A collaborative framework for generating probabilistic contracts

We propose a collaborative framework for generating probabilistic contracts for Android smartphones aimed at detecting repackaged applications. To this end, a network of users sends to the application server the sequences of actions that represent the usage profile of the application. Then, the application server generates a contract from this set of traces. Contracts are represented through clustered probabilistic automata. At run-time, a monitoring system on the smartphone verifies the compliance of the running application against the contract through the Pearson's Chi Squared test. In the preliminary tests, the proposed framework has been able to detect repackaged applications whose behavior is strongly similar to the original application but hide malware.