Techniques here do not include obfuscation like false branches, spaghetti code etc. Techniques currently covered by detection plugins will have an additional information. Meanwhile such kind of protection tricks are often used, several approaches work against such kind of protection. But, also global strategies defined on the program to. Detecting debugging this article describes anti debugger techniques for x86linux though some of these techniques are not x86 specific. This effectively makes the names of the functions unavailable when debugging, which leaves it up to the debugger to properly name the functions. Pdf files have evolved to run specific actions and allow for the execution of javascript. This can be useful to the development of viruses and also to those implementing software protection. Antiforensics af tools and techniques frustrate cfts by erasing or altering information. Antidebugging techniques some antidebugging techniques are described in the next sections. We wont consider different theories of software protection, only practical examples. The best way to be prepared for an attack is to know where one could come from. Rootkits allow attackers to hide their tools from other programs running on the same computer. Antidebugging features can be preventive or reactive.
Introduction into windows antidebugging codeproject. Antidebugging techniques are ways for a program to detect if it runs under control of a debugger. 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. Peb ntglobalflag ntglobalflag is a field of peb at offset 0x68 1. 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. Very often we encounter pdf files that cannot be loaded or are not displayed correctly. Acrobat also has a spiffy pdf syntax check in its advancedpreflight profiles. 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. 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. So, when you attach a debugger to a program, it generates an interrupt interrupt. The android application package file, apk file, can be easily decompiled using android reverse engineering tools. Hooking and other techniques for hiding and protection.
The main goal of various antireverse engineering techniques is simply to complicate the process as much as possible. Theyre invaluable when youre trying to be compliant. 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. Anti debugging tls callback tls thread local storage a separate storage area for each thread. The promise of these techniques is that they will prevent attackers from using their favorite tools. In most cases, the anti debugging process will slow down the process of reverse engineering, but will not prevent it. Its also got checks for various pdf standards pdfx, pdfa1 a and b, etc, accessibility, and so forth. More than 40 million people use github to discover, fork, and contribute to over 100 million projects. The int 2d antidebugging technique is essentially an application of os finger printing, i. Decloaking serverside malware via cubist program analysis acsac 19, december 9, 2019, san juan, pr, usa. Antidebugging techniques malware analysis seminar meeting 3 cody cutler, anton burtsev. 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.
Antidebugging detection and obufuscation techniques that involved the use of win32 api functions. These tricks can simply detect the presence of the debugger, disable the debugger, escape from the control of the debugger, or even exploit a. And when youre trying to debug a broken pdf, acrobat being helpful is the last thing you need. Beginners guide to basic linux anti anti debugging techniques. Decloaking serverside malware via cubist program analysis. They are used by commercial executable protectors, packers and malicious software, to prevent or slowdown the process of reverseengineering. Antidebugging tls callback tls thread local storage a separate storage area for each thread. It covers the very basic anti debugging techniques as introduced by silvio cesares paper 1 back in 1999. As is the case with the generalclass of adversarial. There are some antiantidebugging techniques proposed. Most protection schemes include various antidebugger techniques. So, here i decided to transcribe that into a series of posts, and to start it off. We can use didier stevens pdf tools to help us analyze pdfs.
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. Schallner beginners guide to basic linux anti anti. This paper categorizes traditional af techniques such as encrypted file. 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 article presents popular anti debugging techniques, starting from the simplest, and notes how to bypass them. Linux antidebugging techniques fooling the debugger. 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. 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. That said, malware themselves use very similar techniques as antivirus to detect debugging, virtual machines, and other common analyst tools and techniques. Perhaps the simplest anti debugging method is calling the isdebuggerpresent function. Antidebugging scheme for protecting mobile apps on. This section discusses standard debugging techniques that you can apply across different technologies and different types of code.
This article presents popular antidebugging techniques, starting from the simplest, and notes how to bypass them. This simple tool was written in assembler x86 win32 api and the antidebugging method are. They are used by commercial executable protectors, packers and malicious software, to prevent or slowdown the process of. A good antidebugging scheme should defend against both types of debugging. Android antireversing defenses mobile security testing. This toolset runs using python, so we will again need that installed. Windows antidebug reference this paper classifies and presents several antidebugging techniques used on windows ntbased operating systems. If binary files conceal or modify themself using antidebugging techniques, analyzing these binary files becomes harder. 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.
Scientific but not academical overview of malware anti. 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. For a pretty complete reference on antidebugging techniques under windows, consult peter ferries paper. 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. Antidebugging and antivm techniques and antiemulation. So we decided to analyze it and on the way also describe some interesting antidebugging techniques that are. As i see those techniques are still used in applications and crackmes, this paper should show a how easy and. It can be used to execute instructions before the entry point where the debugger starts, so debugger doesnt see these instructions. But in recent years there has been an emergence of af that directly target cfts. The technique easiest to bypass is symbol elimination where we have to delete all the symbols presented in the executable. The reality is that they are either too simple and thus easy.
Antidebugging techniques were designed to protect the intellectual property of compiled code. Mindfulness for relaxation and anxiety management the techniques youwere just using are called mindfulness skills. 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. As the name implies, preventive anti debugging prevents the debugger from attaching in the first place. As the name implies, preventive antidebugging prevents the debugger from attaching in the first place. Programs can have event handlers that look for this particular interrupt and exit automatically when it is found. 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. 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. These techniques can be easily evaded by a debugger, by purposely masking the return result or the kernel data structure of the operating system. I am thinking about techniques such as the ptrace test at the beginning of a program or at various points of its execution, the insertion of fake breakpoints eg int30xcc x86 opcode or time checks. That is techniques to either fool, stop, or modify the process of debugging the target program. Thus, general apps can be easily transformed into malicious application through reverse engineering and analysis.
Antidebugging is the implementation of one or more techniques within computer code that hinders attempts at reverse engineering or debugging a target process. May 2006 abstract anti debugging techniques are a common method for protecting software applications. Beginners guide to basic linux anti anti debugging techniques schallner, m. Relaxation skills for anxiety university of michigan. 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. 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. 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. Computer forensic tools cfts allow investigators to recover deleted files, reconstruct an intruders activities, and gain intelligence about a computers user. A good anti debugging scheme should defend against both types of debugging. Towards an understanding of antivirtualization and anti. Anti debugging features can be preventive or reactive. They can be as simple as isdebuggerpresent or complex as attempting to detect or crash a particular version of softice. A cyberkillchain based taxonomy of cryptoransomware.
It is actively used by recognized publishers in copyprotection schemas, but is also used by malware to complicate its detection and elimination. 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. For pdf analysis, what we can do is extract event information and analyze what the javascript will do. Weve seen a few techniques to harden the reverse engineering process. Software license key system with time trial options. This paper is an introduction for anti anti debugging techniques on the linux os. Recent studies 7, 18 show that antivirtualization and antidebugging techniques have become the most popular methods of evading malware analysis. Debugger is a tool or a program that inspects other programs interactions with cpu while they are being executed and loaded in memory. 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.
204 116 886 386 673 54 165 271 1217 151 1397 1191 1054 910 1234 455 275 1396 1029 617 811 646 1233 1558 907 1243 1352 144 396 797 1286 75 978 860