DPAPI.py usage with PVK is broken

[Nimretz]

Description

DPAPI.py's "get_domain_backup_key" ignores PVK file input as argument. All DPAPI modules (mobaxterm , putty , etc) are using that function which basically tries to export the domain backup key instead of using the provided PVK.

Type of change

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• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Deprecation of feature or functionality
• This change requires a documentation update
• This requires a third party update (such as Impacket, Dploot, lsassy, etc)
• This PR was created with the assistance of AI (list what type of assistance, tool(s)/model(s) in the description)

Setup guide for the review

when running "nxc smb target -u user -p pass --pvk caps_dpapi_backupkey.pvk -M mobaxterm -M putty"
you expect the modules to use the provided PVK. Instead - the "get_domain_backup_key" function tries to export the domain backup key from the DC. I modified the function to first check for PVK argument before trying to export the domain backup key.

Screenshots (if appropriate):

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If appropriate, include before and after screenshot(s) to show which results are to be expected.

Checklist:

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• I have ran Ruff against my changes (poetry: poetry run ruff check ., use --fix to automatically fix what it can)
• I have added or updated the tests/e2e_commands.txt file if necessary (new modules or features are required to be added to the e2e tests)
• If reliant on changes of third party dependencies, such as Impacket, dploot, lsassy, etc, I have linked the relevant PRs in those projects
• I have linked relevant sources that describes the added technique (blog posts, documentation, etc)
• I have performed a self-review of my own code (not an AI review)
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (PR here: https://github.com/Pennyw0rth/NetExec-Wiki)