ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
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Filtering by
- All Subjects: Threat Intelligence
- Creators: Ahn, Gail-Joon
attacks. However, this task is difficult for a variety of reasons. In simple terms, it is difficult
to determine who the attacker is, what the desired goals are of the attacker, and how they will
carry out their attacks. These three questions essentially entail understanding the attacker’s
use of deception, the capabilities available, and the intent of launching the attack. These
three issues are highly inter-related. If an adversary can hide their intent, they can better
deceive a defender. If an adversary’s capabilities are not well understood, then determining
what their goals are becomes difficult as the defender is uncertain if they have the necessary
tools to accomplish them. However, the understanding of these aspects are also mutually
supportive. If we have a clear picture of capabilities, intent can better be deciphered. If we
understand intent and capabilities, a defender may be able to see through deception schemes.
In this dissertation, I present three pieces of work to tackle these questions to obtain
a better understanding of cyber threats. First, we introduce a new reasoning framework
to address deception. We evaluate the framework by building a dataset from DEFCON
capture-the-flag exercise to identify the person or group responsible for a cyber attack.
We demonstrate that the framework not only handles cases of deception but also provides
transparent decision making in identifying the threat actor. The second task uses a cognitive
learning model to determine the intent – goals of the threat actor on the target system.
The third task looks at understanding the capabilities of threat actors to target systems by
identifying at-risk systems from hacker discussions on darkweb websites. To achieve this
task we gather discussions from more than 300 darkweb websites relating to malicious
hacking.
To overcome above issue, I explain the necessity of determining how likely a reported indicator is malicious given the evidence and prioritizing it based on such determination. Confidence Score Measurement system (CSM) introduces the concept of confidence score, where it assigns a score of being malicious to a threat indicator based on the evaluation of different threat intelligence systems. An indicator propagates maliciousness to adjacent indicators based on relationship determined from behavior of an indicator. The propagation algorithm derives final confidence to determine overall maliciousness of the threat indicator. CSM can prioritize the indicators based on confidence score; however, an analyst may not be interested in the entire result set, so CSM narrows down the results based on the analyst-driven input. To this end, CSM introduces the concept of relevance score, where it combines the confidence score with analyst-driven search by applying full-text search techniques. It prioritizes the results based on relevance score to provide meaningful results to the analyst. The analysis shows the propagation algorithm of CSM linearly scales with larger datasets and achieves 92% accuracy in determining threat indicators. The evaluation of the result demonstrates the effectiveness and practicality of the approach.