Get Off Those Maliciously Loaded Scripts!
Download this free Anti-Malware Plugin for WordPress.

This is not a threat but rather a vulnerability called User Enumeration, which would permit anyone to discover your usernames using an unrestricted URL such as:
/?author=2

That is why it is one of the Firewall options that is enabled by default. If you wish for any un-authenticated visitor to be able to easily view this information about any user in your database by passing a common number like 1, 2, or 3 then you can simply disable the User Enumeration protection on my Anti-Malware plugin’s Firewall Options pages in your wp-admin.

Please feel free to let me know if you have any further questions about any of this.

Thanks for noticing, I hope to have some more really nice features coming soon

Check the permissions on your /tmp/ directory (or wherever your server stores session files, and also make sure that the partition is not full or write-protected.

Verify that mod_rewrite is installed and working and that Apache is able to run the code in the .htaccess files.

You can also look in your error_log files to see if it might tell you what the problem is.

You may need to ask you hosting provider for help with some of this if you don’t know where to look for these things. Maybe they can test your server’s ability to maintain a persistent session and just tell you what is causing this problem.

No, because reinstalling the plugin does not affect the registration. All you need to do is to click on the green checkbox in the upper-right corner of the Anti-Malware Settings page in the wp-admin of that site. Then change the email address on the registration form and re-submit the registration under your email.

The small bit of serialized code that my plugin originally put in that file does have an expiration date built into it but all that malicious code that was added to the top of that file has it’s own rules to live by and it needs to be removed before it has a chance to replicate itself into other files. As with all malicious injections, it is important to remove the malicious code as quickly as possible before it can spread to more of the files on your server. Quick containment and isolations is the key to getting clean and staying safe from further infection and future re-infection.

Since all the files in that _SESSION folder are temporary and not critical to the core functionality of your site you can delete the whole folder just to be safe. And session files that are needed to validate future login attampts will be recreated by my plugin anyway, and those will all be clean (at least until you get hit by another wave of infections).

Sorry for not posting a reply earlier, the notification of your post was sent to spam

Anyway, I hope that Steven’s response was helpful and you were able to fix this issue.

Also, I just checked you site to see if it was working and I didn’t get that error but only because it would appear that Hostgator has suspended your account. I’m guessing that this is because you have had further incursions from hackers, so I wanted to offer you a solution to your current hosting issue and future security issues by moving your site to my own Super Secure Hosting. I can get your site back up and running and you won’t ever have to worry about getting hacked again.

You can sign-up here if you are interested or email me if you have more questions:

https://supersecurehosting.com/signup/

If you have already registered the key and you’re not sure what email address it’s registered under then you can click on the green checkbox in the upper-right corner of the Anti-Malware Settings page in you wp-admin to open the registration form, then fill out the registration form with the email address you would like it to be registered under and re-register from there.