Obfuscating code for memory protection

Abstract

Cheating through memory manipulation is common in video games due to tools that allow locating and modifying game variables. This thesis examined how values are stored in memory and whether obfuscation methods can prevent entry level memory attacks. The objective of this thesis was to evaluate the effectiveness of obfuscation using a test application created in Unity game engine. The study was conducted by creating an application containing a modifiable integer value and analyzing how memory scanning tools such as Cheat Engine attempt to find and modify this value. Projected value, reversed value and XOR based obfuscation methods were tested with the application. Each method modifies the protected value before storing it in memory in such a way that the actual value is never directly stored. Memory scans were then performed using several initial and subsequent scans with different scan options to assess whether the protected value could be realistically located and modified. The results show that without obfuscation, the protected value can be reliably found and modified using exact value scans. All obfuscation methods successfully prevented memory scans from locating and manipulating the protected value. All methods were readable with minimal impact to performance. The study concludes that obfuscation provides an effective method to protect against entry level memory manipulation attacks while being a practical option to many developers.