Recently HackerGiraffe and j3ws3r hijacked more than 70,000 Chromecasts to make people aware about the security risks of devices exposed to internet and promoted Pewdiepie.

They took advantage of exposed UPnP ports of home routers to hijack Chromecast devices and play their content.

Inspired from this hack, thewhiteh4t has created killcast, an open source tool for testing and research purposes, it’s available on GitHub, if you have a Google Home or Chromecast you can test and learn how simple it is to manipulate these devices if they are exposed or if you are in the same network.

What Happened

Almost all routers have UPnP enabled by default but home routers are not supposed to be exposed publicly, but in this case thousands of such routers were visible on Shodan, a search engine that lets user find specific types of devices exposed publicly.

Chromecast has two protocols, DIAL Protocol over SSDP and mDNS Server.

DIAL – DIscovery And Launch is a protocol that devices use to discover and launch apps from other devices.

SSDP – Simple Service Discovery Protocol is the basis of discovery protocol of UPnP and is intended for use in residential and small office environments.

A web-server runs on port 8008, and if you send specific GET, POST or DELETE requests, you can easily manipulate Chromecast devices, for exact requests you can study the python file in killcast.

Features

At the time of writing killcast performs 5 actions :

• Extract Interesting Information such as Build Version, Country, Timezone etc
• Rename Device
• Reboot Device
• Perform Factory Reset
• Kill Active Applications such as Youtube

Killcast is unable to play YouTube videos on demand like CastHack because as soon as CastHack attack was launched, Google released a Hotfix.

Installation

Killcast is a python3 script and works on popular linux distro like Kali Linux and Ubuntu, you can also run killcast on Termux for android.

Installation is very simple and requires python3 and requests module.

xgit clone https://github.com/thewhiteh4t/killcast.git
cd killcast
apt-get install python3
pip install requests

Usage

python3 killcast.py -h
usage: killcast.py [-h] –t IP
Manipulate Chromecast Devices in your Network
optional arguments:
-h, –help   show this help message and exit
 –t IP, —ip IP  IP Address of Chromecast

python3 killcast.py -t 192.168.0.100

Demo