added '50M_CTF_Writeup'

- signed-off-by: trimstray <trimstray@gmail.com>

README.md

@@ -686,6 +686,7 @@ performance of any of your sites from across the globe.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://dfir.it/blog/2015/08/12/webshell-every-time-the-same-purpose/"><b>Webshells</b></a> - great series about malicious payloads.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://portswigger.net/blog/practical-web-cache-poisoning"><b>Practical Web Cache Poisoning</b></a> - show you how to compromise websites by using esoteric web features.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://medium.com/@_bl4de/hidden-directories-and-files-as-a-source-of-sensitive-information-about-web-application-84e5c534e5ad"><b>Hidden directories and files</b></a> - as a source of sensitive information about web application.<br>
+&nbsp;&nbsp;:small_orange_diamond: <a href="https://github.com/manoelt/50M_CTF_Writeup"><b>50M_CTF_Writeup</b></a> - $50 million CTF from Hackerone - writeup.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://www.netsparker.com/security-cookies-whitepaper/"><b>Security Cookies</b></a> - this paper will take a close look at cookie security.<br>
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