Refactor ransomware extension classes and add generic detection

[bartblaze]

Refactored ransomware extension classes and added a generic extension detection class. Should resolve #512

[gemini-code-assist]

Summary of Changes

Hello @bartblaze, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request refactors the ransomware extension detection logic by separating specific, known ransomware family extensions from more generic ones. This change improves the modularity and maintainability of the detection signatures, allowing for more precise identification of known threats while also providing a dedicated mechanism for catching broader, less specific ransomware activity. The refactoring also addresses issue #512.

Highlights

• Class Renaming: The primary ransomware extension detection class has been renamed from "RansomwareExtensions" to "RansomwareExtensionsKnown" for improved clarity and distinction.
• Generic Extension Extraction: Generic ransomware file extension patterns (e.g., ".encrypt", ".locked", ".encrypted") have been removed from the "RansomwareExtensionsKnown" class.
• New Generic Detection Class: A new signature class, "RansomwareExtensionsGeneric", has been introduced to specifically detect common, generic ransomware file extensions.
• Threat Intelligence Mapping: The new generic detection class includes MITRE ATT&CK (TTPs) and MBC (micro-behaviors) references for enhanced threat intelligence mapping.

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[gemini-code-assist]

Code Review

This pull request refactors the ransomware extension detection by separating known, family-specific extensions from generic ones into a new RansomwareExtensionsGeneric class. This is a good architectural improvement. My review focuses on the newly introduced RansomwareExtensionsGeneric class, where I've found a significant correctness issue in the regular expression patterns that could lead to false positives, and a couple of opportunities to improve code readability and robustness. I've provided code suggestions to address these points.

[doomedraven]

Thank you