Fuzzing is arguably the most practical approach for detecting security bugs in software, but a non-trivial extent of efforts is required for its adoption. To be effective, high-quality fuzz drivers should be first formulated with a proper sequence of APIs that can exhaustively explore the program states. To alleviate this burden, existing solutions attempt to generate fuzz drivers either by inferring the valid sequences of APIs from the consumer code (i.e., actual uses of APIs) or by directly extracting them from sample executions. Unfortunately, all existing approaches suffer from a common problem: the observed API sequences, either statically inferred or dynamically monitored, are intermingled with custom application logics. However, we observed that the unit tests are carefully crafted by the actual designer of the APIs to validate their proper usages, and importantly, it is a common practice to write the unit tests during their development (e.g., over 70% of popular GitHub projects).In this paper, we propose, UTopia, an open-source tool and analysis algorithm that can automatically synthesize effective fuzz drivers from existing unit tests with near-zero human involvement. To demonstrate its effectiveness, we applied UTopia to 55 open-source project libraries, including Tizen and Node.js, and automatically generated 5K fuzz drivers from 8K eligible unit tests. In addition, we executed the generated fuzzers for approximately 5 million per-core hours and discovered 123 bugs. More importantly, 2.4K of the generated fuzz drivers were adopted to the continuous integration process of the Tizen project, indicating the quality of the synthesized fuzz driver. The proposed tool and results are publicly available and maintained for a broader adoption among both researchers and practitioners.

Twitter is a popular public source for threat hunting. Many security vendors and security professionals use Twitter in practice for collecting Indicators of Compromise (IOCs). However, little is known about IOCs on Twitter. Their important characteristics such as earliness, uniqueness, and accuracy have never been investigated. Moreover, how to extract IOCs from Twitter with high accuracy is not obvious. In this paper, we present Twiti, a system that automatically extracts various forms of malware IOCs from Twitter. Based on the collected IOCs, we conduct the first empirical assessment and thorough analysis of malware IOCs on Twitter. Twiti extracts IOCs from tweets identified as having malware IOC information by leveraging natural language processing and machine learning techniques. With extensive evaluation, we demonstrate that not only can Twiti extract malware IOCs accurately, but also the extracted IOCs are unique and early. By analyzing IOCs in Twiti from various aspects, we find that Twitter captures ongoing malware threats such as Emotet variants and malware distribution sites better than other public threat intelligence (TI) feeds. We also find that only a tiny fraction of IOCs on Twitter come from commercial vendor accounts and individual Twitter users are the main contributors of the early detected or exclusive IOCs, which indicates that Twitter can provide many valuable IOCs uncovered in commercial domain

There is plenty of threat-related information in open data sources. Early identification of emerging security threats from such information is an important part of security for deployed software and systems. While several cybersecurity event detection methods have been proposed to extract security events from unstructured text in open data sources, most of the existing methods focus on detecting events that have a large volume of mentions. On the contrary, to respond faster than attackers, security analysts and IT operators need to be aware of critical security events as early as possible, no matter how many mentions about an event are made. In this paper, we propose a novel event detection system that can quickly identify critical security events, such as new threats and resurgence of an attack or related event, from Twitter regardless of their volume of mentions. Unlike the existing methods, the proposed method triggers events by monitoring new words and re-emerging words, making it possible to narrow down candidate events among several hundreds of events. It then forms events by clustering tweets linked with the trigger words. This approach enables us to detect new and resurgent threats as early as possible. We empirically demonstrate that our system works promisingly over a wide range of threat types.

The remote storage service has been one of the most popular cloud services. However, outsourcing in the remote storage causes a privacy issue such as the exposure of personal data and the leakage of private information. In this paper, we focus on the encrypted keyword search problem, called searchable symmetric encryption in cryptography, to reserve the user privacy and the data confidentiality in cloud storage services. Even though many works have been introduced, they still suffer from limitations in their practical use due to high search costs and huge index size. We present a new keyword search mechanism based on the bitmap index that represents a set of files in the inverted index form. The proposed mechanism has fast search time and small index size compared with the previous works in practical use. We show that it can be directly applied to practical services by testing the known NoSQL database, Couch base.