192.168.1.102 - - [28/May/2026:14:52:16 +0000] "GET /b374k.php HTTP/1.1" 200 2125 "Mozilla/5.0..." Use code with caution.
Security analysts look for standard files returning an HTTP 200 OK status code in directories that should strictly store static images or documents. Static Code and Signature Analysis
Attackers can execute port scans, initiate reverse shells to connect back to their own machines, or use the server as a proxy to launch attacks on other networks.
Your web root should be owned by a non-privileged user, not www-data . Files: 644 . Directories: 755 . Never use 777 . Additionally, ensure www-data cannot write to any directory except a specific uploads temp folder.
The attacker had also used the shell to steal sensitive data, including database credentials and server configuration files. John knew that he had to act fast to prevent the attacker from using the stolen data to launch further attacks.
b374k’s feature set is extensive. According to its official documentation, it includes:
Outdated Content Management Systems (CMS) like WordPress, Joomla, or Drupal, along with vulnerable plugins, often suffer from Remote Code Execution (RCE) or Local File Inclusion (LFI) flaws that allow remote file creation.
: Attackers can browse the entire directory tree of the host machine, download sensitive files (like database configurations), upload additional malware, modify file permissions (chmod), and edit source code directly in the browser.
: Flaws in Content Management System (CMS) plugins, themes, or core components that allow remote attackers to force the server to download or create files.
: Spotting b374k.php , b374k_v3.php , or random alphanumeric variants in public directories (like /images/ or /uploads/ ) is a definitive indicator of a compromise.
Attackers rarely use b374k in its raw form. Instead, they leverage a packaging script that allows them to generate customized shells tailored to their specific needs. This packer offers attackers several configuration options including output filename, password protection, optional feature modules (convert, database, info, mail, network, processes), theme selection, and code obfuscation techniques such as base64 encoding and compression.
192.168.1.102 - - [26/May/2026:14:52:16 +0000] "GET /b374k.php HTTP/1.1" 200 2125 "Mozilla/5.0" Use code with caution. Key Indicators of Compromise (IoCs):
The attacker accessed the honeypot, and John was able to track their movements. He discovered that the attacker was using a VPN to hide their IP address, but he was able to identify the VPN provider.
Create a YARA rule to detect b374k by its variable names and function calls. For example, b374k contains unique strings like "function b374k_auth" or "case 'sec_download_image'" .