So, when you attach a debugger to a program, it generates an interrupt interrupt. Thus, general apps can be easily transformed into malicious application through reverse engineering and analysis. Antidebugging scheme for protecting mobile apps on. If binary files conceal or modify themself using antidebugging techniques, analyzing these binary files becomes harder. Theyre invaluable when youre trying to be compliant. Beginners guide to basic linux anti anti debugging techniques. For a pretty complete reference on antidebugging techniques under windows, consult peter ferries paper. The reality is that they are either too simple and thus easy. This section discusses standard debugging techniques that you can apply across different technologies and different types of code. Schallner beginners guide to basic linux anti anti. But, also global strategies defined on the program to. Anti debugging techniques are meant to ensure that a program is not running under a debugger, and in the case that it is, to change its behavior correspondingly. More than 40 million people use github to discover, fork, and contribute to over 100 million projects.
They can be as simple as isdebuggerpresent or complex as attempting to detect or crash a particular version of softice. Acrobat also has a spiffy pdf syntax check in its advancedpreflight profiles. Most protection schemes include various antidebugger techniques. Very often we encounter pdf files that cannot be loaded or are not displayed correctly.
Decloaking serverside malware via cubist program analysis acsac 19, december 9, 2019, san juan, pr, usa. We wont consider different theories of software protection, only practical examples. Windows antidebug reference this paper classifies and presents several antidebugging techniques used on windows ntbased operating systems. Its been quite a while i analyzed malware last time, so i decided to refresh my knowledge and write a short post on common x86 malware antidebugging techniques. Antidebugging techniques are ways for a program to detect if it runs under control of a debugger. A good antidebugging scheme should defend against both types of debugging. Or they can be loaded with adobe reader which is very forgiving when it comes to pdf errors but they cannot be loaded with another tool and the customer asks why. Perhaps the simplest anti debugging method is calling the isdebuggerpresent function. As i see those techniques are still used in applications and crackmes, this paper should show a how easy and. Antidebugging techniques now in order to frustrate the malware analyst, malware can be detected in the presence of debuggers and show up in unexpected events. Anti debugging tls callback tls thread local storage a separate storage area for each thread. As the name implies, preventive antidebugging prevents the debugger from attaching in the first place. Its also got checks for various pdf standards pdfx, pdfa1 a and b, etc, accessibility, and so forth. For example, an antidebugging program can call system library functions such as isdebuggerpresent, or to examine the data structure of thread information block tibteb of the operating system.
B were first spotted in the wild in the second half of 2010, but customers are still calling us due to difficulties in removing it even in the presence of antivirus software. Pdf files have evolved to run specific actions and allow for the execution of javascript. This effectively makes the names of the functions unavailable when debugging, which leaves it up to the debugger to properly name the functions. In most cases, the anti debugging process will slow down the process of reverse engineering, but will not prevent it. These tricks can simply detect the presence of the debugger, disable the debugger, escape from the control of the debugger, or even exploit a. As i see those techniques are still used in applications and crackmes, this paper should show a how easy and outdated those techniques are, and b explain why ptrace and objdump are not always your friends, but finally there is always a way. A good anti debugging scheme should defend against both types of debugging. Its been quite a while i analyzed malware last time, so i decided to refresh my knowledge and write a short post on common x86 malware anti debugging techniques. Peb ntglobalflag ntglobalflag is a field of peb at offset 0x68 1.
This paper is an introduction for anti anti debugging techniques on the linux os. Android antireversing defenses mobile security testing. Anti debugging features can be preventive or reactive. Rootkits allow attackers to hide their tools from other programs running on the same computer. This simple tool was written in assembler x86 win32 api and the antidebugging method are. The main goal of various antireverse engineering techniques is simply to complicate the process as much as possible. A cyberkillchain based taxonomy of cryptoransomware. We can use didier stevens pdf tools to help us analyze pdfs. It can be used to execute instructions before the entry point where the debugger starts, so debugger doesnt see these instructions. May 2006 abstract anti debugging techniques are a common method for protecting software applications. Pdf anticopy is a windows pdf security utility that prevents pdf text from being copied and converted to editable formats. May 2006 abstract antidebugging techniques are a common method for protecting software applications. This can be useful to the development of viruses and also to those implementing software protection. Programs can have event handlers that look for this particular interrupt and exit automatically when it is found.
It is actively used by recognized publishers in copyprotection schemas, but is also used by malware to complicate its detection and elimination. That said, malware themselves use very similar techniques as antivirus to detect debugging, virtual machines, and other common analyst tools and techniques. They are used by commercial executable protectors, packers and malicious software, to prevent or slowdown the process of reverseengineering. That is techniques to either fool, stop, or modify the process of debugging the target program. Techniques currently covered by detection plugins will have an additional information. Antidebugging features can be preventive or reactive. For pdf analysis, what we can do is extract event information and analyze what the javascript will do. Implementing anti detection techniques should be specific for each malware type, all the methods explained in this paper will also work for all kind of malware but this paper mainly focuses on stager meterpreter payloads because meterpreter is capable of all the things that all other malware does, getting a meterpreter session on remote machine. Microsoft windows pe file format, x86 assembly language, disassembly and debugging with ida, packer analysis, malware antidebugging techniques, windows api nonwindows executable malware pdf file format, analysing pdf files, android malware, document malware. Antiforensics af tools and techniques frustrate cfts by erasing or altering information.
In order to detect the presence of a debugger, malware can either read some values or it can use api present to detect if the malware is being debugged or not. So, here i decided to transcribe that into a series of posts, and to start it off. Antidebugging techniques malware analysis seminar meeting 3 cody cutler, anton burtsev. Techniques here do not include obfuscation like false branches, spaghetti code etc. Mindfulness for relaxation and anxiety management the techniques youwere just using are called mindfulness skills. From the point of view of a program analysis researcher, it could be a very exciting problem to automatically generate such antidebugging techniques, given the sourcebinary code. Beginners guide to basic linux anti anti debugging techniques schallner, m. As the name implies, preventive anti debugging prevents the debugger from attaching in the first place. It covers the very basic anti debugging techniques as introduced by silvio cesares paper 1 back in 1999. The int 2d antidebugging technique is essentially an application of os finger printing, i. Introduction into windows antidebugging codeproject. Decloaking serverside malware via cubist program analysis.
And when youre trying to debug a broken pdf, acrobat being helpful is the last thing you need. Antidebugging 9 unfortunately, most professionals use plugins as strongod, phantom, hideod and ollyadvanced for evading antidebugging techniques, but miss the chance of learning interesting techniques used by malwares, which most time can be modified for bypassing famous debugger as ollydbg and immunity. This toolset runs using python, so we will again need that installed. Antidebugging detection and obufuscation techniques that involved the use of win32 api functions. So, a while ago for my at the time local def con chapter, dc480, i did a quick presentation on some antidebugging mechanisms and techniques that one can use to better secure their totally legitimate software against debugging and general reverse engineering. Relaxation skills for anxiety university of michigan. Debugger is a tool or a program that inspects other programs interactions with cpu while they are being executed and loaded in memory. This article presents popular anti debugging techniques, starting from the simplest, and notes how to bypass them. Antidebugging tls callback tls thread local storage a separate storage area for each thread. As is the case with the generalclass of adversarial. Towards an understanding of antivirtualization and anti.
The technique easiest to bypass is symbol elimination where we have to delete all the symbols presented in the executable. Processed pdf files could be opened and viewed by pdf readers, but copying and converting the content on the anticopy pages will not work even the cracker uses the pdf unlocking or restriction removing programs. At the end of the day, antianything is always checking for some values being stored at. For a complete solution which defeats most antidebugging techniques in an automated fashion, have a look at the source code of ida stealth, a plugin for the popular interactive disassembler. Linux antidebugging techniques fooling the debugger. Antidebugging techniques were designed to protect the intellectual property of compiled code.
This paper categorizes traditional af techniques such as encrypted file. The best way to be prepared for an attack is to know where one could come from. So we decided to analyze it and on the way also describe some interesting antidebugging techniques that are. This article presents popular antidebugging techniques, starting from the simplest, and notes how to bypass them. As a result, anti debugging tricks are probably the most common feature of code intended to interfere with reverseengineering and anti disassembly constructs being the next most common. Weve seen a few techniques to harden the reverse engineering process. These are techniques that originate in buddhist meditation practices, butthey havebeen studied and used moreand moreby psychologists and physicians in the last 20 years or so to help people regulate their emotionsand calm their minds. Software license key system with time trial options.
Behavior graph simulations behavior and apis antivirus detection initial sample dropped files unpacked pe files domains yara overview initial sample pcap network traffic dropped files memory dumps unpacked pes joe sandbox. Detecting debugging this article describes anti debugger techniques for x86linux though some of these techniques are not x86 specific. The android application package file, apk file, can be easily decompiled using android reverse engineering tools. Scientific but not academical overview of malware anti. I am trying to scan all possible techniques to disrupt the usage of a debugger on a unix platform ie posix and a bit more. Antidebugging techniques some antidebugging techniques are described in the next sections. Computer forensic tools cfts allow investigators to recover deleted files, reconstruct an intruders activities, and gain intelligence about a computers user. Recent studies 7, 18 show that antivirtualization and antidebugging techniques have become the most popular methods of evading malware analysis. Hooking and other techniques for hiding and protection. But in recent years there has been an emergence of af that directly target cfts. Antidebugging is the implementation of one or more techniques within computer code that hinders attempts at reverse engineering or debugging a target process. Antidebugging and antivm techniques and antiemulation. The promise of these techniques is that they will prevent attackers from using their favorite tools. They are used by commercial executable protectors, packers and malicious software, to prevent or slowdown the process of.
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