Nir Valtman is an infosec professional who has released an open source anti-defacement tool called AntiDef, and wrote a publication about QRbot, an iPhone QR botnet POC he developed. His latest open source tool is Cloudefigo
He is a public speaker (spoke on BlackHat, DEF CON, OWASP, InfoSec etc.) and open source contributor.
https://www.blackhat.com/us-14/speakers/Nir-Valtman.html
https://www.defcon.org/html/defcon-23/dc-23-speakers.html
https://twitter.com/valtmanir
http://www.valtman.org/