Android Debug Bridge

About the speaker

Gabriel Cirlig
White Ops, London, UK

Software developer turned rogue, Gabi went from developing apps for small businesses to 2M+ DAU Facebook games and then hacking cars while keeping an eye for everything shiny and new. For about four years Gabriel shifted gears and started tinkering at Ixia’s threat intelligence system as a security researcher while speaking at various conferences (SAS, AVAR, PHDays) in his free time showcasing whatever random hardware he hacked. Fortunately after joining White Ops, he turned this into his full time position. With a background in electronics engineering and various programming languages, Gabi likes to dismantle and hopefully put back whatever he gets his hands on.

Abstract

Starting as a developer’s best friend, the Android Debug Bridge has turned into a security nightmare as time passed. While having an open port available for debugging over the internet sounds great, forgetting to turn off that service in production environment can spell big trouble for you or even your customers.

My analysis will be of the protocol, the worms abusing it and how I discovered it all after putting my freshly built honeypot up. The Android Debug Bridge protocol was initially designed for accessing various critical services of an Android device over USB. However, it also got encapsulated over TCP/IP recently, opening up port 5555 for a remote debugger to attach itself. From a security standpoint however, no improvements have been made, and a remote attacker can freely connect and exploit a device over the air. This is why I started developing a low interaction honeypot to catch this kind of attacks following a surge in hits on that specific port in our sensors. Shortly after, I opensourced the project on GitHub. This led in a huge surge of honeypots being open by fellow security researchers, and thus awareness about this vulnerability significantly increased. After also publishing a blogpost about one of the new threats that I found, Trinity (p2p bot that spread a miner), the amount of vulnerable devices dropped by 50%, from more than 44000 to around 22000.

In the first part of the presentation I’ll be discussing the development procedure for the honeypot from the ground up as well as dissecting the ADB protocol in order to enable researchers to more easily implement their own honeypots. The second part of the talk will be focused on exploring various strands of malware that have started hitting the honeypot in the last months, some that are even quite hilarious. From apologetic miners to aggressive peer to peer botnets, I’ll be showcasing the whole ecosystem of ADB worms that have circulated around the internet.