The first blog : The first blog

What Is a Password Cracker?

2008-10-20T18:17:26Z

The term password cracker can be misinterpreted, so I want to define it here. A password

cracker is any vcp braindumps
program that can decrypt passwords or otherwise disable password

protection. A password cracker need not decrypt anything. In fact, most of them don't.

Real encrypted passwords, as you will shortly learn, cannot be reverse-decrypted.

A more precise way to explain this is as follows: encrypted passwords cannot be

decrypted. Most modern, technical encryption processes are now one-way (that is, there

is no process to be executed in reverse that will reveal the password in plain text).

Instead, simulation tools are used, utilizing the same algorithm as the original password

program. Through a comparative analysis, these tools try to match encrypted versions of

the password to the original (this is explained a bit later in this chapter). Many so-called

password crackers are nothing butTestking vcp-310
brute-force engines--programs that try word after

word, often at high speeds. These rely on the theory that eventually, you will encounter

the right word or phrase. This theory has been proven to be sound, primarily due to the

factor of human laziness. Humans simply do not take care to create strong passwords.

However, this is not always the user's fault:

Users are rarely, if ever, educated as to what are wise choices for passwords. If a password is in

the dictionary, it is extremely vulnerable to being cracked, and users are simply not coached as to

"safe" choices for passwords. Of those users who are so educated, many think that simply because

their password is not in /usr/dict/words, it is safe from detection. Many users also say that

because they do not have private files online, Pass4sure vcp-310
they are not concerned with the security of their

account, little realizing that by providing an entry point to the system they allow damage to be

wrought on their entire system by a malicious cracker.1

The Target Machine As Another Platform

2008-10-20T18:16:29Z

Scanning platforms other than vcp test questions
UNIX might or might not be of significant value. At least,

this is true with respect to deployment of TCP port scanners. This is because the majority

of non-UNIX platforms that support TCP/IP support only portions of TCP/IP. In fact,

some of those TCP/IP implementations are quite stripped down. Frankly, several TCP/IP

implementations have support for a Web server only. (Equally, even those that have

support for more might not evidence additional ports or services because these have been

disabled.)

This is the main reason that certain platforms, like the Macintosh platform, have thus far

seen fewer intrusions than UNIX-based vcp test exam
operating systems. The fewer services you

actually run, the less likely it is that a hole will be found. That is common sense.

Equally, many platforms other than UNIX do support extensive TCP/IP. AS/400 is one

such platform. Microsoft Windows NT (with Internet Information Server) is another.

Certainly, any system that runs any form of TCP/IP could potentially support a wide

range of protocols. Novell NetWare, for example, has long had support for TCP/IP.

It boils down to this: The information you will reap from scanning a wide variety of

operating systems depends largely on the construct of the /etc/services file or the

targeted operating system's equivalent. vcp braindump
This file defines what ports and services are

available. This subject will discussed later, as it is relevant to (and implemented

differently on) varied operating systems.

From ISS to SAFEsuite

2008-10-20T18:15:29Z

The first release of ISS stirred some controversy. Many people felt that releasing such a

tool free to the vcp exam prep
Internet community would jeopardize the network's already fragile

security. (The reaction to Dan Farmer's SATAN was very similar.) After all, why release

a product that automatically detects weaknesses in a remote target? In the manual pages

for ISS, the author (Christopher Klaus) addressed this issue by writing:

...To provide this to the public or at least to the security-conscious crowd may cause people to

think that it is too dangerous for the public, but many of the (cr/h)ackers are already aware of these

security holes and know how to exploit them. These security holes are not deep in some OS

routines, but standard misconfigurations that many domains on Internet tend to show. Many of

these holes are warned about in CERT and vcp exam guide
CIAC advisories...

In early distributions of ISS, the source code for the program was included in the

package. (This sometimes came as a shar or shell archive file and sometimes not.) For

those interested in examining the components that make a successful and effective

scanner, the full source for the older ISS is included on the CD-ROM that accompanies

this book.

ISS has the distinction of being one of the mainstays of Internet security. It can now be

found at thousands of sites in various forms and versions. It is a favorite of hackers and

crackers alike, being lightweight vcp exam dumps
and easy to compile on almost any UNIX-based

platform. Since the original release of ISS, the utility has become incredibly popular. The

development team at ISS has carried this tradition of small, portable security products

onward, and SAFEsuite is its latest effort. It is a dramatic improvement over earlier

versions.

SATAN (Security Administrator's Tool for Analyzing Networks)

2008-10-20T18:14:28Z

SATAN is a computing curiosity, as are its authors. SATAN was released (or unleashed)

on the Internet in VCP-310 pass4sure
April, 1995. Never before had a security utility caused so much

controversy. Newspapers and magazines across the country featured articles about it.

National news broadcasts warned of its impending release. An enormous amount of hype

followed this utility up until the moment it was finally posted to the Net.

SATAN is, admittedly, quite a package. Written for UNIX workstations, SATAN was--at

the time of its release--the only X Window System-based vcp exams
security program that was truly

user friendly. It features an HTML interface, complete with forms to enter targets, tables

to display results, and context-sensitive tutorials that appear when a hole has been found.

It is--in a word--extraordinary.

SATAN's authors are equally extraordinary. Dan Farmer and Weitse Venema have both

been deeply involved in security. Readers who are unfamiliar with SATAN might

remember Dan Farmer as the co-author of COPS, which has become a standard in the

UNIX community for checking one's network for security holes. Venema is the author of

TCP_Wrapper. (Some people considervcp exam questions
TCP_Wrapper to be the grandfather of firewall

technology. It replaces inetd as a daemon, and has strong logging options.) Both men are

extremely gifted programmers, hackers (not crackers), and authorities on Internet

security.

SATAN was designed only for UNIX. It is written primarily in C and Perl (with some

HTML thrown in for user friendliness). It operates on a wide variety of UNIX flavors,

some with no porting at all and others with moderate to intensive porting.

NSS (Network Security Scanner)

2008-10-20T18:13:23Z

NSS (Network Security scanner) is a very obscure scanner. If you search for it using a

popular search engine, you VCP-310 Dumps
will probably find fewer than 20 entries. This doesn't mean

NSS isn't in wide use. Rather, it means that most of the FTP sites that carry it are

shadowed or simply unavailable via archived WWW searches.

NSS differs from its counterparts in several ways, the most interesting of which is that it's

written in Perl. (SATAN is also partially written in Perl. ISS and Strobe are not.) This is

interesting because it means that the user does not require a C compiler. This might seem

like a small matter, but it's not. Crackers and hackers generally start out as students.

Students may acquire shell accounts on UNIX servers, true, but not every system

administrator allows his or her users access to a C compiler. On the other hand, Perl is so

widely used for CGI programming that most users VCP-310 Pdf
are allowed access to Perl. This makes

NSS a popular choice. (I should explain that most scanners come in raw, C source. Thus,

a C compiler is required to use them.)

Also, because Perl is an interpreted (as opposed to compiled) language, it allows the user

to make changes with a few keystrokes. It is also generally easier to read and understand.

(Why not? It's written in plain English.) To demonstrate the importance of this, consider

the fact that many scanners written in C allow the user only minimal control over the scan

(if the scanner comes in binary VCP-310 study guide
form, that is). Without the C source code, the user is

basically limited to whatever the programmer intended. Scanners written in Perl do not

generally enforce such limitations and are therefore more easily extensible (and perhaps

portable to any operating system running Perl 4 or better).

Network Utilities

2008-10-20T18:12:20Z

Sometimes people erroneously refer to network utilities as scanners. It is an easy mistake

to make. In fact, VCP-310 Exam Dumps
there are many network utilities that perform one or more functions that

are also performed during a bona fide scan. So, the distinction is significant only for

purposes of definition.

Because we are focusing on scanners, I would like to take a moment to illustrate the

distinction. This will serve two purposes: VCP-310 Free
First, it will more clearly define scanners.

Second, it will familiarize you with the rich mixture of network resources available on

the Internet.

The network utilities discussed next run on a variety of platforms. Most of them are

ported from UNIX environments. Each utility is valuable to hackers and crackers.

Surprisingly, garden-variety network utilities can tell the user quite a bit, and these

utilities tend to arouse less suspicion. In fact, many of them are totally invisible to the

target host. This is in sharp contrast to most scanners, which leave a large footprint, or

evidence of their existence, behind.VCP-310 Vce
In this respect, most of these utilities are suitable for

investigating a single target host. (In other words, the majority of these utilities are not

automated and require varying levels of human interaction in their operation.)

The Government

2008-10-20T18:11:09Z

government and foreign powers. (Though, to be honest, the majority of Internet warfare

that our governmentVCP-310 Practice Exam
has waged has been against domestic hackers. I will briefly discuss

that issue a little later on in this section.)

One would imagine that the U.S. government is amply prepared for Internet warfare.

Well, it isn't. Not yet. However, recent research suggests that it is gearing up for it. In a

1993 paper, specialists from Rand Corporation posed the question of whether the United

States was prepared for a contingency it labeled cyberwar. The authors of that paper

posed various questions about the U.S.'s readiness and made recommendations for

intensive study on the subject:

Indeed, the subject of cyberwar is a popular one. Many researchers are now involved in

assessing the capability of U.S. government agencies to successfully repel or survive a

comprehensive attack from foreign powers. John Deutch, head of the CIA, recently

addressed the U.S. Senate regarding attacks against our national information

infrastructure. In that address, the nation's chief spy told of a comprehensive assessment

of the problem:

We have a major national intelligence estimate underway which will bring together all parts of the

community, including the VCP-310 Practice Test
Department of Justice, the Defense Information Systems Agency, the

military, the FBI, criminal units from the Department of Justice in providing a formal intelligence

estimate of the character of the threats from foreign sources against the U.S. and foreign

infrastructure. We plan to have this estimate complete by December 1 of this year.

How likely is it that foreign powers will infiltrate our national information infrastructure?

That is difficult to say because the government now, more than ever, is getting quiet

about its practices of security on the Net. However, I would keep a close eye in the near

future. Recent events have placed the government on alert and it has intentions, at least,

of securing that massive (andVCP-310 Rapidshare
constantly changing) entity called the Internet. I do know

this: There is a substantial movement within the government and within research

communities to prepare for Internet warfare on an international scale.

Internet Service Providers

2008-10-20T18:10:05Z

Internet service providers (ISPs) are the most likely to engage in warfare, immediately

followed by universities. I wantTestking pdf
to address ISPs first. For our purposes, an ISP is any

organization that provides Internet access service to the public or even to a limited class

of users. This definition includes freenets, companies that provide access to their

employees, and standard ISPs that provide such services for profit. Internet access

service means any service that allows the recipient of such service to access any portion

of the Internet, including but not limited to mail, Gopher, HTTP, Telnet, FTP, or other

access by which the recipient of such services may traffic data of any kind to or from the

Internet.

ISPs are in a unique position legally, commercially, and morally. They provide service

and some measure of confidentiality to their users. In that process, they undertake a

certain amount of liability. Unfortunately,VCP-310 Test
the parameters of that liability have not yet

been adequately defined in law. Is an ISP responsible for the content of its users'

messages?

Suppose users are utilizing the ISP's drives to house a pirated software site. Is the ISP

liable for helping facilitate criminal activity by failing to implement action against

pirates?

If a cracker takes control of an ISP and uses it to attack another, is the first ISP liable?

(Did it know or should it have known its security was lax and thus the damages of the

victim were foreseeable?)

If a user retouches trademarked, copyrighted cartoon characters into pornographic

representations and posts them on a Web page, is the ISP at fault?

These are questions that have yet to be answered. And from the first case where a

plaintiff's attorneys manage to hoist that liability onto ISPs, the freedom of the Internet

will begin to wither and die. These are not the only problems facing ISPs.

Because they provide Internet access services, they have one or more (usually thousands

of) individuals logged into VCP-310 TestKing
their home network. This presents a terrific problem: No

matter how restrictive the policies of an ISP might be, its users will always have some

level of privilege on the network. That is, its users must, at a minimum, have access to

log in. Frequently, they have more.

List Linking

2008-10-20T18:08:40Z

List linking is becoming increasingly common. The technique yields the same basic

results as an e-mail pass 4 sure ccnp
bomb, but it is accomplished differently. List linking involves

enrolling the target in dozens (sometimes hundreds) of e-mail lists.

E-mail lists (referred to simply as lists) are distributed e-mail message systems. They

work as follows: On the server that provides the list service, an e-mail address is

established. This e-mail address is really a pointer to an executable program. This

program is a script or binary file that maintains a database (usually flat file) of e-mail

addresses (the members of the list). Whenever a mail message is forwarded to this special

e-mail address, the text of that message is pass 4 sure download
forwarded to all members on the list (all e-mail

addresses held in the database). These are commonly used to distribute discussions on

various topics of interest to members.

E-mail lists generate a lot of mail. For example, the average list generates 30 or so

messages per day. These messages are received by each member. Some lists digest the

messages into a single-file format. pass 4 sure website
This works as follows: As each message comes in, it is

appended to a plain text file of all messages forwarded on that day. When the day ends

(this time is determined by the programmer), the entire file--with all appended messages-

-is mailed to members. This way, members get a single file containing all messages for

the day.

The E-Mail Bomb

2008-10-20T18:07:49Z

The e-mail bomb is a simple and effective harassment tool. A bomb attack consists of

nothing more pass 4 sure exams
than sending the same message to a targeted recipient over and over again.

It is a not-so-subtle form of harassment that floods an individual's mailbox with junk.

Depending upon the target, a bomb attack could be totally unnoticeable or a major

problem. Some people pay for their mail service (for example, after exceeding a certain

number of messages per month, they must pay for additional e-mail service). To these

individuals, an e-mail bomb could be costly. Other individuals maintain their own mail

server at their house or office. Technically, if they lack storage, one could flood their

mailbox and therefore prevent other messages from getting through. This would

effectively result in a denial-of-service attack. (A denial-of-service attack is one that

degrades or otherwise denies computer pass 4 sure mcse
service to others.In general, however, a bomb attack (which is, by the

way, an irresponsible and childish act) is simply annoying. Various utilities available on

the Internet will implement such an attack.

One of the most popular utilities for use on the Microsoft Windows platform is Mail

Bomber. It is distributed in a file called bomb02.zip and is available at many cracker

sites across the Internet.pass 4 sure a+
The utility is configured via a single screen of fields into which

the user enters relevant information, including target, mail server, and so on

Internet Warfare

2008-10-20T18:06:34Z

The Internet is an amazing resource. As you sit before your monitor, long after your

neighbors areTestkiller dumps
warm and cozy in their beds, I want you to think about this: Beyond that

screen lies 4,000 years of accumulated knowledge. At any time, you can reach out into

the void and bring that knowledge home.

There is something almost metaphysical about this. It's as though you can fuse yourself to

the hearts and minds of humanity, read its innermost inspirations, its triumphs, its

failures, its collective contributions to us all. With the average search engine, you can

even do this incisively, weeding out the noise of things you deem nonessential.

For this reason, the Internet will ultimately revolutionize education. I'm not referring to

home study or classes that save time by virtue of teaching 1,000 students simultaneously.

Although these are all useful techniques of instruction that will undoubtedly streamline

many tasks for teachers and students alike, I am referring to something quite different.

Today, many people have pass 4 sure ccna
forgotten what the term education really means. Think back to

your days at school. In every life there is one memorable teacher: One person who took a

subject (history, for example) and with his or her words, brought that subject to life in an

electrifying display. Through whatever means necessary, that person transcended the

identity of instructor and entered the realm of the educator. There is a difference: One

provides the basic information needed to effectively pass the course; the other inspires.

The Internet can serve as a surrogate educator, and users can now inspire themselves. The

other night, I had dinner with a heavy-equipment operator. Since his childhood, he has

been fascinated with deep space. Until recently, his knowledge of it was limited,

primarily because he didn't have enough resources. He had a library card, true, but this

never provided him with more than those books at his local branch. Only on two

occasions had he ever pass 4 sure testing engine
ordered a book through inter-library loan. At dinner, he explained

that he had just purchased a computer and gone online. There, he found a river of

information. Suddenly, I realized I was no longer having dinner with a heavy-equipment

operator; I was dining with an avid student of Einstein, Hawking, and Sagan. His talk was

so riveting that I went away hungry for lack of having eaten.

The Future

2008-10-20T18:05:00Z

There have been many projections about where the Internet is going. Most of these

projections (atTestking dumps
least those of common knowledge to the public) are cast by marketeers

and spin doctors anxious to sell more bandwidth, more hardware, more software, and

more hype. In essence, America's icons of big business are trying to control the Net and

bend it to their will. This is a formidable task for several reasons.

One is that the technology for the Internet is now moving faster than the public's ability

to buy it. ForActualtest dumps
example, much of corporate America is intent on using the Internet as an

entertainment medium. The network is well suited for such purposes, but implementation

is difficult, primarily because average users cannot afford the necessary hardware to

receive high-speed transmissions. Most users are getting along with modems at speeds of

28.8Kbps. Other options exist, true, but they are expensive. ISDN, for example, is a

viable solution only for folks with funds to spare or for companies doing business on the

Net. It is also of some significance that ISDN is more difficult to configure--on any

platform--than the average modem. For some of my clients, this has been a significant

deterrent. I occasionally hear from people who turned to ISDN, found the configuration

problems overwhelming, and found themselves back at 28.8Kbps with conventional

modems. Furthermore, in certain parts of Troytec dumps
the country, the mere use of an ISDN telephone

line costs money per each minute of connection time.

The Internet: How Big Is It?

2008-10-20T18:04:08Z

This section requires a bit more history, and I am going to run through it rapidly. Early in

the 1980s, the Internet mcse test inside
as we now know it was born. The number of hosts was in the

hundreds, and it seemed to researchers even then that the Internet was massive. Sometime

in 1986, the first freely available public access server was established on the Net. It was

only a matter of time--a mere decade, as it turned out--before humanity would storm the

beach of cyberspace; it would soon come alive with the sounds of merchants peddling

their wares.

By 1988, there were more than 50,000 hosts on the Net. Then a bizarre event took place:

In November of that year, a worm program was released into the network. This worm

infected numerous machines (reportedly over 5,000) and left them in various stages of

disrupted service or distress (I will discuss this event in Chapter 5, "Is Security a Futile

Endeavor?"). This brought the Internet into the public eye in a big way, plastering it

across the front pages of our nation's newspapers.

By 1990, the number of Internet hosts exceeded 300,000. For a variety of reasons, the

U.S. government released its hold on the network in this year, leaving it to the National

Science Foundation (NSF). The Pass4sure dumps
NSF had instituted strong restrictions against commercial

use of the Internet. However, amidst debates over cost considerations (operating the

Internet backbone required substantial resources), NSF suddenly relinquished authority

over the Net in 1991, opening the way for commercial entities to seize control of network

bandwidth.

Still, however, the public at large did not advance. The majority of private Internet users

got their access from providers like Delphi. Access was entirely command-line based and

far too intimidating for the average user. This changed suddenly when revolutionary

software developed at the University of Minnesota was released. It was called Gopher.

Gopher was the first Internet navigation tool for use in GUI environments. The World

Wide Web browser followed soon thereafter.

In 1995, NSF retired entirely from its long-standing position as overseer of the Net. The

Internet was completely commercialized almost instantly as companies across America

rushed to get connected to Certifyme dumps
the backbone. The companies were immediately followed by

the American public, which was empowered by new browsers such as NCSA Mosaic,

Netscape Navigator, and Microsoft Internet Explorer. The Internet was suddenly

accessible to anyone with a computer, a windowing system, and a mouse.

UNIX in Relation to Internet Security

2008-10-20T18:03:18Z

formidable task. This is in contrast to servers implemented on the Macintosh or IBMcompatible

platforms. The operating systems most common to these platforms do not

support anywhere close to the number of network protocols natively available under

UNIX.

Traditionally, UNIX security has been a complex field. In this respect, UNIX is often at

odds with itself. UNIX was developed as the ultimate open system (that is, its source

code has long been freely available, the system supports a wide range of protocols, and

its design is uniquely oriented to facilitate multiple forms of communication). These

attributes make UNIX the test inside ccna
most popular networking platform ever devised. Nevertheless,

these same attributes make security a difficult thing to achieve. How can you allow every

manner of open access and fluid networking while still providing security?

Over the years, many advances have been made in UNIX security. These, in large part,

were spawned by governmental use of the operating system. Most versions of UNIX have

made it to the Evaluated Products List (EPL). Some of these advances (many of which

were implemented early in the operating system's history) include

� Encrypted passwords

� Strong file and directory-access control

� System-level authentication procedures

� Sophisticated logging facilities

UNIX is used in many environments that demand security. As such, there are hundreds of

security programs available to ccna test inside
tune up or otherwise improve the security of a UNIX

system. Many of these tools are freely available on the Internet. Such tools can be

classified into two basic categories:

� Security audit tools

� System logging tools

Security audit tools tend to be programs that automatically detect holes within systems.

These typically check for known vulnerabilities and common misconfigurations that can

lead to security breaches. Such tools are designed for wide-scale network auditing and,

therefore, can be used to test inside mcse
check many machines on a given network. These tools are

advantageous because they reveal inherent weaknesses within the audited system.

However, these tools are also liabilities because they provide powerful capabilities to

crackers in the void. In the wrong hands, these tools can be used to compromise many

hosts.

What Kinds of Applications Run on UNIX?

2008-10-20T18:02:23Z

Many types of applications run on UNIX. Some of these are high-performance

applications for use inmcse Troytec
scientific research and artificial intelligence. I have already

mentioned that certain high-level graphics applications are also common, particularly to

the SGI platform. However, not every UNIX application is so specialized or eclectic.

Perfectly normal applications run in UNIX, and many of them are recognizable names

common to the PC and Mac communities (such as Adobe Photoshop, WordPerfect, and

other front-line products).

Equally, I don't want readers to get the wrong idea. UNIX is by no means a platform that

lacks a sense Troytec ccna
of humor or fun. Indeed, there are many games and amusing utilities

available for this unique operating system.

Essentially, modern UNIX is much like any other platform in this respect. Window

systems tend to come with suites of applications integrated into the package. These

include file managers, text editors, mail tools, clocks, calendars, calculators, and the usual

fare.

There is also a rich collection of multimedia software for use with UNIX, including

movie players, audio CDccna Troytec
utilities, recording facilities for digital sound, two-way camera

systems, multimedia mail, and other fun things. Basically, just about anything you can

think of has been written for UNIX.