Tag: “web”


Identifying Extension-based Ad Injection via Fine-grained Web Content Provenance

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Extensions provide useful additional functionality for web browsers, but are also an increasingly popular vector for attacks. Due to the high degree of privilege extensions can hold, extensions have been abused to inject advertisements into web pages that divert revenue from content publishers and potentially expose users to malware. Users are often unaware of such practices, believing the modifications to the page originate from publishers. Additionally, automated identification of unwanted third-party modifications is fundamentally difficult, as users are the ultimate arbiters of whether content is undesired in the absence of outright malice.

To resolve this dilemma, we present a fine-grained approach to tracking the provenance of web content at the level of individual DOM elements. In conjunction with visual indicators, provenance information can be used to reliably determine the source of content modifications, distinguishing publisher content from content that originates from third parties such as extensions. We describe a prototype implementation of the approach called OriginTracer for Chromium, and evaluate its effectiveness, usability, and performance overhead through a user study and automated experiments. The results demonstrate a statistically significant improvement in the ability of users to identify unwanted third-party content such as injected ads with modest performance overhead.

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Excision and CuriousDroid at FC 2016

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The lab has two papers at Financial Crypto this year: Excision, our system for in-browser detection of malware using inclusion sequence analysis, and CuriousDroid, our system for intelligently exercising mobile applications to improve dynamic analysis.

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Presenting CrossFire at Black Hat Asia 2016

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Ahmet and I will be presenting CrossFire at Black Hat Asia in Singapore in March. CrossFire is a new attack against Firefox that leverages extension reuse to bypass the extension vetting process, which is the main line of defense against malicious Firefox extensions.

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An Empirical Analysis of Input Validation Mechanisms in Web Applications and Languages

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Web applications have become an integral part of the daily lives of millions of users. Unfortunately, web applications are also frequently targeted by attackers, and attacks such as XSS and SQL injection are still common.

In this paper, we present an empirical study of more than 7000 input validation vulnerabilities with the aim of gaining deeper insights into how these common web vulnerabilities can be prevented. In particular, we focus on the relationship between the specific programming language used to develop web applications and the vulnerabilities that are commonly reported. Our findings suggest that most SQL injection and a significant number of XSS vulnerabilities can be prevented using straight-forward validation mechanisms based on common data types. We elaborate on these common data types, and discuss how support could be provided in web application frameworks.

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