What's happening?

: A critical remote code execution vulnerability in Remote Desktop Services (RDP). Sandworm (CVE-2014-4114)

: Intentionally exploit known vulnerabilities for educational purposes. Resources like CVE databases (https://cve.mitre.org/) can provide information on known vulnerabilities.

Many hobbyists assume, "I’ll just install the ISO on an air-gapped machine (no internet) and I’ll be fine." But isolation is not a perfect shield. Here is what actually happens:

for Windows 7 in early 2020, almost any original ISO of the OS is considered inherently "vulnerable" to a wide array of known exploits. Why Professionals Use Vulnerable ISOs Exploit Testing

Microsoft provides a way to download Windows 7 directly from their site, but it requires a valid product key for activation.