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Software cracking (known as "breaking" mostly in the 1980s[1]) is an act of removing copy protection from a software.[2] Copy protection can be removed by applying a specific crack. A crack would refer to any tool to enable breaking into a computer network or a software application.[3] Examples of cracks are: applying a patch or by creating reverse-engineered serial number generators known as keygens, thus bypassing software registration and payments or converting a trial/demo version of the software into fully-functioning software without paying for it.[4] Software cracking contributes to the rise of online piracy where pirated software is distributed to end-users[2] through filesharing sites like BitTorrent, One click hosting (OCH), or via Usenet downloads, or by downloading bundles of the original software with cracks or keygens.[4]

Some of these tools are called keygen, patch, loader, or no-disc crack. A keygen is a handmade product serial number generator that often offers the ability to generate working serial numbers in your own name. A patch is a small computer program that modifies the machine code of another program. This has the advantage for a cracker to not include a large executable in a release when only a few bytes are changed.[5] A loader modifies the startup flow of a program and does not remove the protection but circumvents it.[6][7] A well-known example of a loader is a trainer used to cheat in games.[8] Fairlight pointed out in one of their .nfo files that these type of cracks are not allowed for warez scene game releases.[9][6][10] A nukewar has shown that the protection may not kick in at any point for it to be a valid crack.[11]

Software cracking is closely related to reverse engineering because the process of attacking a copy protection technology, is similar to the process of reverse engineering.[12] The distribution of cracked copies is illegal in most countries. There have been lawsuits over cracking software.[13] It might be legal to use cracked software in certain circumstances.[14] Educational resources for reverse engineering and software cracking are, however, legal and available in the form of Crackme programs.


Softwares are inherently expensive to produce but cheap to duplicate and distribute. Therefore, software producers generally tried to implement some form of copy protection before releasing it to the market. In 1984, Laind Huntsman, the head of software development for Formaster, a software protection company, commented that "no protection system has remained uncracked by enterprising programmers for more than a few months".[2] In 2001, Dan S. Wallach, a professor from Rice University, argued that "those determined to bypass copy-protection have always found ways to do so – and always will".[15]

Most of the early software crackers were computer hobbyists who often formed groups that competed against each other in the cracking and spreading of software. Breaking a new copy protection scheme as quickly as possible was often regarded as an opportunity to demonstrate one's technical superiority rather than a possibility of money-making. Software crackers usually did not benefit materially from their actions and their motivation was the challenge itself of removing the protection.[2] Some low skilled hobbyists would take already cracked software and edit various unencrypted strings of text in it to change messages a game would tell a game player, often something considered vulgar. Uploading the altered copies on file sharing networks provided a source of laughs for adult users. The cracker groups of the 1980s started to advertise themselves and their skills by attaching animated screens known as crack intros in the software programs they cracked and released.[16] Once the technical competition had expanded from the challenges of cracking to the challenges of creating visually stunning intros, the foundations for a new subculture known as demoscene were established. Demoscene started to separate itself from the illegal "warez scene" during the 1990s and is now regarded as a completely different subculture. Many software crackers have later grown into extremely capable software reverse engineers; the deep knowledge of assembly required in order to crack protections enables them to reverse engineer drivers in order to port them from binary-only drivers for Windows to drivers with source code for Linux and other free operating systems. Also because music and game intro was such an integral part of gaming the music format and graphics became very popular when hardware became affordable for the home user.

With the rise of the Internet, software crackers developed secretive online organizations. In the latter half of the nineties, one of the most respected sources of information about "software protection reversing" was Fravia's website.

In 2017, a group of software crackers started a project to preserve Apple II softwares by removing the inherent Apple II copy protection.[17]


The High Cracking University (+HCU) was founded by Old Red Cracker (+ORC), considered a genius of reverse engineering and a legendary figure in RCE, to advance research into Reverse Code Engineering (RCE). He had also taught and authored many papers on the subject, and his texts are considered classics in the field and are mandatory reading for students of RCE.[18]

The addition of the "+" sign in front of the nickname of a reverser signified membership in the +HCU. Amongst the students of +HCU were the top of the elite Windows reversers worldwide.[18] +HCU published a new reverse engineering problem annually and a small number of respondents with the best replies qualified for an undergraduate position at the university.[18]

+Fravia was a professor at +HCU. Fravia's website was known as "+Fravia's Pages of Reverse Engineering" and he used it to challenge programmers as well as the wider society to "reverse engineer" the "brainwashing of a corrupt and rampant materialism". In its heyday, his website received millions of visitors per year and its influence was "widespread".[18] On his site, +Fravia also maintained a database of the tutorials generated by +HCU students for posterity.[19]

Nowadays most of the graduates of +HCU have migrated to Linux and few have remained as Windows reversers. The information at the university has been rediscovered by a new generation of researchers and practitioners of RCE who have started new research projects in the field.[18]


The most common software crack is the modification of an application's binary to cause or prevent a specific key branch in the program's execution. This is accomplished by reverse engineering the compiled program code using a debugger such as SoftICE,[20] OllyDbg, GDB, or MacsBug until the software cracker reaches the subroutine that contains the primary method of protecting the software (or by disassembling an executable file with a program such as IDA).[21] The binary is then modified using the debugger or a hex editor such as HIEW[22] or monitor in a manner that replaces a prior branching opcode with its complement or a NOP opcode so the key branch will either always execute a specific subroutine or skip over it. Almost all common software cracks are a variation of this type. Proprietary software developers are constantly developing techniques such as code obfuscation, encryption, and self-modifying code to make this modification increasingly difficult.[23] Even with these measures being taken, developers struggle to combat software cracking. This is because it is very common for a professional to publicly release a simple cracked EXE or Retrium Installer for public download, eliminating the need for inexperienced users to crack the software themselves.

A specific example of this technique is a crack that removes the expiration period from a time-limited trial of an application. These cracks are usually programs that alter the program executable and sometimes the .dll or .so linked to the application and the process of altering the original binary files is called patching.[12] Similar cracks are available for software that requires a hardware dongle. A company can also break the copy protection of programs that they have legally purchased but that are licensed to particular hardware, so that there is no risk of downtime due to hardware failure (and, of course, no need to restrict oneself to running the software on bought hardware only).

Another method is the use of special software such as CloneCD to scan for the use of a commercial copy protection application. After discovering the software used to protect the application, another tool may be used to remove the copy protection from the software on the CD or DVD. This may enable another program such as Alcohol 120%, CloneDVD, Game Jackal, or Daemon Tools to copy the protected software to a user's hard disk. Popular commercial copy protection applications which may be scanned for include SafeDisc and StarForce.[24]

In other cases, it might be possible to decompile a program in order to get access to the original source code or code on a level higher than machine code. This is often possible with scripting languages and languages utilizing JIT compilation. An example is cracking (or debugging) on the .NET platform where one might consider manipulating CIL to achieve one's needs. Java's bytecode also works in a similar fashion in which there is an intermediate language before the program is compiled to run on the platform dependent machine code.[25]

Advanced reverse engineering for protections such as SecuROM, SafeDisc, StarForce, or Denuvo requires a cracker, or many crackers to spend much more time studying the protection, eventually finding every flaw within the protection code, and then coding their own tools to "unwrap" the protection automatically from executable (.EXE) and library (.DLL) files.

There are a number of sites on the Internet that let users download cracks produced by warez groups for popular games and applications (although at the danger of acquiring malicious software that is sometimes distributed via such sites).[26] Although these cracks are used by legal buyers of software, they can also be used by people who have downloaded or otherwise obtained unauthorized copies (often through P2P networks).

Software piracy

Software cracking led to the distribution of pirated software around the world (software piracy). It was estimated that the United States lost US$ 2.3 billion in business application software in 1996. Software piracy rates were especially prevalent in African, Asian, East European, and Latin American countries. In certain countries such as Indonesia, Indonesia, Pakistan, Kuwait, China, and El Salvador,[27] 90% of the software used was pirated.[28]

See also


  1. ^ Kevelson, Morton (October 1985). "Isepic". Ahoy!. pp. 71–73. Retrieved June 27, 2014. The origin of the term probably lies in the activity burglars in the still of the night.
  2. ^ a b c d "What Motivates Software Crackers?" (PDF). Sigi Goode and Sam Cruise, Australian National University, Journal of Business Ethics (2006). Archived (PDF) from the original on October 21, 2022. Retrieved April 30, 2022.
  3. ^ Tulloch, Mitch (2003). Microsoft Encyclopedia of Security (PDF). Redmond, Washington: Microsoft Press. p. 68. ISBN 0735618771. Archived from the original (PDF) on August 10, 2014. Retrieved July 20, 2014.
  4. ^ a b Kammerstetter, Markus; Platzer, Christian; Wondracek, Gilbert (October 16, 2012). "Vanity, cracks and malware: insights into the anti-copy protection ecosystem". Proceedings of the 2012 ACM conference on Computer and communications security. Raleigh North Carolina USA: ACM: 809–820. doi:10.1145/2382196.2382282. ISBN 978-1-4503-1651-4.
  5. ^ Craig, Paul; Ron, Mark (April 2005). "Chapter 4: Crackers". In Burnett, Mark (ed.). Software Piracy Exposed - Secrets from the Dark Side Revealed. Publisher: Andrew Williams, Page Layout and Art: Patricia Lupien, Acquisitions Editor: Jaime Quigley, Copy Editor: Judy Eby, Technical Editor: Mark Burnett, Indexer: Nara Wood, Cover Designer: Michael Kavish. United States of America: Syngress Publishing. pp. 75–76. doi:10.1016/B978-193226698-6/50029-5. ISBN 1-932266-98-4.
  6. ^ a b FLT (January 22, 2013). "The_Sims_3_70s_80s_and_90s_Stuff-FLT". Archived from the original on September 14, 2014. Retrieved September 13, 2014. This can be the only reason you have come to the conclusion that a modified startup flow is the same like the imitated behavior of a protection, like an EMU does it.
  7. ^ Shub-Nigurrath [ARTeam]; ThunderPwr [ARTeam] (January 2006). "Cracking with Loaders: Theory, General Approach, and a Framework". CodeBreakers Magazine. Universitas-Virtualis Research Project. 1 (1). A loader is a program able to load in memory and running another program.
  8. ^ Nigurrath, Shub (May 2006). "Guide on how to play with processes memory, writing loaders, and Oraculumns". CodeBreakers Magazine. Universitas-Virtualis Research Project. 1 (2).
  9. ^ FLT (September 29, 2013). "Test_Drive_Ferrari_Legends_PROPER-FLT". Archived from the original on September 14, 2014. Retrieved September 13, 2014. Test.Drive.Ferrari.Racing.Legends-SKIDROW was released with a "Loader" and not a cracked exe. This is why you see the original exe renamed to "TDFerrari_o.exe". As this is not allowed and in this case considerably slows down the game with Xlive messages while starting and playing the game, you can see why we have included a proper cracked.
  10. ^ SKIDROW (January 21, 2013). "Test.Drive.Ferrari.Racing.Legends.Read.Nfo-SKIDROW". Archived from the original on September 14, 2014. Retrieved September 13, 2014. Yes our "method" is a loader and our competitors have used the same method for "cracking" xlive games like this.
  11. ^ "Batman.Arkham.City-FiGHTCLUB nukewar". December 2, 2011. Archived from the original on September 13, 2014. UNNUKED: game.plays.full no.issues no.single.byte.patch.used [ZoNeNET]
  12. ^ a b Eilam, Eldad (2005). Reversing : secrets of reverse engineering. Elliot J. Chikofsky. Indianapolis, IN: Wiley. ISBN 0-7645-9768-X. OCLC 80242141.
  13. ^ Cheng, Jacqui (September 27, 2006). "Microsoft files lawsuit over DRM crack". Ars Technica. Archived from the original on July 15, 2014. Retrieved June 15, 2017.
  14. ^ Fravia (November 1998). "Is reverse engineering legal?". Archived from the original on March 5, 2022.
  15. ^ Wallach, D.S. (October 2001). "Copy protection technology is doomed". Computer. 34 (10): 48–49. doi:10.1109/2.955098. Archived from the original on January 21, 2022. Retrieved March 10, 2023.
  16. ^ Reunanen, Markku; Wasiak, Patryk; Botz, Daniel (March 26, 2015). "Crack Intros: Piracy, Creativity and Communication". International Journal of Communication. 9: 20. ISSN 1932-8036. Archived from the original on June 17, 2022. Retrieved June 17, 2022.
  17. ^ Pearson, Jordan (July 24, 2017). "Programmers Are Racing to Save Apple II Software Before It Goes Extinct". Motherboard. Archived from the original on September 27, 2017. Retrieved January 27, 2018.
  18. ^ a b c d e Cyrus Peikari; Anton Chuvakin (January 12, 2004). Security Warrior. "O'Reilly Media, Inc.". p. 31. ISBN 978-0-596-55239-8.
  19. ^ Vianello, Francesco. "Academy Home Page". Fravia's archive pages of reverse engineering. Archived from the original on September 26, 2022. Retrieved May 17, 2022.
  20. ^ Ankit, Jain; Jason, Kuo; Jordan, Soet; Brian, Tse (April 2007). "Software Cracking (April 2007)" (PDF). The University of British Columbia - Electrical and Computer Engineering. Archived (PDF) from the original on March 19, 2018. Retrieved January 27, 2018. ((cite journal)): Cite journal requires |journal= (help)
  21. ^ Cerven, Pavol (2002). Crackproof Your Software: Protect Your Software Against Crackers. ISBN 1-886411-79-4.
  22. ^ "Protecting Software Codes By Guards" (PDF). Hoi Chang, Mikhail J. Atallah, CERIAS, Purdue University (2001). Archived (PDF) from the original on March 10, 2023. Retrieved June 6, 2022.
  23. ^ Reverse engineering code with IDA Pro. Justin Ferguson, Dan Kaminsky. Burlington, MA: Syngress Pub. 2008. ISBN 978-0-08-055879-0. OCLC 272383172. Archived from the original on March 10, 2023. Retrieved June 8, 2022.((cite book)): CS1 maint: others (link)
  24. ^ "Gamecopyworld Howto". Archived from the original on June 5, 2008. Retrieved June 11, 2008.
  25. ^ "A Survey of Reverse Engineering Tools for the 32-Bit Microsoft Windows Environment" (PDF). RAYMOND J. CANZANESE, JR., MATTHEW OYER, SPIROS MANCORIDIS, MOSHE KAM, Drexel University, USA. Archived (PDF) from the original on March 25, 2022. Retrieved June 7, 2022.
  26. ^ McCandless, David (April 1, 1997). "Warez Wars". Wired. ISSN 1059-1028. Archived from the original on September 16, 2021. Retrieved February 4, 2020.
  27. ^ Gopal, Ram D.; Sanders, G. Lawrence (September 2000). "Global software piracy: you can't get blood out of a turnip". Communications of the ACM. 43 (9): 82–89. doi:10.1145/348941.349002. ISSN 0001-0782.
  28. ^ Gopal, Ram D.; Sanders, G. Lawrence (1998). "International Software Piracy: Analysis of Key Issues and Impacts". Information Systems Research. 9 (4): 380–397. doi:10.1287/isre.9.4.380. ISSN 1047-7047. JSTOR 23011033.