{"id":3595,"date":"2023-06-23T11:07:26","date_gmt":"2023-06-23T08:07:26","guid":{"rendered":"https:\/\/www.virtono.com\/community\/?p=3595"},"modified":"2023-06-22T14:09:25","modified_gmt":"2023-06-22T11:09:25","slug":"how-to-protect-your-server-against-brute-force-attacks","status":"publish","type":"post","link":"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/","title":{"rendered":"How to Protect Your Server Against Brute Force Attacks"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_73 counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#Introduction\" title=\"Introduction\">Introduction<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#What_is_a_Server_Brute_Force_Attack\" title=\"What is a Server Brute Force Attack\">What is a Server Brute Force Attack<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#How_to_Identify_Brute_Force_Attacks\" title=\"How to Identify Brute Force Attacks\">How to Identify Brute Force Attacks<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#How_to_Protect_Your_Server_Against_Brute_Force_Attacks\" title=\"How to Protect Your Server Against Brute Force Attacks\">How to Protect Your Server Against Brute Force Attacks<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#Step_1_Strong_passwords\" title=\"Step 1: Strong passwords\">Step 1: Strong passwords<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#Step_2_SSH_hardening\" title=\"Step 2: SSH hardening\">Step 2: SSH hardening<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#Step_3_Fail2Ban\" title=\"Step 3: Fail2Ban\">Step 3: Fail2Ban<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#Step_4_IP_whitelisting\" title=\"Step 4: IP whitelisting\">Step 4: IP whitelisting<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#Step_5_Limit_login_attempts\" title=\"Step 5: Limit login attempts\">Step 5: Limit login attempts<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#Step_6_Updates_and_patches\" title=\"Step 6: Updates and patches\">Step 6: Updates and patches<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#Step_7_Intrusion_Detection_System_IDS\" title=\"Step 7: Intrusion Detection System (IDS)\">Step 7: Intrusion Detection System (IDS)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/#Final_Thoughts\" title=\"Final Thoughts\">Final Thoughts<\/a><\/li><\/ul><\/nav><\/div>\n<h3 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"Introduction\"><\/span>Introduction<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Brute force attacks are one of the most common threats that server administrators face. This guide is designed to provide you with the knowledge and strategies you need to protect your server from brute force attacks.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"What_is_a_Server_Brute_Force_Attack\"><\/span>What is a Server Brute Force Attack<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>A <a href=\"https:\/\/www.virtono.com\/cloud-vps\">server<\/a> brute force attack is a type of cyber attack in which an attacker tries all possible username and password combinations until the correct combination is found. A brute force attack aims to bypass a server&#8217;s authentication mechanisms in order to gain control or extract sensitive information.<\/p>\n\n\n\n<p>In a server brute force attack, the attacker usually uses automated software tools or scripts to rapidly and repeatedly submit different username and password combinations to the server. These tools target vulnerabilities in weak or poorly implemented authentication systems, where the server may not have proper precautions in place to prevent or detect multiple login attempts.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"How_to_Identify_Brute_Force_Attacks\"><\/span>How to Identify Brute Force Attacks<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>You can look for certain signs or implement monitoring mechanisms to determine if a brute force attack is taking place. Here are a few methods for detecting brute force attacks:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Analyze server logs for an unusually high number of failed login attempts or a high number of login attempts from a single IP address. Brute force attacks frequently involve multiple login failures.<\/li>\n<\/ul>\n\n\n\n<p>You can find the server logs that contain information about login attempts in the following locations:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\/var\/log\/auth.log: This file typically contains authentication-related logs, including successful and failed login attempts.<\/li>\n\n\n\n<li>\/var\/log\/secure: Some Linux distributions use this file instead of auth.log to store authentication-related logs.<\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code has-white-color has-black-background-color has-text-color has-background\"><code>For auth.log: grep 'Failed password' \/var\/log\/auth.log<br>For secure log: grep 'Failed password' \/var\/log\/secure<\/code><\/pre>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"750\" height=\"314\" data-attachment-id=\"3596\" data-permalink=\"https:\/\/www.virtono.com\/community\/knowledgebase\/how-to-protect-your-server-against-brute-force-attacks\/attachment\/screenshot-2023-06-22-at-10-09-02\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-22-at-10.09.02.png?fit=2050%2C858&amp;ssl=1\" data-orig-size=\"2050,858\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"Screenshot-2023-06-22-at-10.09.02\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-22-at-10.09.02.png?fit=300%2C126&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-22-at-10.09.02.png?fit=750%2C314&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-22-at-10.09.02.png?resize=750%2C314&#038;ssl=1\" alt=\"How to Protect Your Server Against Brute Force Attacks\" class=\"wp-image-3596\" srcset=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-22-at-10.09.02.png?resize=1024%2C429&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-22-at-10.09.02.png?resize=300%2C126&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-22-at-10.09.02.png?resize=768%2C321&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-22-at-10.09.02.png?resize=1536%2C643&amp;ssl=1 1536w, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-22-at-10.09.02.png?resize=2048%2C857&amp;ssl=1 2048w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/figure>\n<\/div>\n\n\n<p><\/p>\n\n\n\n<p>Keep in mind that log file locations and naming conventions may differ depending on your Linux distribution and configuration. To ensure accurate log analysis, consult the documentation or check the specific log file configuration on your system.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Anomalies in user behavior: Keep an eye on user accounts that have unusual login patterns, such as multiple login attempts in a short period of time or attempts from unusual geographic locations.<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Analyze network traffic for patterns that indicate brute force attacks, such as a high volume of login requests or requests targeting specific user accounts.<\/li>\n\n\n\n<li>System performance: Due to the high volume of login attempts, brute force attacks can place a significant strain on servers. Keep an eye on system performance for any unusual spikes in resource usage that could indicate an ongoing attack.<\/li>\n<\/ul>\n\n\n\n<p><strong>Monitor CPU usage:<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Use the top command to view real-time information about system processes and their CPU usage.<\/li>\n\n\n\n<li>Look for processes consuming a high percentage of CPU resources or sustained high CPU usage over time.<\/li>\n\n\n\n<li>Press &#8220;q&#8221; to exit the top command.<\/li>\n<\/ol>\n\n\n\n<p><strong>Monitor memory usage:<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Use the free -m command to view memory usage in megabytes.<\/li>\n\n\n\n<li>Observe the &#8220;used&#8221; and &#8220;free&#8221; memory values and look for any significant fluctuations or consistently high memory usage.<\/li>\n<\/ol>\n\n\n\n<p><strong>Monitor network traffic:<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Use the iftop command to monitor real-time network traffic.<\/li>\n\n\n\n<li>Observe the incoming and outgoing traffic, particularly the source and destination IP addresses.<\/li>\n\n\n\n<li>Look for any unusual spikes in network activity or a high volume of connections from a single IP address.<\/li>\n<\/ol>\n\n\n\n<p>These steps will assist you in monitoring system performance and detecting possible signs of a brute force attack. To mitigate brute force attacks, use additional security measures such as <a href=\"https:\/\/www.virtono.com\/community\/tutorial-how-to\/how-to-install-and-configure-fail2ban-on-centos\/\">fail2ban<\/a> to automatically block suspicious IP addresses and implement strong password policies.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"How_to_Protect_Your_Server_Against_Brute_Force_Attacks\"><\/span>How to Protect Your Server Against Brute Force Attacks<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<h4 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"Step_1_Strong_passwords\"><\/span>Step 1: <strong>Strong passwords<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>For all user accounts on your server, enforce the use of strong passwords. Encourage users to create passwords that are long, complex, and one-of-a-kind. Consider implementing a password policy that requires a minimum length, uppercase and lowercase letters, numbers, and special characters.<\/p>\n\n\n\n<h4 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"Step_2_SSH_hardening\"><\/span>Step 2: SSH hardening<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>Securing your SSH (Secure Shell) service is important because it is a popular target for brute force attacks. To reduce automated scanning, change the default SSH port (typically 22) to a non-standard port. Additionally, instead of relying solely on passwords, disable root login and use key-based authentication.<\/p>\n\n\n\n<h4 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"Step_3_Fail2Ban\"><\/span>Step 3: Fail2Ban<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p><a href=\"https:\/\/www.virtono.com\/community\/tutorial-how-to\/how-to-install-and-configure-fail2ban-on-centos\/\">Install and configure Fail2Ban<\/a>, a log-parsing application that monitors log files and blocks suspicious IP addresses. Fail2Ban can automatically ban IP addresses that fail authentication or engage in other illegal activities.<\/p>\n\n\n\n<h4 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"Step_4_IP_whitelisting\"><\/span>Step 4: IP whitelisting<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>Configure your firewall to allow only trusted IP addresses or IP ranges access. This technique restricts server access, reducing the attack surface.<\/p>\n\n\n\n<h4 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"Step_5_Limit_login_attempts\"><\/span>Step 5: Limit login attempts<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>Implement mechanisms to limit the number of failed login attempts that can occur in a given time frame. In this regard, tools such as <a href=\"https:\/\/www.fail2ban.org\/wiki\/index.php\/Main_Page\" target=\"_blank\" rel=\"noopener\">Fail2Ban<\/a> can help, but you can also configure services such as SSH or web servers to enforce login attempt restrictions.<\/p>\n\n\n\n<h4 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"Step_6_Updates_and_patches\"><\/span>Step 6: Updates and patches<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>Apply security updates and patches to your Linux server&#8217;s operating system and installed software on a regular basis. Updating your system helps address vulnerabilities that attackers may exploit.<\/p>\n\n\n\n<h4 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"Step_7_Intrusion_Detection_System_IDS\"><\/span>Step 7: Intrusion Detection System (IDS)<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>Install an intrusion detection system (IDS) that can monitor your server for unusual activity or signs of a brute force attack. <a href=\"https:\/\/www.virtono.com\/community\/tutorial-how-to\/how-to-install-suricata-on-ubuntu-22-04\/\">Suricata<\/a> has tools that can analyze network traffic and generate alerts or take automated actions to prevent malicious activity.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-accent-color has-text-color\"><span class=\"ez-toc-section\" id=\"Final_Thoughts\"><\/span>Final Thoughts<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>A complex approach is required to protect your Linux server from brute force attacks. You can significantly improve your server&#8217;s defenses by implementing secure password policies, limiting remote access, using tools like Fail2ban and 2FA, and staying proactive with software updates and log analysis. Remember that server security is an ongoing process that requires regular monitoring and adaptation to evolving threats to ensure a secure environment.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Introduction Brute force attacks are one of the most common threats that server administrators face. This guide is designed to provide you with the knowledge and strategies you need to protect your server from brute force attacks. What is a Server Brute Force Attack A server brute force attack is<\/p>\n","protected":false},"author":8,"featured_media":3598,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[5],"tags":[519,521,520,524,522,523],"class_list":["post-3595","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-knowledgebase","tag-brute-force-attacks","tag-brute-force-protect","tag-check-brute-force","tag-limit-login-attempts","tag-protect-brute-force","tag-protect-your-server"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2023\/06\/How-to-Protect-Your-Server-Against-Brute-Force-Attacks.png?fit=600%2C330&ssl=1","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p7ISfL-VZ","jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":542,"url":"https:\/\/www.virtono.com\/community\/tutorial-how-to\/542\/","url_meta":{"origin":3595,"position":0},"title":"HOW TO INSTALL AND SET UP FAIL2BAN ON CENTOS SERVER","author":"Daniel Draga","date":"August 26, 2016","format":false,"excerpt":"Fail2ban software is an intrusion prevention framework on your CentOS 7 (and 6) vps that scans log files and bans IPs that show the malicious signs so you can protect your server from brute-force attacks. Some previously posted some including to change default SSH port and to disable root login\u2026","rel":"","context":"In &quot;Tutorials&quot;","block_context":{"text":"Tutorials","link":"https:\/\/www.virtono.com\/community\/category\/tutorial-how-to\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/08\/fail2ban.jpg?fit=784%2C313&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/08\/fail2ban.jpg?fit=784%2C313&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/08\/fail2ban.jpg?fit=784%2C313&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/08\/fail2ban.jpg?fit=784%2C313&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":1149,"url":"https:\/\/www.virtono.com\/community\/tutorial-how-to\/ssh-login-under-debian-with-fail2ban\/","url_meta":{"origin":3595,"position":1},"title":"SSH Login under Debian with fail2ban","author":"Shreyash Sharma","date":"October 22, 2017","format":false,"excerpt":"The tool\u00a0fail2ban\u00a0,\u00a0written in Python,\u00a0aims to secure server services against DoS attacks.\u00a0It checks log files for predefined patterns and temporarily blocks the corresponding IP addresses if the failed access is repeated.\u00a0This article shows you how to back up a Debian-based server with fail2ban.\u00a0The deployed version of fail2ban is\u00a00.9.6-2\u00a0under\u00a0Debian 9.1\u00a0. Problem In\u2026","rel":"","context":"In &quot;Tutorials&quot;","block_context":{"text":"Tutorials","link":"https:\/\/www.virtono.com\/community\/category\/tutorial-how-to\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2017\/10\/fail2ban-logo2.png?fit=459%2C441&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":732,"url":"https:\/\/www.virtono.com\/community\/knowledgebase\/hardening-the-defense-of-database-server\/","url_meta":{"origin":3595,"position":2},"title":"Hardening the Defense of Database Server","author":"Daniel Draga","date":"November 1, 2016","format":false,"excerpt":"Importance of Database Security: Databases often store sensitive data Incorrect data or loss of data could negatively affect business operations Databases can be used as bases to attack other systems from. \u00a0 Principles of Finding Holes Don't believe the documentation Implement your own client Debug the system to understand how\u2026","rel":"","context":"In &quot;Knowledgebase&quot;","block_context":{"text":"Knowledgebase","link":"https:\/\/www.virtono.com\/community\/category\/knowledgebase\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/11\/network-security1.jpg?fit=1200%2C556&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/11\/network-security1.jpg?fit=1200%2C556&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/11\/network-security1.jpg?fit=1200%2C556&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/11\/network-security1.jpg?fit=1200%2C556&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/11\/network-security1.jpg?fit=1200%2C556&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":1296,"url":"https:\/\/www.virtono.com\/community\/tutorial-how-to\/arm-apache-for-denial-of-service-attacks\/","url_meta":{"origin":3595,"position":3},"title":"Arm Apache for denial-of-service attacks","author":"Daniel Draga","date":"January 7, 2018","format":false,"excerpt":"A little thought experiment: You want to write a web server, so program a socket-based server.\u00a0When a browser connects to it and requests a file, it delivers it, the client terminates the connection, and everyone is satisfied.\u00a0But then suddenly there is a bug report from someone whose web server is\u2026","rel":"","context":"In &quot;Knowledgebase&quot;","block_context":{"text":"Knowledgebase","link":"https:\/\/www.virtono.com\/community\/category\/knowledgebase\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2018\/01\/ddos-attack-ex-100695385-large.jpg?fit=699%2C474&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2018\/01\/ddos-attack-ex-100695385-large.jpg?fit=699%2C474&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2018\/01\/ddos-attack-ex-100695385-large.jpg?fit=699%2C474&ssl=1&resize=525%2C300 1.5x"},"classes":[]},{"id":1158,"url":"https:\/\/www.virtono.com\/community\/tutorial-how-to\/openssh-public-key-authentication-under-ubuntu\/","url_meta":{"origin":3595,"position":4},"title":"OpenSSH public key authentication under Ubuntu","author":"Shreyash Sharma","date":"October 24, 2017","format":false,"excerpt":"This article shows how\u00a0SSH access is\u00a0configured\u00a0for\u00a0public-key\u00a0authentication\u00a0.\u00a0To do so, a key pair is created on the client, the public part of the keys are transferred to the server, and the server is set up for key authentication.\u00a0The user can log on to the server without a login password, only the password\u2026","rel":"","context":"In &quot;Tutorials&quot;","block_context":{"text":"Tutorials","link":"https:\/\/www.virtono.com\/community\/category\/tutorial-how-to\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":497,"url":"https:\/\/www.virtono.com\/community\/tutorial-how-to\/how-to-change-the-ssh-port-for-your-linux-based-server\/","url_meta":{"origin":3595,"position":5},"title":"How to Change the SSH Port for Your Linux Based Server","author":"Daniel Draga","date":"August 20, 2016","format":false,"excerpt":"Logging in, you might have noticed this, sometimes: \u00a0 You will notice that whenever you leave ssh on the standard port, attempted logins fill up your authorization logs. Changing to a different port will make it less frequent.This is because the vast majority of people hunting for any open ssh\u2026","rel":"","context":"In &quot;Tutorials&quot;","block_context":{"text":"Tutorials","link":"https:\/\/www.virtono.com\/community\/category\/tutorial-how-to\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/08\/Change-SSH-port-with-WHM-min.jpg?fit=800%2C450&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/08\/Change-SSH-port-with-WHM-min.jpg?fit=800%2C450&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/08\/Change-SSH-port-with-WHM-min.jpg?fit=800%2C450&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/08\/Change-SSH-port-with-WHM-min.jpg?fit=800%2C450&ssl=1&resize=700%2C400 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/posts\/3595","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/comments?post=3595"}],"version-history":[{"count":2,"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/posts\/3595\/revisions"}],"predecessor-version":[{"id":3607,"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/posts\/3595\/revisions\/3607"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/media\/3598"}],"wp:attachment":[{"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/media?parent=3595"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/categories?post=3595"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.virtono.com\/community\/wp-json\/wp\/v2\/tags?post=3595"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}