added CTFs resources

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

README.md

@@ -621,6 +621,7 @@ Linux Security Expert</b></a> - trainings, howtos, checklists, security tools an
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://gtfobins.github.io/"><b>GTFOBins</b></a> - list of Unix binaries that can be exploited by an attacker to bypass local security restrictions.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://guif.re/"><b>Guifre Ruiz Notes</b></a> - collection of security, system, network and pentest cheatsheets.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="http://blog.safebuff.com/2016/07/03/SSRF-Tips/index.html"><b>SSRF Tips</b></a> - a collection of SSRF Tips.<br>
+&nbsp;&nbsp;:small_orange_diamond: <a href="http://shell-storm.org/repo/CTF/"><b>shell-storm repo CTF</b></a> - great archive of CTFs.<br>
 </p>
 
 ##### :black_small_square: Bounty programs
@@ -649,7 +650,7 @@ Linux Security Expert</b></a> - trainings, howtos, checklists, security tools an
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://github.com/amolnaik4/bodhi"><b>Bodhi</b></a> - is a playground focused on learning the exploitation of client-side web vulnerabilities.<br>
 </p>
 
-##### :black_small_square: Labs (ethical hacking platforms/trainings)
+##### :black_small_square: Labs (ethical hacking platforms/trainings/CTFs)
 
 <p>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://www.offensive-security.com/"><b>Offensive Security</b></a> - true performance-based penetration testing training for over a decade.<br>
@@ -657,6 +658,8 @@ Linux Security Expert</b></a> - trainings, howtos, checklists, security tools an
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://www.hacking-lab.com/index.html"><b>Hacking-Lab</b></a> - online ethical hacking, computer network and security challenge platform.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="http://pwnable.kr/index.php"><b>pwnable.kr</b></a> - non-commercial wargame site which provides various pwn challenges regarding system exploitation.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://pwnable.tw/"><b>Pwnable.tw</b></a> - is a wargame site for hackers to test and expand their binary exploiting skills.<br>
+&nbsp;&nbsp;:small_orange_diamond: <a href="https://picoctf.com/"><b>picoCTF</b></a> - is a free computer security game targeted at middle and high school students.<br>
+&nbsp;&nbsp;:small_orange_diamond: <a href="https://ctflearn.com/"><b>CTFlearn</b></a> - is an online platform built to help ethical hackers learn and practice their cybersecurity knowledge and skills.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://silesiasecuritylab.com/"><b>Silesia Security Lab</b></a> - high quality security testing services.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://practicalpentestlabs.com/"><b>Practical Pentest Labs</b></a> - pentest lab, take your Hacking skills to the next level.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://www.root-me.org/?lang=en"><b>Root Me</b></a> - the fast, easy, and affordable way to train your hacking skills.<br>