The recent media attention surrounding Google’s admission that actors originating from China attacked its network highlights an apparent problem plaguing any cyber defense posture. In the aftermath of Google’s announcements commentators and experts alike lamented the difficulty of assigning direct attribution for the attacks to the Chinese military or its government. Conventional wisdom dictates that it is nearly impossible to assign attribution of a cyber attacker. According to this school of thought the open nature of the Internet allows an attacker to spoof their IP address and obfuscate their identity by routing through a series of proxy servers or utilizing a botnet. Further, it is believed that even with the technical capacity to accurately trace the origin of an attack, it is impossible with current technology to know who is at the keyboard executing the attack.
As the attribution problem is central to a number of vexing cyber security predicaments, it is important to study and validate the assumption that attribution is nearly impossible. While it is technically difficult to trace the origin of attack through a confusing maze of proxy servers or infected bots, attribution is not solely dependent on the technology needed to identify an accurate IP address.
A number of others technical and non-technical data points can help identify the source of an attack. For example, if the source of an attack is a bot investigators can attempt to identify who wrote the bot code and who currently controls the bot. In the summer of 2008 a large botnet was used to launch DDoS attacks against targets in Georgia. While the use of a botnet appeared to complicate the task of identifying those responsible for the attack, a closer examination revealed that the botnet used during the attack was known as “Machbot”. According to Arbor Network’s Danny McPherson, “Machbot is primarily a Web-based Russian DDOS botnet written in Russian, used by several different groups, but not widely available.” While the identification of the botnet used for the attacks on Georgia does not provide irrefutable proof of Russia’s responsibility for the attacks, it certainly does provide compelling evidence that Russian nationalist hackers and possibly the Russian government were involved in these attacks.
Additionally, analyzing the attacker’s target may help reveal his or her identity. The target of the attack reveals information about the intentions of the attacker and can therefore aid in attribution. Returning to the example of the cyber attacks against Georgia, the corresponding phsyical conflict between Russian and Georgian troops in South Ossetia led many analyst to suspect that Russian nationalist hackers, possibly at the direction of the Russian Government, were responsible for the DDoS against Georgian websites.
Finally, patient and clever cyber intelligence gathering can reveal a tremendous amount of information the individuals or entities responsible for an attack. After the presence of the Ghostnet cyber espionage network was revealed by the Citizen Lab at the University of Toronto, Heike and Jumper from the Dark Visitor blog demonstrated that patient cyber intelligence gathering can aid in attribution. Specifically, via clever analysis of whois registration data and patient trolling of chinese hacker forums, Heike and Jumper were able to identify at least one individual believed to be responsible for the Ghostnet cyber espionage network.
In short, it vitally important to understand that attribution is difficult, but not impossible. There may not be fancy technology that can discover the origination point of an attack and identify the individual at the keyboard. However, through patience and old school detective work it is possible to identify the hackers, criminals, spies, or terrorists responsible for a cyber attack.