During an internal network penetration test, a tester recovers the NTLM password hash tor a user known to have full administrator privileges on a number of target systems Efforts to crack the hash…

Windows 7 is fully end-of-life and while technically vulnerable to pass-the-hash, it is less likely to represent a realistic active target in modern environments compared to Windows 8.1.

Windows Server 2016 supports Credential Guard and enhanced NTLM protections that isolate credentials in a virtualized environment, making pass-the-hash attacks significantly more difficult.

Windows 8.1 is vulnerable to pass-the-hash (PtH) attacks, which allow an attacker to authenticate to remote systems using only the captured NTLM hash without needing the plaintext password. Unlike Windows Server 2016, which supports Credential Guard and other credential isolation features that significantly hinder PtH attacks, Windows 8.1 lacks these advanced protections, making it the best target for exploiting the recovered hash.

Windows 8 reached end-of-life in January 2016 and is an older, less likely target compared to Windows 8.1, which had a longer support lifecycle and broader deployment.