Crude solution to ban bots by their user-agent

Okay, this is a very crude way to block bots, spiders and crawlers by their user-agent, but so far, this has been very, very efficient.

Even when one chooses ” yes “, the question will be repeated. This is not a problem, because no one in their right mind is going to add “bot”, “spider” or “crawler” as their user-agent.

So here’s the PHP script that I rammed into a certain website to prevent it from being DDOSsed by (malicious) bots.

<?php

// Emergency bypass
// goto end;

/////////////////////////////////////////////////////////////
// (c) FoxSAIn 2023, Free to use.
/////////////////////////////////////////////////////////////

// Function to check if the user agent appears to be a bot or spider.
// Enter the bots you would like to block in a list as shown below.
function isBot()
{
    $user_agent = $_SERVER["HTTP_USER_AGENT"];
    $bot_keywords = [
        "bytespider",
        "amazonbot",
        "mj12bot",
        "YandexBot",
        "SemrushBot",
        "AhrefsBot"
    ];

    foreach ($bot_keywords as $keyword) {
        if (stripos($user_agent, $keyword) !== false) {
            return true;
        }
    }

    return false;
}

// Check if the visitor is a bot or spider
if (isBot()) {
    // This visitor appears to be a bot or spider, so display a choice.
    // Check if the choice form is submitted
    if (isset($_POST["submit"])) {
        // Check the choice made by the visitor
        $choice = isset($_POST["choice"]) ? $_POST["choice"] : "";

        if ($choice === "yes") {
            // User selected "Yes," block access
            echo "Access denied. If you believe this is an error, please contact us by writing the word support before the at sign, followed by 4-stroke.net";
        } elseif ($choice === "no") {
            // User selected "No," proceed to end
            goto end;
        }
    } else {
        // Output the message to the user and make the choice mandatory
        echo "Your user agent suggests you might be a bot, spider, or crawler. Are you one of these three?";

        // Output the radio button choices within a form
        echo '</p>
<form method="post" action="">';
        echo ' <label><input type="radio" name="choice" value="yes" required>Yes</label>';
        echo ' <label><input type="radio" name="choice" value="no">No</label>';
        echo ' <button type="submit" name="submit">Proceed</button>';
        echo "</form>
<p>";
    }

    // Exit to prevent further processing
    exit();
}
end:
// Original website code starts from here.
/////////////////////////////////////////////////////////////
?>

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A working Apache2 server with PHP7.4

I was in need of a server solution that could be quickly deployed as a VM.

      1. Install Debian 11 as a VM with web- and SSH server
      2. Create a USER next to your root account during the installation
      3. Find the IP address of the new installation. The easiest is if you have NoVNC running. Log in as USER and type
        ip a
      4. Time to so the sudo thing
        su

        log in as root

        apt-get update && apt-get install -y sudo
        usermod -aG sudo USER
        exit
        exit

        log back in as USER

      5. Okay, let’s install some more stuff but first we do an update
        sudo apt-get update && sudo apt-get upgrade -y

        Now we want some essentials

        sudo apt-get install -y dirmngr gnupg2 nano wget gpg curl fail2ban ufw software-properties-common

        Preparing the PHP install

        wget -q https://packages.sury.org/php/apt.gpg -O- | sudo apt-key add -
        echo "deb https://packages.sury.org/php/ $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/php.list
        sudo apt-get update
        sudo apt-get install -y php7.4 libapache2-mod-php7.4 php7.4-mysql php7.4-curl php7.4-gd php7.4-mbstring php7.4-xml php7.4-xmlrpc php7.4-zip

        And restart the Apache2 Webserver

        sudo systemctl restart apache2
      6. Alright, that’s done. Next step is to test things.
        sudo nano /var/www/html/test.php

        Enter this into the php file and press Control X and type Y to save and exit.

        <?php
        // Show all PHP information
        phpinfo();
        ?>
      7. Go to the IP address of the server you just created and type
        HTTP://IP ADDRESS/test.php
        

        If you see a PHP page with all sorts of data, you’re good. If not, go fix. Don’t ask me, I’m not there yet!

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How to correct the Themler crash after updating to Joomla 3.9

If you updated to the latest version and the following error appears when you try to launch Themler please follow the instruction below:

Fatal error: require_once(): Failed opening required '[...]/administrator/includes/toolbar.php' (include_path='.:/usr/lib/php7.2') in [...]/templates/[theme_name]/app/index.php on line 25

  1. Open theme folder on the server: www/Joomla_directory/templates;
  2. open /app folder;
  3. open index.php for editing in any html or text editor;
  4. find the line
    require_once JPATH_BASE . DS . 'includes' . DS . 'toolbar.php';
    and replace it with the following line:
    $prefix = version_compare(JVERSION, '3.9', '>=') ? 'sub' : '';
    require_once JPATH_BASE . DS . 'includes' . DS . $prefix . 'toolbar.php';
  5. open /app/start folder;
  6. open data.php file for editing and follow step 4;
  7. open manifest.php file for editing and follow step 4;
  8. start Themler.

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Force a file scan in NextCloud

To force a scan after a manual file transfer, for example, can be done as follows:

sudo -u [USER] php occ files:scan --all

for example:

sudo -u john php occ files:scan --all
Usage:
  files:scan [-p|--path="..."] [-q|--quiet] [-v|vv|vvv --verbose] [--all]
  [user_id1] ... [user_idN]

Arguments:
  user_id               will rescan all files of the given user(s)

Options:
  --path                limit rescan to the user/path given
  --all                 will rescan all files of all known users
  --quiet               suppress any output
  --verbose             files and directories being processed are shown
                        additionally during scanning
  --unscanned           scan only previously unscanned files

Source: https://docs.nextcloud.com/server/15/admin_manual/configuration_server/occ_command.html

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Upgrade to PHP7.2

  1. apt-get install apt-transport-https lsb-release ca-certificates
  2. wget -O /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg
  3. sh -c 'echo "deb https://packages.sury.org/php/ $(lsb_release -sc) main" > /etc/apt/sources.list.d/php.list'
  4. apt-get update
  5. apt-get install php7.2-common libapache2-mod-php7.2 php7.2-cgi php7.2-cli php7.2-phpdbg php7.2-fpm libphp7.2-embed php7.2-dev php7.2-curl php7.2-gd php7.2-imap php7.2-interbase php7.2-intl php7.2-ldap php7.2-readline php7.2-odbc php7.2-pgsql php7.2-pspell php7.2-recode php7.2-tidy php7.2-xmlrpc php7.2 php7.2-json php-all-dev php7.2-sybase php7.2-sqlite3 php7.2-mysql php7.2-opcache php7.2-bz2 libapache2-mod-php7.2 php7.2-mbstring php7.2-pdo php7.2-dom php7.2-enchant php7.2-gmp php7.2-soap php7.2-zip

In case you need mcrypt:

  1. apt-get -y install gcc make autoconf libc-dev pkg-config
  2. apt-get -y install libmcrypt-dev
  3. apt-get install php7.2-dev
  4. pecl install mcrypt-1.0.1

    When you see the prompt “libmcrypt prefix? [autodetect] :” -> Press [Enter] to autodetect

  5. php -i | grep "mcrypt"

  1. a2dismod php7.0

    *or whatever version you are upgrading from)

  2. a2enmod php7.2

 

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