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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"><HTML><HEAD> <TITLE>Maximum Security -- Ch 3 -- Hackers and Crackers</TITLE></HEAD><BODY TEXT="#000000" BGCOLOR="#FFFFFF"><CENTER><H1><IMG SRC="../button/samsnet.gif" WIDTH="171" HEIGHT="66" ALIGN="BOTTOM" BORDER="0"><BR><FONT COLOR="#000077">Maximum Security: </FONT></H1></CENTER><CENTER><H2><FONT COLOR="#000077">A Hacker's Guide to Protecting Your Internet Site and Network</FONT></H2></CENTER><CENTER><P><A HREF="../ch02/ch02.htm"><IMG SRC="../button/previous.gif" WIDTH="128" HEIGHT="28"ALIGN="BOTTOM" ALT="Previous chapter" BORDER="0"></A><A HREF="../ch04/ch04.htm"><IMGSRC="../button/next.gif" WIDTH="128" HEIGHT="28" ALIGN="BOTTOM" ALT="Next chapter"BORDER="0"></A><A HREF="../index.htm"><IMG SRC="../button/contents.gif" WIDTH="128"HEIGHT="28" ALIGN="BOTTOM" ALT="Contents" BORDER="0"></A> <HR></CENTER><CENTER><H1><FONT COLOR="#000077">3</FONT></H1></CENTER><CENTER><H1><FONT COLOR="#000077">Hackers and Crackers</FONT></H1></CENTER><P>The focus of this chapter is on hackers, crackers, and the differences betweenthem.<H2><FONT COLOR="#000077"><B>What Is the Difference Between a Hacker and a Cracker?</B></FONT></H2><P>There have been many articles written (particularly on the Internet) about thedifference between hackers and crackers. In them, authors often attempt to correctpublic misconceptions. This chapter is my contribution in clarifying the issue.</P><P>For many years, the American media has erroneously applied the word <I>hacker</I>when it really means <I>cracker</I>. So the American public now believe that a hackeris someone who breaks into computer systems. This is untrue and does a disserviceto some of our most talented hackers.</P><P>There are some traditional tests to determine the difference between hackers andcrackers. I provide these in order of their acceptance. First, I want to offer thegeneral definitions of each term. This will provide a basis for the remaining portionof this chapter. Those definitions are as follows:</P><UL> <LI>A <I>hacker</I> is a person intensely interested in the arcane and recondite workings of any computer operating system. Most often, hackers are programmers. As such, hackers obtain advanced knowledge of operating systems and programming languages. They may know of holes within systems and the reasons for such holes. Hackers constantly seek further knowledge, freely share what they have discovered, and never, ever intentionally damage data.<BR> <BR> <LI>A <I>cracker</I> is a person who breaks into or otherwise violates the system integrity of remote machines, with malicious intent. Crackers, having gained unauthorized access, destroy vital data, deny legitimate users service, or basically cause problems for their targets. Crackers can easily be identified because their actions are malicious.</UL><P>These definitions are good and may be used in the general sense. However, thereare other tests. One is the legal test. It is said that by applying legal reasoningto the equation, you can differentiate between hackers (or any other party) and crackers.This test requires no extensive legal training. It is applied simply by inquiringas to <I>mens rea</I>.<H3><FONT COLOR="#000077"><I><B>Mens Rea</B></I></FONT></H3><P><I>Mens rea</I> is a Latin term that refers to the guilty mind. It is used todescribe that mental condition in which criminal intent exists. Applying <I>mensrea</I> to the hacker-cracker equation seems simple enough. If the suspect unwittinglypenetrated a computer system--and did so by methods that any law-abiding citizenwould have employed at the time--there is no <I>mens rea</I> and therefore no crime.However, if the suspect was well aware that a security breach was underway--and heknowingly employed sophisticated methods of implementing that breach--<I>mens rea</I>exists and a crime has been committed. By this measure, at least from a legal pointof view, the former is an unwitting computer user (possibly a hacker) and the lattera cracker. In my opinion, however, this test is too rigid.</P><P>At day's end, hackers and crackers are human beings, creatures too complex tosum up with a single rule. The better way to distinguish these individuals wouldbe to understand their motivations and their ways of life. I want to start with thehacker.</P><P>To understand the mind-set of the hacker, you must first know what they do. Toexplain that, I need to briefly discuss computer languages.<H4><FONT COLOR="#000077"><B>Computer Languages</B></FONT></H4><P>A computer language is any set of libraries or instructions that, when properlyarranged and compiled, can constitute a functional computer program. The buildingblocks of any given computer language never fundamentally change. Therefore, eachprogrammer walks to his or her keyboard and begins with the same basic tools as hisor her fellows. Examples of such tools include</P><UL> <LI>Language libraries--These are pre-fabbed functions that perform common actions that are usually included in any computer program (routines that read a directory, for example). They are provided to the programmer so that he or she can concentrate on other, less generic aspects of a computer program.<BR> <BR> <LI>Compilers--These are software programs that convert the programmer's written code to an executable format, suitable for running on this or that platform.</UL><P>The programmer is given nothing more than languages (except a few manuals thatdescribe how these tools are to be used). It is therefore up to the programmer whathappens next. The programmer programs to either learn or create, whether for profitor not. This is a useful function, not a wasteful one. Throughout these processesof learning and creating, the programmer applies one magical element that is absentwithin both the language libraries and the compiler: imagination. That is the programmer'sexistence in a nutshell.</P><P>Modern hackers, however, reach deeper still. They probe the system, often at amicrocosmic level, finding holes in software and snags in logic. They write programsto check the integrity of other programs. Thus, when a hacker creates a program thatcan automatically check the security structure of a remote machine, this representsa desire to better what now exists. It is creation and improvement through the processof analysis.</P><P>In contrast, crackers rarely write their own programs. Instead, they beg, borrow,or steal tools from others. They use these tools not to improve Internet security,but to subvert it. They have technique, perhaps, but seldom possess programming skillsor imagination. They learn all the holes and may be exceptionally talented at practicingtheir dark arts, but they remain limited. A true cracker creates nothing and destroysmuch. His chief pleasure comes from disrupting or otherwise adversely effecting thecomputer services of others.</P><P>This is the division of hacker and cracker. Both are powerful forces on the Internet,and both will remain permanently. And, as you have probably guessed by now, someindividuals may qualify for both categories. The very existence of such individualsassists in further clouding the division between these two odd groups of people.Now, I know that real hackers reading this are saying to themselves "There isno such thing as this creature you are talking about. One is either a hacker or acracker and there's no more to it."<H4><FONT COLOR="#000077"><B>Randal Schwartz</B></FONT></H4><P>If you had asked me five years ago, I would have agreed. However, today, it justisn't true. A good case in point is Randal Schwartz, whom some of you know from hisweighty contributions to the programming communities, particularly his discourseson the Practical Extraction and Report Language (Perl). With the exception of Perl'screator, Larry Wall, no one has done more to educate the general public on the Perlprogramming language. Schwartz has therefore had a most beneficial influence on theInternet in general. Additionally, Schwartz has held positions in consulting at theUniversity of Buffalo, Silicon Graphics (SGI), Motorola Corporation, and Air Net.He is an extremely gifted programmer.<BLOCKQUOTE> <P><HR><FONT COLOR="#000077"><B>NOTE:</B></FONT><B> </B>Schwartz has authored or co-authored quite a few books about Perl, including <I>Learning Perl</I>, usually called "The Llama Book," published by O'Reilly & Associates (ISBN 1-56592-042-2). <HR></BLOCKQUOTE><P>His contributions notwithstanding, Schwartz remains on the thin line between hackerand cracker. In fall 1993 (and for some time prior), Schwartz was employed as a consultantat Intel in Oregon. In his capacity as a system administrator, Schwartz was authorizedto implement certain security procedures. As he would later explain on the witnessstand, testifying on his own behalf:<DL> <DD>Part of my work involved being sure that the computer systems were secure, to pay attention to information assets, because the entire company resides--the product of the company is what's sitting on those disks. That's what the people are producing. They are sitting at their work stations. So protecting that information was my job, to look at the situation, see what needed to be fixed, what needed to be changed, what needed to be installed, what needed to be altered in such a way that the information was protected.</DL><P>The following events transpired:</P><UL> <LI>On October 28, 1993, another system administrator at Intel noticed heavy processes being run from a machine under his control.<BR> <BR> <LI>Upon examination of those processes, the system administrator concluded that the program being run was Crack, a common utility used to crack passwords on UNIX systems. This utility was apparently being applied to network passwords at Intel and at least one other firm.<BR> <BR> <LI>Further examination revealed that the processes were being run by Schwartz or someone using his login and password.<BR> <BR> <LI>The system administrator contacted a superior who confirmed that Schwartz was not authorized to crack the network passwords at Intel.<BR> <BR> <LI>On November 1, 1993, that system administrator provided an affidavit that was sufficient to support a search warrant for Schwartz's home.<BR> <BR> <LI>The search warrant was served and Schwartz was subsequently arrested, charged under an obscure Oregon computer crime statute. The case is bizarre. You have a skilled and renowned programmer charged with maintaining internal security for a large firm. He undertakes procedures to test the security of that network and is ultimately arrested for his efforts. At least, the case initially appears that way. Unfortunately, that is not the end of the story. Schwartz did not have authorization to crack those password files. Moreover, there is some evidence that he violated other network security conventions at Intel.</UL>⌨️ 快捷键说明
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