How does this technique relate to other exploitation methods for loading DLLs or assemblies, such as Java JNI or .NET Assembly.Load?

This method is conceptually similar to other code-loading techniques like [Analysis of Exploitation Techniques for Loading .NET Assemblies from Memory (Assembly.Load)](/news/analysis-of-exploitation-techniques-for-loading-net-assemblies-from-memory-assembly-load) and [Java Exploitation Techniques – Loading DLL via JNI](/news/java-exploitation-techniques-loading-dll-via-jni), where an application's API is abused to load and execute arbitrary code. The key difference is that RegisterXLL() relies on Microsoft Excel's legitimate functionality, making it stealthy for Office environments.