Try to bypass my security measure on this site! http://165.227.106.113/header.php
Solution:
The site tell you the user agent is wrong when you go there and in the html comment you see Sup3rS3cr3tAg3nt
So you can either use the webtools to change the user agent or you can use curl
curl -A "user-agent-name-here" [URL]
curl -A "Sup3rS3cr3tAg3nt" http://165.227.106.113/header.php
Response: Sorry, it seems as if you did not just come from the site, “awesomesauce.com”.
Change the referer.
curl -A "Sup3rS3cr3tAg3nt" http://165.227.106.113/header.php -H "Referer: awesomesauce.com"
And success: Here is your flag: flag{did_this_m3ss_with_y0ur_h34d}
Flag: flag{did_this_m3ss_with_y0ur_h34d}