Security researchers have not too long ago revealed new insights into countering .NET malware utilizing the modern Harmony library.
The analysis, revealed as we speak, explores the significance of code manipulation in malware evaluation, highlighting its essential position for researchers, analysts, and reverse engineers.
Traditionally, code performance is altered via debugging, Dynamic Binary Instrumentation (DBI), or hooking frameworks. However, when coping with purposes working on the .NET platform, these strategies have confirmed to be much less efficient for managed code. This presents challenges for researchers, however Check Point Research (CPR) is now selling the Harmony library as an answer.
Harmony is an open-source library that makes a speciality of patching, changing, and adorning .NET strategies in real-time, overcoming the restrictions related to altering managed code.
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The CPR analysis piece launched the idea of .NET managed hooking utilizing the Harmony library, delving into its internals and offering sensible implementation examples. It additionally showcased various kinds of Harmony patches.
The Harmony library operates solely on in-memory code, guaranteeing that modifications don’t affect recordsdata on disk. This is very helpful when coping with .NET malware protected by obfuscators, as disk-based deobfuscation dangers altering the unique construction and inflicting performance loss.
The analysis additionally emphasised the flexibility of Harmony hooking, permitting researchers to change the performance of all referenced assemblies, significantly these integral to the .NET Runtime. It additionally outlined the bootstrapping and injection course of, showcasing how Harmony could be injected into .NET processes, both via loaders or injectors.
Furthermore, the analysis categorized numerous kinds of Harmony patches, equivalent to Prefix, Postfix, Transpiler, Finalizer, and Reverse Patch, every serving a particular objective in modifying the conduct of .NET strategies.
“These examples reveal how highly effective .NET hooking could be and, extra importantly, how simple and easy it’s to implement .NET instrumentation as soon as we use the Harmony library,” reads the technical write-up.