PDF文件中隐藏数据的利用与清理
Exploitation and Sanitization of Hidden Data in PDF Files
摘要：
组织发布和共享越来越多的电子文档，如PDF文件。不幸的是，大多数组织都没有意识到这些文档可能会泄露敏感信息，如作者姓名、信息系统和体系结构的详细信息。所有这些信息都可以很容易地被攻击者利用来跟踪并随后攻击组织。在本文中，我们分析了隐藏的数据中发现的PDF文件发布的组织。我们收集了来自47个国家的75个安全机构发布的39664个PDF文件。我们已经能够衡量这些PDF文件中暴露的信息的质量和数量。它可以有效地用于找到组织中的薄弱环节：运行过时软件的员工。我们还测量了安全机构对PDF文件清理的采用情况。我们发现只有7个安全机构在发布之前对他们的PDF文件进行了一些清理。不幸的是，我们仍然能够在这些经过消毒的PDF文件中找到65%的敏感信息。一些机构正在使用弱的清理技术：它需要从文件中删除所有隐藏的敏感信息，而不仅仅是删除表面上的数据。安全机构需要改变他们的清理方法。
英文摘要：
Organizations publish and share more and more electronic documents like PDF files. Unfortunately, most organizations are unaware that these documents can compromise sensitive information like authors names, details on the information system and architecture. All these information can be exploited easily by attackers to footprint and later attack an organization. In this paper, we analyze hidden data found in the PDF files published by an organization. We gathered a corpus of 39664 PDF files published by 75 security agencies from 47 countries. We have been able to measure the quality and quantity of information exposed in these PDF files. It can be effectively used to find weak links in an organization: employees who are running outdated software. We have also measured the adoption of PDF files sanitization by security agencies. We identified only 7 security agencies which sanitize few of their PDF files before publishing. Unfortunately, we were still able to find sensitive information within 65% of these sanitized PDF files. Some agencies are using weak sanitization techniques: it requires to remove all the hidden sensitive information from the file and not just to remove the data at the surface. Security agencies need to change their sanitization methods.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
