During the information gathering phase of a penetration test, you are tasked with using strategic search engine analysis to uncover potential leads about an organization's internet-facing infrastructure. Which of the following search queries could reveal the existence of sensitive documents that the company did not intend to make public?
site:example.com filetype:pdf confidential
link:example.com -site:example.com
example.com:2087 -site:example.com
intitle:index.of server at example.com