英文摘要 |
The safety of the financial system is the basis for the stable development of the economy. However, it is often exposed to various risks and threats. Therefore, it is an important basis for the financial industry to accurately identify and prevent risks as well as hidden dangers.
With the widespread application and rapid development of information systems in the financial industry, financial institutions are also facing increasingly serious information technology risks, especially the risks caused by staff intentionally or unintentionally, which have always been considered as one of the major security vulnerabilities of the information systems. To this end, supervision authorities have been promoting laws, regulations, and guidelines to optimize the risk prevention mechanisms, and financial institutions have been formulating security policies and established corresponding risk detection mechanisms based on their businesses to prevent such risks and threats. However, it is still a major challenge for financial institutions to effectively detect and prevent known threats and more importantly unknown risks with valid security policies.
To address these challenges, this dissertation proposes a framework for the detection of staff abnormal behavior in the financial information system. The key idea is to extract baselines for determining abnormal behavior from the code of behavior in security policies and behavior patterns embodied in behavior records, represent the normal and abnormal behavior of the staff through complex events, and to mine the behavior rules of their behavior through human-computer interaction and collaboration between the computer and the risk control officer. On this basis, the computer system can realize the risk identification and evaluation of abnormal behaviors and form interactive feedback of the detected behavior and the security policy. This dissertation focuses on the detection, analysis, and demonstration application of staff abnormal behavior in the financial industry.
First of all, we propose a rule-based representation of the baseline for determining abnormal behavior of staff: at the knowledge-level, the provisions in security policies that reflect the norms of behavior are represented as compliance rules and transformed into violations of security policies, At the factual level, the normal behavior pattern of staff reflected in the record of their behavior is expressed as a behavior rule and transformed into a deviant behavior that does not conform to it.
Secondly, combining the rule representation of the baseline for determining abnormal behavior of staff, we apply the representation method of complex events processing and proposes a representation model of staff behavior for financial institutions: a specific activity is represented as a primitive event, for the code of behavior in security policies, the risk control officer understand the code of behavior and establish compliance rules that meet its provisions and convert it into a violation representation, for the normal behavior patterns embodied in behavior records, data mining algorithms are used to mine the normal behavior patterns from the historical records of staff and convert them into deviant behavior that does not conform to them.
Then, based on the two types of abnormal behavior baselines, a rule engine is used to detect whether the behavior of staff violates the code of behavior, and realize the detection of known abnormalities, some classical data mining algorithms are used to compare the newly generated records of behavior with the normal behavior patterns and identify deviations from the normal behavior patterns that may be unknown abnormalities.
In addition, to further improve the accuracy of the identification of the unknown anomaly, we put an interactive approach for unknown anomaly identification based on the experience of the risk control officer: through collecting assessment opinions of the risk control officer in the process of unknown risk identification, a feedback model for unknown anomaly identification can be established, and we can continuously optimize the configuration of the data mining algorithm and improve the efficiency of anomaly identification.
Finally, design and develop a staff anomaly detection prototype system that consists of some key technologies such as complex event-based behavior representation, complex event detection and processing, interactive feedback, and visual analysis. The application system has been verified and demonstrated in a commercial bank's data center and achieved expected results in actual business practices. |