The Research On The Obfuscation Security Of SWF File

SWF is the unique anataiton format file for the design software of Flash. Thesoftware belongs to the Macromedia company.When zoomed in or out,it has nosignificant loss of quality. Also SWF has the characteristics of small size.SWF fileconsists of file header and a series of tags. In order to achieve the better userinteractions with the interface,ActionScriptcode,AS for short, is added. With thedevolpment of the Internet, SWF is widely used in the network and has graduallybecome the mainstream of multimedia.But then, flash security problem is also veryimportant.Currently there are more and more decompilers for SWF,suchusSothink SWFDecompiler. Sothink SWF Decompiler can not only decomplie SWFinto the format offla,but alsotheelememnt ofSWF,such as sound、picture、fonts、script and son on,canbe paresed.Therefore, the safety researchof SWF is of great significance.This paper study the the safety research of SWF with the entry point ofActionScriptlanguage.In this paper, the research process is as follows:First of all,SWF file stucture is analyzed, especially DoABCtag.DoABC tag is the storage ofActionScript Byte Code file(abc file for short) whichis produced by compliming theActionScript script language.Second,we can get a lot of information aboutActionScript script languageby analyzing ActionScript Byte Code.Third,with thetechnology of code obfuscation,we can make ActionScript Byte Code file confusedfor the purpose of SWF safety.Atlast,we will assess SWF with the help ofdecompilationtools.Intheory,the SWF file which is confused can play without anyproblem,just likebefore.Thedecompilation tools also can decompile the SWF file.Butthe ActionScript code of SWF file which is produce by decompilation tools can notbeunderstandedeasily.That is to say,by reducing the readability of the code produced bydecompilation tools,we can achieve the goal of SWF safety.In this paper, finally, the research work is summarized, and further researchdirection is pointed out.