I think I have been hacked, I'm not sure, how do I check?

If your website is unexpectedly sending users to another website or causing a lot of popup windows, you would suspect it has been hacked. Now you want to know how the hacker "got in". Was it a flaw in SMF or in an SMF mod, was it a weak or leaked SMF password, or did they get in some other way that had nothing to do with SMF?

This could be difficult to figure out. First, put your SMF forum in maintenance mode -- at the bottom of Settings.php, add the line $maintenance = 2;. Later, when you are done checking things, you can remove that line. Search through your php files. Start with Settings.php and index.php. If the first line isn't "<?php" and absolutely nothing else, you've almost certainly been hacked. If you find the function base64_decode anywhere in your files, you have almost certainly been hacked. After you check Settings.php and index.php, check the files in Sources, and in any mod subdirectories. Check the php files in your themes.

Check the datestamps on your files. See which have been altered most recently. If you haven't installed mods or themes or edited your files, but some of them have recent timestamps, then someone other than you has modified them. Check for any "extra" files that shouldn't be there.

I am sure I have been hacked...what do I do now?

First of all, keep calm. When the forum has been hacked, there are a few simple steps the administrator can perform.

• Backup your database.
  Your files might be bad, but your database might still be good. If you had added $maintenance = 2; line to the bottom of your Settings.php file, remove it first.

• File a security report with SMF.
  If the hacker got in via a security weakness in SMF or an SMF mod and please report it to the SMF developers, so that the issue can be investigated and, if confirmed, patched. Please report Security issues here.
  To help the developers understand and solve the problem, please provide your webserver logs, and/or FTP logs. Usually, you can find these logs in your host's control panel, or in a directory called /logs in your account.

• Replace your SMF files. You will do this either from a recent backup, or else you will get a fresh set of files.
  • To be on the safe side, remove practically all of your SMF files
    • Make careful notes on any special customizations you have made to your php files.
    • Keep the attachements directory
    • Keep Settings.php
    • Keep any directories where you have stored other images or documents (such as the directory for a galley mod)
  • Restore a recent backup of your SMF files. But first, remove any "extra" files that are not part of SMF. To be on the safe side, you can remove practically all your SMF files, leaving only Settings.php, Settings_bak.php, and your attachments/avatars directory. If you have trouble removing any files, this could be related to running malware. Talk to your host about how to remove those files.
  • If you don't have a recent backup, or if you just want to start fresh, re-upload fresh SMF files.
    • Download a Large Upgrade Pack (Go to the download site) for the version of SMF that you're using.
    • Upload every file in the package, except the files required for upgrading (usually just upgrade.php and a few SQL files), using FTP; uploading may take a while. Once done, you'll have fresh files and can use your forum safely again.

I have cleared my hacked SMF installation, how can I prevent this from happening again?

This depends on how the hacker got in. Change your SMF administrator passwords. Change your FTP passwords. Change your account control panel password. Ask your host to check if any other websites on your server have been affected. Ask them to check the logs to see if they can figure out who might have had access to your server. Ask your host to check your file permissions. With some hosts, incorrect file permissions can leave files open for easier hacking. Find out if the hacker got in through your account, through your SMF forum, or some other way.

You can install a security modification (Go to the modification site) to enhance the forums security level. Depending on the modification's features, this can be more or less active against hackers.

Another measure that you can take is to apply some or all of these security tips. These tips help you to protect your forum from any further attacks.