contents in the file. In the file, you
should be able to identify one line of code that looks something like the
RewriteRule (.*cj2fa.*|^tobeornottobe$) /injected_file.php?q=$1 [L]
The variables on this line can change. Both
be any mix of letters or words. What's important is to identify the
that's referenced in this line.
Write down the
.php file mentioned in the
.htaccess file. In the example,
.php file is named
injected_file.php, but in reality the name of
.php file won't be as obvious. It's usually a random set of innocuous
potatolake.php, and so on. There's a high
chance this is a malicious
.php file we'll need to track down and
.htaccess files with a clean or default version of the
.htaccess file. You can usually find a default version of a
file by searching for "default
.htaccess file" and the name of your CMS.
For sites with multiple
.htaccess files, find a clean version of each one
and perform the replacement.
If no default
.htaccess exists and you've never configured an
file on your site, the
.htaccess file you find on your site is probably
malicious. Save a copy of the
.htaccess file(s) offline just in case and
.htaccess file from your site.
Finding and removing other malicious files (5 steps)
Identifying malicious files can be tricky and can take several hours. Take your time when checking your files. If you haven't yet, this is a good time to back up the files on your site. Do a Google search for "back up site" and the name of your CMS to find instructions on how to back up your site.
If you use a CMS, reinstall all the core (default) files that come in the default distribution of your CMS, as well as anything you may have added (such as themes, modules, plugins). This helps ensure that these files are clear of hacked content. You can do a Google search for "reinstall" and your CMS name to find instructions on the reinstallation process. If you have any plugins, modules, extensions, or themes, make sure to reinstall those as well.
Start by looking for the
.php file that you identified in the
file earlier. Depending on how you're accessing the files on your server,
you should have some type of search functionality. Search for the
malicious file name. If you find it, first make a backup copy and
store it in another location just in case you need to restore it,
then delete it from your site.
Look for any other malicious or compromised files left. You might have already removed all malicious files in the previous two steps, but it's best to work through these next few steps in case there are more files on your site that have been compromised.
Don't get overwhelmed by thinking that you need to open and look through every PHP file. Start by creating a list of suspicious PHP files that you want to investigate. Here are a few ways to determine which PHP files are suspicious:
- If you've already reloaded your CMS files, look only at files that are not part of your default CMS files or folders. This should rule out a large number of PHP files and leave you with a handful of files to look at.
- Sort the files on your site by the date they were last modified. Look for files that were modified within a few months of the time that you first discovered your site was hacked.
- Sort the files on your site by size. Look for any unusually large files.
Once you have a list of suspicious PHP files, check to see if they are malicious. If you're unfamiliar with PHP, this process might be more time consuming, so consider brushing up on some PHP documentation. If you're completely new to coding, we recommend getting help. In the meantime, there are some basic patterns that you can look for to identify malicious files.
If you use a CMS, and are not in the habit of editing those files directly, compare the files on your server to a list of the default files packaged with the CMS and any plugins and themes. Look for files that do not belong, as well as files whose sizes seem larger than their defaults.
First, scan through the suspicious files you've already identified to
look for large blocks of text with a combination of seemingly jumbled
letters and numbers. The large block of text is usually preceded by a
combination of PHP functions like
gzinflate. Here is an example of what the block of code might
look like. Sometimes all this code will be stuffed into one long line
of text, making it look smaller than it actually is.
// Hackers try to confuse webmasters by encoding malicious code into // blocks of texts. Be wary of unfamiliar code blocks like this. base64_decode(strrev("hMXZpRXaslmYhJXZuxWd2BSZ0l2cgknbhByZul2czVmckRWYgknYgM3ajFGd0FGIlJXd0Vn ZgknbhBSbvJnZgUGdpNHIyV3b5BSZyV3YlNHIvRHI0V2Zy9mZgQ3Ju9GRg4SZ0l2cgIXdvlHI4lmZg4WYjBSdvlHIsU2c hVmcnBydvJGblBiZvBCdpJGIhBCZuFGIl1Wa0BCa0l2dgQXdCBiLkJXYoBSZiBibhNGIlR2bjBycphGdgcmbpRXYjNXdmJ2b lRGI5xWZ0Fmb1RncvZmbVBiLn5WauVGcwFGagM3J0FGa3BCZuFGdzJXZk5Wdg8GdgU3b5BicvZGI0xWdjlmZmlGZgQXagU2ah 1GIvRHIzlGa0BSZrlGbgUGZvNGIlRWaoByb0BSZrlGbgMnclt2YhhEIuUGZvNGIlxmYhRWYlJnb1BychByZulGZhJXZ1F3ch 1GIlR2bjBCZlRXYjNXdmJ2bgMXdvl2YpxWYtBiZvBSZjVWawBSYgMXagMXaoRFIskGS"));
Sometimes the code isn't jumbled and just looks like normal script. If you're not certain whether or not the code is bad, stop by our Webmaster Help Forums where a group of experienced webmasters can help you look over the files.
Now that you know which files are suspicious, create a backup or a local copy by saving them onto your computer just in case it wasn't malicious, and delete the suspicious files.
Check to see if your site is clean
Once you're done getting rid of hacked files, check to see if your hard work paid off. Remember those gibberish pages you identified earlier? Use the Fetch as Google tool on them again to see if they still exist. If they respond as "Not Found" in Fetch as Google, chances are you're in pretty good shape and you can move on to fixing the vulnerabilities on your site.
How do I prevent getting hacked again?
Fixing vulnerabilities on your site is an essential final step for fixing your site. A recent study done found that 20% of hacked sites get hacked again within 1 day. Knowing exactly how your site was hacked is helpful. Read our top ways websites get hacked by spammers guide to start your investigation. However, if you're unable to find out how your site was hacked, below is a checklist of things you can do reduce vulnerabilities on your site.
- Regularly scan your computer: Use any popular virus scanner to check for viruses or vulnerabilities.
- Regularly change your passwords: Regularly changing the passwords to all your website accounts like your hosting provider, FTP, and CMS can prevent unauthorized access to your site. It's important to create a strong, unique password for each account.
- Use Two-Factor Authentication (2FA): Consider enabling 2FA on any service that requires you to log in. 2FA makes it harder for hackers to log in even if they successfully steal your password.
- Update your CMS, plugins, extensions, and modules regularly: Hopefully you've already done this step. Many sites get hacked because of the outdated software running on a site. Some CMSs support auto-updating.
- Consider subscribing to a security service to monitor your site: There's a lot of great services out there that can help you monitor your site for a small fee. Consider registering with them to keep your site safe.
If you're still having trouble fixing your site, there are a few more resources that might help you.
These tools scan your site and may be able to find problematic content. Other than VirusTotal, Google doesn't run or support them.
Virus Total, Aw-snap.info, Sucuri Site Check, Quttera: These are just some tools that may be able to scan your site for problematic content. Keep in mind that these scanners can't guarantee that they will identify every type of problematic content.
Here are additional resources from Google that can help you: