AppMark: A Picture-Based Watermark for Android Apps

Smartphones have become common tools in people's daily life. Lots of popular applications (e.g., social network applications) have immigrated from traditional computers to smartphones. With the growth of the apps, attacks on these apps are also increasing. One serious attack adds malicious payloads or advertisements to legitimate apps. These modified apps, called repackaged apps, share similar functionalities with the original apps, which makes them easily spread. To mitigate this attack, we embed watermarks into Android apps. Specially, to make the watermarks robust, we embed a new kind of watermarks called picture-based watermarks into Android apps. By making the inherent characteristics of pictures, it is resilient to obfuscation. We implemented a prototype call AppMark. We evaluated its effectiveness and performance overhead. According to the results, the picture-based watermark is both effective and efficient.