(IJCSIS) International Journal of Computer Science and Information Security, Vol. 17, No. 5, May 2019 Botnet Detection and Prevention in Software Deļ¬ned Networks (SDN) using DNS Protocol Paper By Muhammad Junaid Zafar,Riphah International University, Islamabad, Pakistan mjunaidzafar@hotmail.com, Professor Dr. Muhammad Zubair, Riphah International University, Islamabad, Pakistan m.zubair@riphah.edu.pk International Journal of Computer Science and Information Security (IJCSIS), Vol. 17, No. 5, May 2019 23 https://sites.google.com/site/ijcsis/ ISSN 1947-5500