Reference: https://phoenixnap.com/kb/nmap-scan-open-ports

When a penetration tester captures screen images that include hashes from a domain controller, obscuring parts of these images before saving is crucial to maintain the confidentiality of sensitive data. Hashes can be considered sensitive information as they represent a form of digital identity for users within an organization.
Revealing these hashes in full could lead to unauthorized access if the hashes were to be cracked or otherwise misused by malicious actors. By partially obscuring the images, the penetration tester ensures that the data remains confidential and reduces the risk of compromising user accounts and the integrity of the organization's security posture.

https://nmap.org/book/scan-methods-ack-scan.html

Reference: https://shahmeeramir.com/penetration-testing-of-an-ftp-server-19afe538be4b

https://kalilinuxtutorials.com/foca-metadata-hidden-documents/
FOCA (Fingerprinting Organizations with Collected Archives) is a tool that is used to find hidden information in documents available on the web. It can be used to extract metadata from documents such as PDF, Microsoft Office, OpenOffice, and others. The metadata can include information such as the author, creation date, and software used to create the document. FOCA can also extract information from the document's properties such as the title, keywords, and comments. This tool can also identify specific keywords and patterns in the document and can be useful in identifying sensitive information that may have been inadvertently left in the document.