A Practical Approach for Taking Down Avalanche Botnets Under Real-World Constraints

Victor Le Pochat, Tim Van hamme, Sourena Maroofi, Tom Van Goethem, Davy Preuveneers, Andrzej Duda, Wouter Joosen, Maciej Korczyński

Presented at 27th Annual Network and Distributed System Security Symposium (NDSS 2020)

In 2016, law enforcement dismantled the infrastructure of the Avalanche bulletproof hosting service, the largest takedown of a cybercrime operation so far. The malware families supported by Avalanche use Domain Generation Algorithms (DGAs) to generate random domain names for controlling their botnets. The takedown proactively targets these presumably malicious domains; however, as coincidental collisions with legitimate domains are possible, investigators must first classify domains to prevent undesirable harm to website owners and botnet victims. The constraints of this real-world takedown (proactive decisions without access to malware activity, no bulk patterns and no active connections) mean that approaches from the state of the art cannot be applied. The problem of classifying thousands of registered DGA domain names therefore required an extensive, painstaking manual effort by law enforcement investigators. To significantly reduce this effort without compromising correctness, we develop a model that automates the classification. Through a synergetic approach, we achieve an accuracy of 97.6% with ground truth from the 2017 and 2018 Avalanche takedowns; for the 2019 takedown, this translates into a reduction of 76.9% in manual investigation effort. Furthermore, we interpret the model to provide investigators with insights into how benign and malicious domains differ in behavior, which features and data sources are most important, and how the model can be applied according to the practical requirements of a real-world takedown.

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DOI: 10.14722/ndss.2020.24161

BibTeX:

@inproceedings{LePochat2020avalanche,
author = "{Le Pochat}, Victor and {Van hamme}, Tim and Maroofi, Sourena and {Van Goethem}, Tom and Preuveneers, Davy and Duda, Andrzej and Joosen, Wouter and Korczy\'{n}ski, Maciej",
title = "A Practical Approach for Taking Down Avalanche Botnets Under Real-World Constraints",
booktitle = {Proceedings of the 27th Annual Network and Distributed System Security Symposium},
series = {NDSS 2020},
year = 2020,
doi = {10.14722/ndss.2020.24161},
}