Security researchers, led by Check Point Research (CPR), have introduced a game-changing approach to combatting .NET malware, leveraging the Harmony library for strategic defense.
Published today, the research delves into the intricate world of code manipulation in malware analysis, emphasizing its critical significance for analysts, researchers, and reverse engineers.
Traditionally, altering code functionality faced challenges in the .NET domain, but Harmony emerges as a beacon of innovation, specializing in real-time patching, replacing, and decorating .NET methods.
The CPR research not only introduces the concept of .NET managed hooking using Harmony but also provides practical insights into its internals with diverse implementation examples, showcasing various types of Harmony patches.
Notably, the library operates exclusively on in-memory code, ensuring modifications do not impact on-disk files, a crucial advantage when dealing with .NET malware shielded by obfuscators.
The research underscores the versatility of Harmony hooking, enabling researchers to modify the functionality of referenced assemblies, particularly those integral to the .NET Runtime, and sheds light on the injection process.
The technical write-up categorizes Harmony patches, including Prefix, Postfix, Transpiler, Finalizer, and Reverse Patch, each playing a distinct role in shaping the behavior of .NET methods.
Highlighting the ease and effectiveness of .NET instrumentation with the Harmony library, this research marks a significant stride in fortifying defenses against sophisticated .NET malware.
