  Many security issues have come to the fore with the increasingly widespread
adoption of Internet-of-Things (IoT) devices. The Mirai attack on Dyn DNS
service, in which vulnerable IoT devices such as IP cameras, DVRs and routers
were infected and used to propagate large-scale DDoS attacks, is one of the
more prominent recent examples. IoT botnets, consisting of
hundreds-of-thousands of bots, are currently present ``in-the-wild'' at least
and are only expected to grow in the future, with the potential to cause
significant network downtimes and financial losses to network companies. We
propose, therefore, to build testbeds for evaluating IoT botnets and design
suitable mitigation techniques against them. A DETERlab-based IoT botnet
testbed is presented in this work. The testbed is built in a secure contained
environment and includes ancillary services such as DHCP, DNS as well as botnet
infrastructure including CnC and scanListen/loading servers. Developing an IoT
botnet testbed presented us with some unique challenges which are different
from those encountered in non-IoT botnet testbeds and we highlight them in this
paper. Further, we point out the important features of our testbed and
illustrate some of its capabilities through experimental results.
