44 research outputs found
DBank: Predictive Behavioral Analysis of Recent Android Banking Trojans
Using a novel dataset of Android banking trojans (ABTs), other Android malware, and goodware, we develop the \sf {DBank}DBank system to predict whether a given Android APK is a banking trojan or not. We introduce the novel concept of a Triadic Suspicion Graph (TSG for short) which contains three kinds of nodes: goodware, banking trojans, and API packages. We develop a novel feature space based on two classes of scores derived from TSGs: suspicion scores (SUS) and suspicion ranks (SR) - the latter yields a family of features that generalize PageRank. While TSG features (based on SUS/SR scores) provide very high predictive accuracy on their own in predicting recent (2016-2017) ABTs, we show that the combination of TSG features with previously studied lightweight static and dynamic features in the literature yields the highest accuracy in distinguishing ABTs from goodware, while preserving the same accuracy of prior feature combinations in distinguishing ABTs from other Android malware. In particular, \sf {DBank}DBank's overall accuracy in predicting whether an APK is a banking trojan or not is up to 99.9% AUC with 0.3% false positive rate. Moreover, we have already reported two unlabeled APKs from VirusTotal (which \sf {DBank}DBank has detected as ABTs) to the Google Android Security Team - in one case, we discovered it before any of the 63 anti-virus products on VirusTotal did, and in the other case, we beat 62 of 63 anti-viruses on VirusTotal. This suggests that \sf {DBank}DBank is capable of making new discoveries in the wild before other established vendors. We also show that our novel TSG features have some interesting defensive properties as they are robust to knowledge of the training set by an adversary: even if the adversary uses 90% of our training set and uses the exact TSG features that we use, it is difficult for him to infer \sf {DBank}DBank's predictions on APKs. We additionally identify the features that best separate and characterize ABTs from goodware as well as from other Android malware. Finally, we develop a detailed data-driven analysis of five major recent ABT families: FakeToken, Svpeng, Asacub, BankBot, and Marcher, and identify the features that best separate them from goodware and other-malware
Probabilistic Interval XML EDWARD HUNG Hong Kong Polytechnic University and
Interest in XML databases has been expanding rapidly over the last few years. In this paper, we study the problem of incorporating probabilistic information into XML databases. We propose the Probabilistic Interval XML (PIXML for short) data model in this paper. Using this data model, users can express probabilistic information within XML markups. In addition, we provide two alternative formal model-theoretic semantics for PIXML data. The first semantics is a “global ” semantics which is relatively intuitive, but is not directly amenable to computation. The second semantics is a “local ” semantics which supports efficient computation. We prove several correspondence results between the two semantics. To our knowledge, this is the first formal model theoretic semantics for probabilistic interval XML. We then provide an operational semantics that may be used to comput
Distributed algorithms for dynamic survivability of multiagent systems
Though multiagent systems (MASs) are being increasingly used, few methods exist to ensure survivability of MASs. All existing methods suffer from two flaws. First, a centralized survivability algorithm (CSA) ensures survivability of the MAS – unfortunately, if the node on which the CSA exists goes down, the survivability of the MAS is questionable. Second, no mechanism exists to change how the MAS is deployed when external factors trigger a re-evaluation of the survivability of the MAS. In this paper, we present three algorithms to address these two important problems. Our algorithms can be built on top of any CSA. Our algorithms are completely distributed and can handle external triggers to compute a new deployment. We report on experiments assessing the efficiency of these algorithms
Utilizing volatile external information during planning
There are many practical planning situations in which planners may need information from external sources during the planning process. We describe the following:
. Wrappers that may be placed around conventional (isolated) planners. The wrapper replaces some of the planner's memory accesses with queries to external information sources. When appropriate, the wrapper will automatically backtrack the planner to a previous point in its operation.
. Query-management strategies for wrappers. These dictate when to issue queries, and when/how to backtrack the planner.
. Mathematical analysis and experimental tests. Our results show conditions under which different query management strategies are preferable, and demonstrate that certain kinds of planning paradigms are more suited than others for planning with volatile information
