Course 33 - Static Analysis for Reverse Engineering | Episode 4: Static Analysis and Software Patching in x64dbg

In this lesson, you’ll learn about: applying static analysis and patching to modify software behavior1. Core ConceptThis episode demonstrates how to use x64dbg with the xAnalyzer plugin to:Analyze program logic without constant executionIdentify and modify key instructionsAlter how a program enforces trial limitations2. Locating Critical LogicSearch for meaningful strings like:"trial period remaining"This helps you:Jump directly to the function responsible for:License checksExpiration logic3. Visualizing Program FlowUse the graph view (CFG) to:Understand decision paths clearlyIdentify key instructions like:JG (Jump if Greater)👉 This instruction acts as:A decision gate between:Trial still validTrial expired4. Understanding the Logic Behind the TrialThe program calculates remaining time using:A fixed value (e.g., 1E in hex = 30 days)It performs:A subtraction between:Current dateAllowed trial duration5. The Patching Idea (High-Level)Instead of changing logic flow, the approach modifies:The data value controlling the limitExample concept:Increasing the maximum allowed durationResults in a longer trial period6. Validation StepAfter modification:Save the updated binaryRun the programConfirm:Trial duration has increasedBehavior matches expectationsKey TakeawaysStatic analysis helps you pinpoint critical logicCFG visualization simplifies complex branching decisionsTrial systems often rely on:Simple arithmetic checksSmall changes in values can significantly affect behaviorAlways verify changes through testingBig PictureThis workflow shows how reverse engineers:Break down program logicIdentify control pointsModify behavior with precisionYou can listen and download our episodes for free on more than 10 different platforms:https://linktr.ee/cybercode_academy