Public health debates have endured for hundreds of years involving questions like when and how should people be notified of health issues and epidemics? Or, what is the best way to generate positive action without inducing panic?
Today, those same kinds of questions are being directed at the relatively new area of public cyberhealth management. In fact, the recent campaign to eradicate CryptoLocker Ransomware and Gameover Zeus was one of the first and largest experiments of its kind in cyberhealth notification and inoculation.
On June 2, the US Department of Justice announced a global operation to dismantle GameOver Zeus and CryptoLocker -- but not before hundreds of thousands of users were infected and victim losses exceeded $100 million in the US alone. The announcement included a warning for victims to clean their infected computers within two weeks, the estimated time it might take for the botmasters to resurface.
Managing mass cyber infections is challenging. Our adversaries are well funded, agile, and adaptive. They are also constantly seeking the next weakness to exploit. Clean-up operations require broad global cooperation from law enforcement, domain registrars, security vendors, sinkhole operators, and most importantly, victims -- who must largely "opt-in."
The DOJ effort aimed at disrupting GameOver Zeus and CryptoLocker is a blueprint for good public cyberhealth. Consider the template:
Infected users are asked to remedy their infected systems
As past botnet cleanup efforts have shown, user awareness of mass infections is short lived. Therefore, it is crucial that remediation tools and solutions be provided on day zero. With the first announcement of the botnet taken offline, the public was directed to cleanup tools from every major security vendor. In addition, users could find solutions via a list curated by US-CERT or Get Safe Online.
Registries either block or sinkhole domain-generation algorithm (DGA) elements of the infections
This came in response to a letter by ICANN supporting the policy-based blocking of malicious domain registries. The malware uses seven top-level domains: .com, .net, .biz, .info, .co.uk, and .ru. All but the last two are being blocked, while domains under .co.uk and .ru are pointing to sinkholes.
Remediation is approached as a mass infection that must be managed -- not completely taken down
As Code Red and Conficker have shown, eliminating every last viral installation may be virtually impossible; tthere are still thousands of hosts on the Internet today infected by Code Red and Conficker. The size and impact of some infections may require perpetual blocking and sinkholing. Bottom line: Botnets must be managed as mass infections, and cleanup as an opt-in experience.
The cleanup effort addresses a peer-to-peer (P2P) component of the malware infrastructure
The remediation of P2P networks has been explored in academic papers, but this is one of the larger, IP-based sinkhole efforts to date.
The evolution of cyber public health requires coordinated defenses across our community. But just as importantly, these efforts must continue to improve and evolve as our understanding of cyberthreats grows.