B374k.php ((new))

Attackers use this tool because it packs a comprehensive suite of "features" into a single file to maintain access and escalate control:

🔧 Core Features of b374k Shell

1. File Management

The B374K PHP shell poses significant security risks if not used properly. Some of the security concerns associated with this tool include:

Ironically, some versions of b374k themselves have security flaws. For instance, version 3.2.3 was found to be vulnerable to Cross-Site Request Forgery (CSRF) b374k.php

The attacker felt invisible, but they left marks. A Security Operations Center (SOC) analyst noticed a spike in POST requests coming from an unfamiliar IP address targeting a single file in the uploads folder. Using tools like Splunk and THOR Lite, the analyst scanned the server and flagged the file’s signature. The End: Eviction

Don’t let that file be b374k.php. Audit your servers today. You might be surprised at what you find hiding in /wp-content/uploads/2019/05/. Attackers use this tool because it packs a

2. File Identification

| Attribute | Details | | :--- | :--- | | Filename | b374k.php (can be renamed to any .php, .php5, .phtml, etc.) | | Typical Size | 10KB – 200KB (depending on version and obfuscation) | | File Hash (Example) | 7a3e7f9b8c2d1a5e6f4g8h2i3j4k5l6m (varies by version) | | First Seen | ~2012 (still actively used in 2025) |

We are also seeing the rise of AI-generated variants. Attackers feed the b374k source code into ChatGPT or CodeLlama and ask it to "rewrite this without changing functionality, but using different variable names." This easily defeats signature-based antivirus. Browse, upload, download, edit, delete, rename, copy, move

John contacted the VPN provider and requested that they provide him with the attacker's IP address. The provider complied, and John was able to identify the attacker's location.