Assemblers And Disassembler Softwares Computer Science Essay

Assemblers And Disassembler Softwares Computer Science Essay A disassembler is a computer program that translates machine language into assembly language the inverse operation to that of an assembler . A disassembler differs from a decompiler which targets a high-level language rather than an assembly language. The output of a disassembler is often formatted for human-readability rather than suitability for input to an assembler, making it principally a reverse-engineering tool. Assembly language source code generally permits the use of constants and programmer comments . These are usually removed from the assembled machine code by the assembler . A disassembler operating on the machine code would produce disassembly lacking these constants and comments. The disassembled output becomes more difficult for a human to interpret than the original annotated source code. Some disassemblers make use of the symbolic debugging information present in object files such as ELF. The Interactive Disassemblerallow the human user to make up mnemonic symbols for values or regions of code in an interactive session: human insight applied to the disassembly process often parallels human creativity in the code writing process. Disassembly is not an exact science: On CISC platforms with variable-width instructions, or in the presence of self-modifying code, it is possible for a single program to have two or more reasonable disassemblies. Determining which instructions would actually be encountered during a run of the program reduces to the proven-unsolvable halting problem. Examples of disassemblers Any interactive debugger will include some way of viewing the disassembly of the program being debugged. Often, the same disassembly tool will be packaged as a standalone disassembler distributed along with the debugger. For example, objdump, part of GNU Binutils, is related to the interactive debugger gdb . The some ofexample of dissembler are IDA ILDASM is a tool contained in the .NET Framework SDK. It can be used to disassemble PE files containing Common Intermediate Language code. OllyDbg is a 32-bit assembler level analysing debugger PVDasm is a Free, Interactive, Multi-CPU disassembler. SIMON a test/ debugger/ animator with integrated dis-assembler for Assembler, COBOL and PL/1 Texe is a Free, 32bit disassembler and windows PE file analyzer. unPIC is a disassembler for PIC microcontrollers Interactive Disassembler Interactive Disassembler The Interactive Disassembler, more commonly known as simply IDA, is a disassembler used for reverse engineering. It supports a variety of executable formats for different processors and operating systems. It also can be used as a debugger for Windows PE, Mac OS XMach-O, and LinuxELF executables. A decompiler plugin for programs compiled with a C/C++compiler is available at extra cost. The latest full version of Ida Pro is commercial.IDA performs much automatic code analysis, using cross-references between code sections knowledge of parameters of API calls, and other information. However the nature of disassembly precludes total accuracy, and a great deal of human intervention is necessarily required. IDA has interactive functionality to aid in improving the disassembly. A typical IDA user will begin with an automatically generated disassembly listing and then convert sections from code to data and viceversa. Scripting IDC scripts make it possible to extend the operation of the disassembler. Some helpful scripts are provided, which can serve as the basis for user written scripts. Most frequently scripts are used for extra modification of the generated code. For example, external symbol tables can be loaded thereby using the function names of the original source code. There are websites devoted to IDA scripts and offer assistance for frequently arising problems. Users have created plugins that allow other common scripting languages to be used instead of, or in addition to, IDC. IdaRUB supports Ruby and IDAPython adds support for Python Supported systems/processors/compilers Operating systems x86WindowsGUI x86 Windows console x86 Linux console x86 Mac OS X ARM Windows CE Executable file formats PE (Windows) ELF (Linux, most *BSD) Mach-O (Mac OS X) Netware .exe OS/2 .exe Geos .exe Dos/Watcom LE executable (without embedded dos extender) raw binary, such as a ROM image Processors Intel 8086 family ARM, including thumb code Motorola 68xxx/h8 ZilogZ80 MOS Technology 6502 Intel i860 DEC Alpha Analog Devices ADSP218x Angstrem KR1878 Atmel AVR series DEC series PDP11 Fujitsu F2MC16L/F2MC16LX Fujitsu FR 32-bit Family Hitachi SH3/SH3B/SH4/SH4B Hitachi H8: h8300/h8300a/h8s300/h8500 Intel 196 series: 80196/80196NP Intel 51 series: 8051/80251b/80251s/80930b/80930s Intel i960 series Intel Itanium (ia64) series Java virtual machine MIPS: mipsb/mipsl/mipsr/mipsrl/r5900b/r5900l Microchip PIC: PIC12Cxx/PIC16Cxx/PIC18Cxx MSIL Mitsubishi 7700 Family: m7700/m7750 Mitsubishi m32/m32rx Mitsubishi m740 Mitsubishi m7900 Motorola DSP 5600x Family: dsp561xx/dsp5663xx/dsp566xx/dsp56k Motorola ColdFire Motorola HCS12 NEC 78K0/78K0S PA-RISC PowerPC SGS-Thomson ST20/ST20c4/ST7 SPARC Family Samsung SAM8 Siemens C166 series TMS320Cxxx series Compiler/libraries (for automatic library function recognition)[3] Borland C++ 5.x for DOS/Windows Borland C++ 3.1 Borland C Builder v4 for DOS/Windows GNU C++ for Cygwin Microsoft C Microsoft QuickC Microsoft Visual C++ Watcom C++ (16/32 bit) for DOS/OS2 ARM C v1.2 GNU C++ for Unix/common SIMON (Batch Interactive test/debug) SIMON (Batch interactive test/debug) was a proprietary test/debugging toolkit for interactively testing Batch programs designed to run on IBMs System 360/370/390 architecture. It operated in two modes, one of which was full instruction set simulator mode and provided Instruction step, conditional Program Breakpoint (Pause) and storage alteration features for Assembler, COBOL and PL/1 programs. High level language (HLL) users were also able to see and modify variables directly at a breakpoint by their symbolic names and set conditional breakpoints by data content. Many of the features were also available in partial monitor mode which relied on deliberately interrupting the program at pre-defined points or when a program check occurred.In this mode, processing was not significantly different from normal processing speed without monitoring. It additionally provided features to prevent application program errors such as Program Check, Wild branch , and Program loop. It was possible to correct many errors and interactively alter the control flow of the executing application program. This permitted more errors to be detected for each compilation which, at the time, were often scheduled batch jobs with printed output, often requiring several hours turnaround before the next test run. Operating Systems Simon could be executed on IBMMVS, MVS/XA, ESA or DOS/VSE operating systems and required IBM 3270 terminals for interaction with the application program. LIDA lida is basically a disassembler and code analysis tool. It uses the bastards libdisasm for single opcode It allows interactive control over the generated deadlisting via commands and builtin tools. features It trace execution flow of binary It work with symbolic names: interactive naming of functions, labels, commenting of code. It scan for known anti-debugging, anti-disassembling techniques It scan for user defined code sequences It integrated patcher It also integrated cryptoanalyzer Many disassemblers out there use the output of objdump à ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬ lida that tries a more serious approach. The several limitations of objdump are broken by using libdisasm and by tracing the execution flow of the program. Further by having the control over the disassembly more features can be included. Everybody who has already worked on some deadlisting will immediate feel a need to work interactive with the code and be able to change it. Therefore lida will have an integrated patcher resolves symbolic names, provides the ability to comment the code, serves efficient browsing methods. The more exotic features of lida should be on the analysis side. The code can be scanned for custom sequences known antidebugging techniques known encryption algorithms also you will be able to directly work with the programs data and for example pass it to several customizable en-/decryption routines. This of course only makes limited sense as it is not a debugger. Tough often I really missed this functionality. Limitations of objdump based disassemblers Usual programs one would like to disassemble are either coded directly in assembly, or use some tricks to avoid beeing disassembled. I will here give a short overview of the most objdump features objdump relies on section headers It is an ELF executable that contains correct section headers. Tough for the OS-loader to run an ELF binary, section headers are not necessary at all. The important thing to get a process loaded into memory are the program headers . So the first common anti disassembling trick is to either drop or manipulate the ELF section headers By doing so, objdump refuses to perform the disassembly: [emailprotected]> file tiny-crackme tiny-crackme: ELF 32-bit LSB executable, Intel 80386, version 1, statically linked, corrupted section header size [emailprotected]> objdump -D tiny-crackme objdump: tiny-crackme: File format not recognized The binary I took as example to verify is yanistos tiny-crackme objdump does not trace the execution flow I By not tracing the execution flow objdump can easily be fooled to just disassemble a few lines and stop there. This means it does not recognize any functions, does not see the code which is stored in data sections. objdump does not trace the execution flow Additionally another common trick is to insert garbage opcodes and overjump them to disalign the disassembly from the execution flow. Example: When an instruction jumps into the middle of the next instruction, objdump does not disassemble from this exact location. It will continue with the next instruction and consequently dissasemble garbage from here on. As a result you will mainly see totally usesless instructions in the whole disassembly. . Implementation Details lida uses libdasm of the bastard for single opcode decoding. It does not use the whole environment including the typhoon database. The main program is coded in perl/TK which uses a C backend for the most timeconsuming parts (disassembly, analysis, scanning for strings). Generally lida is designed to be as fast as possible (the disassembly) by trying not to waste all your RAM 🙂 lida is designed to be also efficient in usability. Therefore all important functions are accessible via single keystrokes, or short commands. This means no clicking around is necessary, you can enter your tasks directly into the commandline. The disassembling engine The disassembling is done in currently 4 (or 6) passes, default is all 6: 1st pass is the main control flow disassembly Here the disassembly is started from the executables entrypoint, and recursively disassembles the binary by following each branch, and stepping into each sub- routine. This leads in also disassembling code blocks in data sections, if existent :), so the disassembly is not limited to a .text section. Also, if indirect jumps/calls are used, the final destination is looked up in the binaries data of course 2nd pass for glibc binaries: A heuristic scan scans for the main() function and starts pass1 there (so also re- cursive disassembling) 3rd pass all other code sections This pass repeats pass1 for all found executable sections, and starts at section start. If the binary does not contain section headers, the disassembly starts at the first loaded executable address. 4th pass functions This pass scans for typical function prologues and starts pass1 at each found address. This is for discovering code regions which are not explicitly called, and where their entrypoints are evaluated at runtime. 5th pass disassembling caves All passes build up a map of the binary. If until now there are code regions which were not yet disassembled, they can be now. 6th pass remainders If pass 5 was executed, and there are still caves, they are displayed as DB xx, Definitely for pass 4 and 5 there are enhancements to come, as well as for the recursive disassembly function itself. Also to mention whenever a jump into the middle of a previous instruction is beeing found, currently those addresses are beeing marked. To follow is a representation of instructions within instructions (compare 3.1), as of course by intelligent placing of opcodes both instructions can be valid and used during the execution flow. Signature Scanning Basically it is done by a signature scanning. I quote it because it is not a simple pattern matching. For understanding that, one needs a little understanding of typical hash-encryption algorythms. Lets take for example a MD5 hash. How can we find the code that does an MD5 hash? On a very high level generating a hash is usually done in 3 steps: the init function, the update function and the finalize function. The init function usually sets up an array of some numeric values, which are then modified in a loop using the input data (plain data) during the algorythm, until the hash is calculated. The finalize function creates the representation in a common format (easily spoken; it pads the digest and is appending the size). Hoewever, it does not matter to know actually how the algorythm works to find it 🙂 Due to the common fact, that the initialization functions use fixed numeric initialization values, which are the same in every implementation, as they are part of the algorythm these are the values we are searching for. For MD5 those are: 0x67452301 0xefcdab89 0x98badcfe 0x10325476 So to find an MD5 implementation, it is necessary to scan for those dword values, of course they can appear in any order (strange enough nearly always they are used in the listed order above). Now as those dwords can exist also in just any binary by accident (oltough seldom) some smarter scanning is done: the values need to appear in a limited size of a code block. The values can be in any order, and also some fuzzyness has been added to scan for a little bit altered init values. Heuristic Scanning Heuristic scanning is not yet implemented. It is intended to find custom crypto code. Basically it is beeing looked for a sequence of suspicious opcode sequences, which look like an encryption routine. OllyDbg is an x86debugger that emphasizes binary code analysis, which is useful when source code is not available. It traces registers, recognizes procedures, API calls, switches, tables, constants and strings, as well as locates routines from object files and libraries. According to the programs help file, version 1.10 is the final 1.x release. Version 2.0 is in development and is being written from the ground up. The software is free of cost, but the shareware license requires users to register with the author. The current version of OllyDbg cannot disassemble binaries compiled for 64-bit processors.

Comparing the Messages of Animal Dreams and The Bean Trees Essay

Political and Social Messages of Animal Dreams and The Bean Trees       Perhaps The Poisonwood Bible is Barbara Kingsolver's best work. It was while reading this book (which centers around The Congo and what the western world has done to this country) that I began to make the connection that all of Kingsolver's books contain a political and social message. She uses her stance as an author to illuminate her readers to situations and issues that she feels are important. Kingsolver's voice can be heard in Animal Dreams when the main character, Codi talks about what happened to her sister, Hallie in Nicaragua, and how unaware Americans were to what was happening in that country. "It made the news in Tucson, at least for a day. You just forgot. That's the great American disease, we forget. We watch the disasters parade by on TV, and every time we say: 'Forget it. This is someone else's problem" (Animal Dreams 316).    The Bean Trees touches on the plight of refugees, both in the real life struggle of a Guatemalan couple living illegally in the US, as well as her main character that in a way is a refugee herself, although only from Kentucky. In Animal Dreams, Kingsolver looks at the people living in Nicaragua and how the US government was/is involved. While the characters and personal stories are fictionalized, the situation seems taken from real life headlines. Kingsolver also touches on environmental issues in Animal Dreams, through the people of the fictional town of Grace, Arizona's struggle against an all consuming mines attempt to poison their water and crops.    For this paper I decided to focus on Barbara Kingsolver's first two novels, The Bean Trees and Animal Dreams. The first topic that ... ...html>.   Duval, Alex. "Shafted: How Phelps Dodge Strips Miners Of Their Rights." Tucson Weekly 19 March 1998. 25 March 1998 <http://www.weeklywire.com/tw/03-19-98/Curr3.html>.   Kingsolver, Barbara. Animal Dreams. New York: HarperCollins, 1990.   ___. The Bean Trees. New York: HarperCollins, 1988.   ___. High Tide in Tucson: Essays From Now or Never.New York: HarperCollins, 1995.   Perry, Donna. Backtalk: Women Writers Speak Out. New Brunswick: Rutgers University Press, 1993.   Schutz, Jorian Polis. "The Impact of the Sandinistas on Nicaragua." Jorian Polis Shutz, 1998. <http://www.jorian.com/san.html>.   Smiley, Jane. "In One Small Town, the Weight of the World." New York Times on the Web. 2 September 1990. 18 October 1998. <http://www.nytimes.com/books/98/10/18/specials/kingsolver-animal.html>.    Comparing the Messages of Animal Dreams and The Bean Trees Essay Political and Social Messages of Animal Dreams and The Bean Trees       Perhaps The Poisonwood Bible is Barbara Kingsolver's best work. It was while reading this book (which centers around The Congo and what the western world has done to this country) that I began to make the connection that all of Kingsolver's books contain a political and social message. She uses her stance as an author to illuminate her readers to situations and issues that she feels are important. Kingsolver's voice can be heard in Animal Dreams when the main character, Codi talks about what happened to her sister, Hallie in Nicaragua, and how unaware Americans were to what was happening in that country. "It made the news in Tucson, at least for a day. You just forgot. That's the great American disease, we forget. We watch the disasters parade by on TV, and every time we say: 'Forget it. This is someone else's problem" (Animal Dreams 316).    The Bean Trees touches on the plight of refugees, both in the real life struggle of a Guatemalan couple living illegally in the US, as well as her main character that in a way is a refugee herself, although only from Kentucky. In Animal Dreams, Kingsolver looks at the people living in Nicaragua and how the US government was/is involved. While the characters and personal stories are fictionalized, the situation seems taken from real life headlines. Kingsolver also touches on environmental issues in Animal Dreams, through the people of the fictional town of Grace, Arizona's struggle against an all consuming mines attempt to poison their water and crops.    For this paper I decided to focus on Barbara Kingsolver's first two novels, The Bean Trees and Animal Dreams. The first topic that ... ...html>.   Duval, Alex. "Shafted: How Phelps Dodge Strips Miners Of Their Rights." Tucson Weekly 19 March 1998. 25 March 1998 <http://www.weeklywire.com/tw/03-19-98/Curr3.html>.   Kingsolver, Barbara. Animal Dreams. New York: HarperCollins, 1990.   ___. The Bean Trees. New York: HarperCollins, 1988.   ___. High Tide in Tucson: Essays From Now or Never.New York: HarperCollins, 1995.   Perry, Donna. Backtalk: Women Writers Speak Out. New Brunswick: Rutgers University Press, 1993.   Schutz, Jorian Polis. "The Impact of the Sandinistas on Nicaragua." Jorian Polis Shutz, 1998. <http://www.jorian.com/san.html>.   Smiley, Jane. "In One Small Town, the Weight of the World." New York Times on the Web. 2 September 1990. 18 October 1998. <http://www.nytimes.com/books/98/10/18/specials/kingsolver-animal.html>.   

Bullying in Primary and Secondary Schools

â€Å"Bullying. This means threatening, harassing, persecuting or insulting others. Especially those who are weaker. It is a daily terror for many children, possibly your child without knowing it. And schools, some more than others are becoming infested with bullies taking advantage of smaller or timid ones. Is your child being bullied at school? This statement made by Professor Ramesh Deosaran is taken from one of his articles (Bullying, The Silent Terror, dated October 17, 2010) which has brought the problem of bullies and bullying within the school system of Trinidad and Tobago into the public domain.Professor Deosaran is an internationally renowned scholar in criminology and social sciences; he has been recently conferred with the title Professor Emeritus at the University of the West Indies, St. Augustine Campus in Trinidad and Tobago. Today I would like to present some facts on â€Å"Bullying in Primary and Secondary Schools†. However due to time constraints, I will foc us on three major aspects in hopes that I may raise your awareness on the severity of the issue. What is bullying?It can be defined as persistent aggressive behavior by one pupil towards another, intended to cause the victim to suffer. It can range from verbal to physical and even indirect. (Chris Kyriacou, â€Å"Helping Troubled Pupils†). The incidence of it in primary and secondary schools in Trinidad and Tobago is quite difficult to estimate since a small proportion of cases are reported to teachers and administrators. These reports are often ignored or some corrective action is taken such as summoning of parents, suspension or even counseling by professionals. Why Do Some People Become Bullies?Most times, they are average students who come from households where discipline is excessive or inconsistent, where family relationships show little warmth and to act aggressively towards others, including adults is the norm. This is possibly because they are not listened to or valu ed by their family. To compensate for this lack of value at home, the bully finds it in other places such as school, in inappropriate or unhealthy ways. Others might be victims themselves, not only of being bullied but because of these personal problems in the home or even parental bereavement.Many times, a bully does not feel that they can find any other means of fitting in, so they turn to being powerful in a way that they feel brings them respect. They feel that being feared is the way to gain friends and surround themselves with people who look up to them. â€Å"Psychologists used to believe that bullies have low self-esteem and put down other people to feel better about themselves. While many bullies are themselves being bullied at home or in school, new research shows that they actually have excellent self-esteem.They usually have a sense of entitlement and superiority over others and lack compassion, impulse control and social skills. (St Clair, 2011). What Is The Impact Of Bullying On Victimized Students? According to a report done by the Global School Based Student Health Survey (GSHS) in 2007 on selected schools in Trinidad and Tobago, â€Å"victims of bullying have increased stress and a reduced ability to concentrate and are at increased risk for substance abuse, aggressive behavior and suicide attempts.† Victims develop mental health problems, become truants or school refusers, perform less well at school academically than they otherwise would have done, especially those who are subjected to frequent and prolonged bullying. They are likely to have lower levels of self-esteem and they appear to have difficulty making friends. This is because they are labeled as â€Å"different† by the bully and peer pressure stops other students from standing up for them. In addition, the high level of depression for victims stems directly from the act itself.(Roland, 2002). Sometimes victims are encouraged to believe that this something which all st udents must endure as a part of growing up. By accepting this mentality, the student’s emotional health and well-being are put at stake and the learning process undermined. The student may even develop a decrease ability to devise coping strategies. It may mean that these students may never learn to cope as adults and they cannot form long term relationships. What Is Being Done By the Authorities In Trinidad and Tobago?Thus far, the Ministry of Education has placed Human and Family Life Education (HFLE) on secondary schools’ curriculum and it is taught in most schools. â€Å"The Government of Trinidad and Tobago is looking at the preventative aspect and at early detection and treatment of the problem. † This statement made by The Minister of Education, Tim Gopeesingh, on the 14th of April, 2012. He added that there were preventative measures implemented such as â€Å"The Leader in Me† programme for preschool right up to secondary schools.Student Guidance Support Units in schools are being expanded and a hotline is being set up for children who are bullied. Furthermore, the Chief Education Officer has sent a curricular to all schools asking principals to allow students to have one class per week (Form Teacher Period) in which they can tell of the difficulties they are experiencing. Challenges and Evaluation of Sources In gathering the information required for my research, I had encountered certain challenges along the way. I had an over-abundance of information.It was extremely time consuming to summarize and pick out the most valid and relevant points. However trusted sites were used such as ttparliament. org, bullyonline. org, stopbullying. gov and youthoria. org. These sites were reliable as they were maintained by their organizations consistently and the articles were up to date. A book entitled â€Å"Helping Troubled Pupils† by Chris Kyriacou was very useful as it contained an entire chapter on the topic of bullying from which I was able to extract several valid points.I considered the book a valid source since it was written by a psychologist specifically to help teachers and parents. Conclusion Recent increases in the incidence of bullying among youths in Trinidad and Tobago have led to growing concern about this serious issue. The Government is currently tackling the issue by implementation of preventative measures and by education of students and the public. Although bullying in primary and secondary in schools may never be eradicated,

How to Get Into Business School

Not everyone gets accepted into their business school of choice. This is especially true of individuals who apply to top business schools. A top business school, sometimes known as a first tier business school, is a school that is highly ranked among other business schools by multiple organizations. On average, fewer than 12 out of every 100 people who apply to a top business school will receive an acceptance letter. The higher ranked a school is, the more selective they tend to be. For example, Harvard Business School, one of the best-ranked schools in the world, rejects thousands of MBA applicants each year. These facts are not meant to discourage you from applying to business school - you cant be  accepted if you dont apply - but they are meant to help you understand that getting into business school is a challenge. You will have to work hard at it and take the  time to prepare your MBA application and improve your candidacy if you want to increase your chances of getting accepted to your school of choice.    In this article, were going to explore two things that you should be doing right now to prepare for the MBA application process as well as common mistakes that you should avoid in order to increase your chances of success. Find a Business School That Fits You There are many components that go into a business school application, but one of the most important things to focus on right from the start is targeting the right schools. Fit is essential if you want to get accepted into an MBA program. You can have outstanding test scores, glowing recommendation letters, and fantastic essays, but if you arent a good fit for the school you are applying to, you will most likely get turned away in favor of a candidate who is a good fit. Many MBA candidates start their search for the right school by looking at  business school rankings. Although rankings are important - they give you a great picture of the schools reputation - they are not the only thing that matters. To find a school that is a fit for your academic ability and career goals, you need to look beyond rankings and into the schools culture, people, and location. Culture: Business school culture is an important factor because it dictates the environment. Some schools have a close-knit, collaborative culture; others have a more competitive culture that encourages self-sufficiency. You need to ask yourself what kind of student you are and what type of environment you are most likely to thrive in.People: You will be spending a lot of time with the people in your incoming class. Would you prefer a large class or small intimate classes? And what about the professors? Do you want to be taught by people who value research or do you want professors who focus on application?Location: Cost of living, weather, proximity to family, networking opportunities, and internship availability are all affected by the location of your business school. A big city will likely come with more opportunities, but it may also be more expensive to study in this type of environment. A small college town or a rural setting could be more affordable, but may provide fewer opp ortunities for networking and culture. Find Out What the School Is Looking For Every business school will tell you that they work hard to build a diverse class and that they dont have a typical student. While that may be true on some level, every business school has an archetypical student. This student is almost always professional, business-minded, passionate, and willing to work hard to achieve their goals. Beyond that, every school is different, so you need to understand what the school is looking for to ensure that 1.) the school is a good fit for you 2.) you can deliver an application that fits their needs. You can get to know the school by visiting the campus, speaking to current students, reaching out to the alumni network, attending MBA fairs, and conducting good old-fashioned research. Seek out interviews that have been conducted with the schools admission officers, peruse the schools blog and other publications, and read everything you can about the school. Eventually, a picture will begin to form that shows you what the school is looking for. For example, the school may be looking for students who have leadership potential, strong technical abilities, the desire to collaborate, and an interest in social responsibility and global business. When you find that the school is looking for something you have, you need to let that piece of you shine in your  resume, essays, and recommendations. Avoid Common Mistakes Nobody is perfect. Mistakes happen. But you don’t want to make a silly mistake that makes you look bad to an admissions committee. There are a few common mistakes that applicants make time and time again. You might scoff at some of these and think that you would never be careless enough to make  that mistake, but keep in mind that the applicants who made these mistakes probably thought the same thing at one time. Recycling essays. If you are applying to multiple schools (and you should), it is important to write an original essay for each application. Dont recycle your MBA application essays. Admissions committees can spot this trick from a mile away. And if you do disregard this advice and decide to recycle the essay, remember to change the name of the school in the essay. Believe it or not, applicants make this mistake every year! If you submit an essay to Columbia explaining why you want to go to Harvard, the admissions committee will peg you as someone who doesn’t pay attention to detail - and theyll be right to do so.Not Sharing. Admissions committees look through a lot of essays every year. This can be extremely boring - especially when the essays are generic. The point of the essay is to help admissions committees get to know you, so let your personality shine. Demonstrate who you are. It will help your application.Skipping Optional Opportunities. Some business schools have opti onal essays or optional interviews. Dont make the mistake of skipping these optional opportunities. Show the school that you want to get in. Do the essay. Do the interview. And take advantage of every other opportunity that comes your way.Not Retaking the GMAT. GMAT scores are important to your application. If your scores arent falling in the range for the previous years entering class, you should retake the GMAT to get a better score. The Graduate Management Admission Council reports that approximately one-third of the people who take the GMAT take it at least twice, if not more. Most of these people increase their score the second time around. Be one of those people.