Calgary Alberta Canada USA Computer
Forensics Data Recovery Investigation
Computer Forensic Investigations
Definitions
In
order to assist potential clients with a better understanding
of some of the actions and terminologies involved in computer
investigations and forensics, we have created this page
helps explain some of the more common issues addressed.
Most importantly, if followed in order, the reader will
gain a very thorough understanding of how data is created,
saved, and most importantly, what happens when it is deleted.
INTERNET PROTOCOL ADDRESS (IP)
The Internet Protocol (IP) Address is a unique address issued
to a computer by the Internet service provider for the period
that the computer is connected to the Internet. No two computers
can have the same address at the same time. The IP address
is comprised of 4 groups of numbers or octets, and each
octet number can be from 0-255. An example is 255.255.255.255.
Again, this IP address is as unique as a house address.
No two houses can have the same address. To paint a picture,
I will explain how the process works. When your computer
attempts to connect to the Internet, either manually by
dial up, or automatically via cable or DSL, the computer
actually starts to communicate with your Internet service
provider (ISP). This is the company you purchase your monthly
access from, such as AOL, Earthlink, Comcast Cable, etc.
For the purpose of explanation, I will use Comcast Cable
Communications (CCC) as the ISP for my example. When you
attempt to go online, your computer will communicate with
a SERVER computer at CCC. Your computer will
ask for an IP address so that it can access the Internet.
CCC verifies your computers right to have the access,
and will then issue the IP address, thereby connecting you
to the Internet. Once you turn your computer off, the IP
address is relinquished. It is possible to get the same
IP address on different occasions, however not very likely.
In the case of ISPs that provide service via cable, such
as CCC, it is possible to hold the same IP address indefinitely,
depending on your type of account and connection. Each ISP
either purchases or leases a range of IP addresses to issue
to its customers based on rules and guidelines mandated
by an organization called ICANN.
This
IP address is attached to every email that is sent from a
computer. When an email is sent, it passes through a minimum
of 2 computers, and more usually, at least 4. Each of these
computers tags the email with their IP address, allowing a
qualified expert to trace the exact path of the email. In
some instances, the expert can then utilize Internet Profiling
techniques to further identify the sender. When this profiling
does not work, or as a basis for more conclusive proof, a
subpoena, warrant, or Anton Pillar Order can be issued to
the ISP compelling them to provide subscriber information
for the computer connected to the IP address at the date and
time specified.
DATA
A computer uses machine language at its lowest level. This
is the zeros and ones in a computer. The zeros and ones are
utilized in such a way that they represent recognizable characters.
Each zero and each one is known as a BIT. In order to create
a letter, number, or other recognizable character, it takes
8 bits. In other words, to create the letter A, the computer
uses a combination of 8 zeros and ones. 8 BITS are equal to
one BYTE. Therefore, I can state that a typed character that
you see on the screen is 8 BITS or 1 BYTE. In the example
of the word DEFINITION, it would be a total of
10 bytes in length. 1024 bytes equals 1 KILOBYTE. This is
important to understanding how data occupies space, and monumental
in understanding how data gets somewhere on a computer, stays
there after deletion, or is wiped from there.
HARD
DRIVE STRUCTURE
A hard drive cannot just be an unorganized open space containing
bits and bytes. It must be structured in such a way that data
can be found efficiently. To this end, a hard drive is divided
up into small spaces that can then be referenced by the Operating
System to more efficiently find data and bring it to the user.
The smallest space created on a hard drive is called a SECTOR.
A sector is always 512 bytes in size. Another way to say this
is that there can be 512 letters or other characters in one
sector, but no more.
To
give an idea of how big this is, let us look at the following
paragraph:
Here
lived once upon a time a wicked prince whose heart and mind
were set upon conquering all the countries of the world, and
on frightening the people; he devastated their countries with
fire and sword, and his soldiers trod down the crops in the
fields and destroyed the peasants huts by fire, so that
the flames licked the green leaves off the branches, and the
fruit hung dried up on the singed black trees. Many a poor
mother fled, her naked baby in her arms, behind the still
smoking walls of her cottage.
The
above paragraph contains exactly 512 characters and therefore,
is 512 bytes or 1 sector in size. As a comparison, the average
80 GB hard drive contains approximately 156,280,257 sectors.
The
next division that exists on a hard drive is a CLUSTER. A
cluster is a collection of SECTORS. The exact number of sectors
in a cluster can vary depending on the size of the hard drive,
the operating system used, and the users preference.
A very common cluster size is 4 Kilobytes. In that case, the
cluster would hold 8 sectors. The smaller the cluster (less
amount of sectors), the more efficient the use of hard drive
space; the larger the cluster (more sectors), the easier it
is to catalogue and retrieve data. Put another way, a Sector
would be like a filing cabinet drawer, and a Cluster would
be like the entire filing cabinet. Clusters are usually what
we talk about when we talk about hard drive space, and so
from this point on, I will be referring to clusters.
Given
the explanation above, let us look at the paragraph below.
Here
lived once upon a time a wicked prince whose heart and mind
were set upon conquering all the countries of the world, and
on frightening the people; he devastated their countries with
fire and sword, and his soldiers trod down the crops in the
fields and destroyed the peasants huts by fire, so that
the flames licked the green leaves off the branches, and the
fruit hung dried up on the singed black trees. Many a poor
mother fled, her naked baby in her arms, behind the still
smoking walls of her cottage; but also there the soldiers
followed her, and when they found her, she served as new nourishment
to their diabolical enjoyments; demons could not possibly
have done worse things than these soldiers!
This
paragraph contains 711 characters, or bytes. In the case of
the subject hard drive, the red at the left below would represent
a proportional amount of the above text as it would occupy
a cluster. The blue in our example below indicates SLACK SPACE
which I will explain later in this page.

In
the case of photographs, they take up much more space than
a set of text. A relatively small picture as may be found
on the Internet could be in the range of 5-40 KB. The photo
below is actually 24 KB in its native form on the Internet.

In
being 25 KB, in my example below, it would occupy the indicated
space in the clusters shown in red.

SLACK
SPACE
As stated before, the red indicates the above picture on a
hard drive. You can see that it doesnt cover the entire
7th cluster. When Windows stores a file, it fills as many
clusters as needed, but except in the rare instance of a perfect
fit, a portion of the final storage cluster will be left unfilled
with new data, as indicated by the blue. The space between
the end of the file and the end of the cluster is called SLACK
SPACE or FILE SLACK as indicated in blue.
Using
another explanation, suppose your office uses 500-page notebooks
to write out all documents. It is your office policy that
no two documents will share a notebook. One document, one
notebook. If your document is only 10 pages long, you must
dedicate an entire notebook to the task. Once in use, you
can add another 490 pages, until the notebook won't hold another
sheet. For the 501st page and beyond, you have to use a second
notebook. The difference between the last word of the document
and the end of the notebook is its slack space. Smaller notebooks
would mean less slack, but you'd have to keep track of many
more volumes.
It
is important to understand that the slack space I am talking
about is viewed by the computer as used space, even though
it may be empty. In some cases, this can mean that even though
a hard drive is deemed to be full, it actually has as much
as 40% of empty space.
For
the purposes of my explanations, I will refer to data in two
ways. Resident Data, which is data that currently exists on
the hard drive in its normal form, and Deleted Data, which
is data that is deleted.
DATA
DELETION
DELETED files and data refer to files and data that a user
has deleted by normal means. In other words, has sent to the
Recycle Bin on the users desktop. It further refers
to any of the data that would then be emptied from the Recycle
Bin. At this point, most people would believe the data is
truly gone forever. In actual fact, it becomes relegated to
a portion of the hard drive called UNALLOCATED SPACE. This
space is the space of the hard drive that a user cannot see.
If you have a 20 GB hard drive, but you have only stored 5
GB of data on it, the other 15 GB is called UNALLOCATED SPACE.
MASTER
FILE TABLE
When
deletion of a file occurs, the file doesnt actually
disappear. As I explained earlier, the clusters hold specific
files. Given that hard drives have millions of clusters, the
computer needs a way to find a specific one. The way it does
this is through the use of a MASTER FILE TABLE or MFT for
short. This MFT is basically a table of contents that points
to individual clusters. If a user creates the file in my example
above, and calls it The Little Prince, it will be saved to
a space covering one cluster. We will say for the sake of
explanation that it saved the document to cluster number 3,000,000.
An entry will now be made in the MFT so the next time I double
click on the icon to open the document, the computer will
be told by the MFT where to go find it. If I then delete the
document or reformat the drive, it will still exist on cluster
3,000,000, but the entry in the MFT is what actually gets
removed. Once the MFT has had the document reference removed,
the computer no longer knows where to go and look for it.
As well, the computer is told that it is perfectly OK to place
a new document on cluster 3,000,000. BUT, until it actually
does, the old data is still there. With our expertise and
specialized software, we are able to access the Unallocated
Space and find the document based on various parameters. We
can also use that software and expertise to actually restore
the once deleted file to useable status again.
Let
us take this explanation one step further. Let us suggest
that I had deleted the file mentioned above, or reformatted
the entire drive. At some point, I then created a new document
as below.
Mary
had a little lamb, its fleece was white as snow. Everywhere
that Mary went, the lamb was sure to go.
When
I saved it, through the normal allocation of space by the
computer, it got saved to cluster 3,000,000. It is actually
only 105 characters, or bytes in size. However, based on the
explanation outlined above, the entire cluster is set aside
for the document. When this occurs, the first 105 bytes of
the cluster have now been overwritten by the new data, but
the rest of old data in the Slack Space is still present.
As well, because the cluster now houses a new document of
105 bytes, the rest of the cluster will never be overwritten
by anything else, meaning that the old data will always be
there to find, at least until the new document is deleted.
To give a further graphic representation of what I have just
explained, I will show the cluster allocation again below.

As
you can see, my new document (in green) has covered up some
of the old document that used to exist there. From the above
picture, the cluster indicated now cannot be written to by
anything else. I can still then recover the old information
that exists in what is now the new Slack Space. Below is a
depiction of how the document would look in my forensic program.
This will make things easier to understand. The only data
placed below is the data that exists on the one cluster.
Mary
had a little lamb, its fleece was white as snow. Everywhere
that Mary went, the lamb was sure to go.es
of the world, and on frightening the people; he devastated
their countries with fire and sword, and his soldiers trod
down the crops in the fields and destroyed the peasants
huts by fire, so that the flames licked the green leaves off
the branches, and the fruit hung dried up on the singed black
trees. Many a poor mother fled, her naked baby in her arms,
behind the still smoking walls of her cottage.
As
you can see, even though I deleted a document and wrote another
document on top of it, I can still see most of the old document.
The
Windows system is designed to be blind to all information
in the slack space. Searching is accomplished using a forensically
sound copy of the drive and specialized examination software.
File
slack is, by its very nature, fragmented, and the information
identifying file type is often the first data to be obscured.
The
search for plain-text information is typically the most fruitful
avenue in file slack examination and an exercise often measured
in hours, days, or weeks of review.
DATA
ALLOCATION
In most cases, as a user uses a computer, the data they create,
generate, download, or, in the case of the Internet, merely
view gets stored on the hard drive, sometimes in more than
one place. As an example, if you were to visit the webpage
located at http://www.computerpi.com, you would be viewing
the writers home page. Without doing ANYTHING else,
a record has been created on your computer that you visited
this page. This creation includes:
- Copy
of the page automatically downloaded to your hard drive;
- Each individual picture or image on that page separately
downloaded to your hard drive;
- The URL, or page name saved to a number of different locations
on your hard drive;
- A reference to the page inside a file called index.dat;
- Dates and times of activity relative to this page.
ALL
OF THIS INFORMATION IS RECOVERABLE if it has not yet been
overwritten.
In
the case of a document or file that you might create, for
example, MyLetter.doc, not only is the original document saved
to your computer when you create it, but every time you open
it, make changes to it, and save it, a newer copy is basically
created, although the computer only references the latest
one. It is extremely common to search for a document forensically
through a text string and come up with a number of various
instances of it. Besides this, an entry is made in a number
of different places, such as a folder called Recent Documents
that shows the file was recently accessed.
RECOVERED
FOLDERS
RECOVERED FOLDERS are folders that contain data that was recovered
using a forensic data recovery program. In order for a file
to be recovered by the program in the fashion used in this
case, it must NOT be overwritten by any other data at all.
FILE
WIPING
WIPING files and data is different from deleting them. A wiping
program endeavours to remove any and all traces of a file
from the computer in any of the areas that it may exist. In
my examples above, I indicated that saving new data to an
old cluster will overwrite only as much as it needs, leaving
any old data still visible to the trained eye. A FILE WIPING
PROGRAM will actually go to that cluster and over write all
of the old data so as to destroy it. The file wiping program
actually overwrites the file it is deleting with other data,
such as zeros, or in many cases, whatever the user wants to
over write with. A Wiping Program can contain numerous configuration
options such as changing MetaData, changing or obfuscating
folder and file names, and generating false names and amounts
of files. There are certain places that a Wiping Program cannot
access. Essentially, a file cannot be changed, deleted, etc
by an outside program if it is open and in use. This includes
file wiping programs. They wipe a great many files, but they
cant do anything to any files that are currently in
use, such as the Registry files and other Windows operating
system files that are opened upon boot up of the computer.
To further explain file wiping, the below is an example of
raw data from unallocated file space that has been undisturbed.
This
is a chunk of deleted data that has been deleted normally,
with no effort to actually wipe it:
ÿØÿà
JFIF ÿÛ C #%$""!&+7/&)4)!"
0A149;>>>%.DIC<H7=>;ÿÛC ("(;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;; ÿÀ e ÷ " ÿÄ
ÿĵ} !1A Qa"q 2?¡#B ±Á
RÑð$3br %&'() *456789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz
¢£
¤¥¦§¨©ª²³´µ¸¹
ºÂÃÄÅÆÇÈÉÊÒÓ
ÔÕÖרÙÚáâãäå
æçèéêñòóôõö÷
øùúÿÄ ÿĵw!1AQaq
"2? B¡ #3Rð brÑ $4á%ñ
&'()*56789: CDEFGHIJSTUVWXYZcdefghijstuvwxyz
¢
£¤¥¦§¨©ª²³´µ¸¹
ºÂÃÄÅÆÇÈÉÊÒÓÔ
ÕÖרÙÚâãäåæçèé
êòóôõö÷øùúÿÚ
?öj(¢€(¢ €(¢€ÅñWm¼¤}hye`?Ó6v®ã$ôõ8j¸Ï
Eö©áÛ9lÞåôýB
%$»?;ÍqÀ?Jµ¤x
P?ÅðkðÛAÖî =ÞL«Ñk
T OÌ ~^ A«øÎ{OZ ë Ù<<ï}
$ÂL±òØ0 ÈÈ99(ù}ÿâä:ö?*
×HòMâÄò cµ[¡8ÈíÂñ\sÜ\jº£5Åï
Äz àqn
Z0±€D?cÎ
p ÚõÚÌúúçÄ7
±Û "éÖ w$;ÎÛX*UKw.
I
know by looking at this, that it is the beginning of a picture
that was deleted. If it had been wiped, the same space would
look more like the following:
yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
In
other words, a wipe utility works off the premise that you
must overwrite every bit of information that was previously
there in order to obliterate it. Wipe programs use patterns
such as the above to ensure they cover everything. Patterns
like this are visible. In the case of the subject hard drives,
we observed no obvious instances of the above patterning.
METADATA
When files are created in Windows, a number of things occur
behind the scenes that the average user is generally
unaware of. One of these occurrences is the creation
of what is known as METADATA. METADATA is data added to a
file that can include information such as the authors
name, program used, and most importantly for our purpose,
the date and time stamps of when a file was CREATED, MODIFIED,
and ACCESSED.
CREATED
meta refers to the date and time that the file was created
on a system.
MODIFIED meta refers to the date and time that the
file was modified in someway.
ACCESSED meta refers to the date and time that the
file was opened.
HTML HyperText Markup Language
HTML can best be describes as the programming language that
creates web pages. It is programming that, when written, creates
a set of sequential instructions that, when the computer reads
them, displays a webpage on your screen. This does not happen
all at once. The programming is read from top to bottom, and
this can best be seen with a slow dial up Internet connection,
when you can watch the page load from top to bottom. If the
writer inserts some extra programming within the HTML, called
JAVASCRIPT, he or she can cause an automatic action to occur.
If the action is to open up a new window with an advertisement
in it, this is what will happen once the HTML code is read
to the point that the JAVASCRIPT starts.
POPUP
A POPUP is a page or window - usually small - that pops up
either when a link or linked item is clicked, or by some automatic
or other stimulus. POPUPS are (in many cases) JAVASCRIPT codes
and there are many different varieties.
You
can have a POPUP that will load when you first visit a page,
or when you exit a page and ones that are timed (to popup
in xx seconds after the page is loaded). As opposed to the
usual POPUPS (that you see), there are also "POPUNDERS"
that you won't see until you close the pages, because they
open behind all the pages (and they can also be creating other
POPUPS behind the scenes). A single HTML page can have numerous
POPUP codes in it, so when visiting one page, you can suddenly
find a dozen POPUPS on your screen, and even more when you
exit the page. This is not yet counting any POPUP code that
may be inserted in the new pages that have popped up.
POPUPS
are really only HTML pages that are configured to open at
a specific height and width, so the POPUPS themselves can
have a JAVASCRIPT to create even more POPUPS. That's why you
can find yourself visiting a site, and be utterly hammered
with them. Those POPUPS can also have exit POPUPS, such that
when you close them, another POPUP appears, then another,
then another, and so on, until your browser may even eventually
crash due to the data volume.
JAVASCRIPT
JAVASCRIPT is a programming language that can cause automated
functions to occur, most usually as it is read through the
loading of a web page. In the example of many web page pop
ups, and especially in the cases of pornographic websites,
as a webpage is loaded, it will start reading its code from
top to bottom. When it reaches the JAVASCRIPT part of the
programming, a pop up will occur. In many cases, there can
be JAVASCRIPT programming in the new page that pops up. This
will cause yet another pop up. With this method, you can see
how entering one page can cause numerous other pages to load
automatically. As previously indicated in this report, everything
that is displayed on your computer screen is subsequently
downloaded to your computer without your intervention or specific
action. Numerous continuous popups appearing one after another
in rapid, automatic fashion are called a POPUP ATTACK.
FILE EXTENSION
In relation to computer files, a FILE EXTENSION is an addition
to the file name in the form ".xxx" where "xxx"
represents a limited number of alphanumeric characters depending
on the program that created them. The FILE EXTENSION allows
a file's type or format to be described as part of its name
so that users can quickly understand the type of file it is
without having to open or try to use it. The FILE EXTENSION
also helps an application program recognize whether a file
is a type that it can work with. For example, picture.jpg
would be a picture file, as indicated by the extension .jpg.
Picture.txt would be a text document as indicated by the extension
.txt. In other words, these extensions at the end of a filename
refer to the type of file it is. This information is used
by your operating system to launch an appropriate program
when you click on the filename.
.JPG
EXTENSION
The
.JPG file extension stands for Joint Photographic Experts
Group and can be expressed in an extension as both .JPG and
.JPEG. It is a standardized image compression mechanism designed
for compressing photographic images, often for use on the
Web. JPG is "lossy," meaning that the decompressed
image is not quite of the same quality as the original image.
There are many viewing programs that will display .JPG images,
including Internet Explorer. Put simply, a .JPG file will
be a picture of something.
.BMP
EXTENSION
The .BMP file extension stands for BitMap, and was designed
by Microsoft. It is an inefficient way of displaying images
on the Internet because it does not compress the images, thereby
making them usually quite large. They will be used for small
images on the Internet or are sometimes used to display THUMBNAILS.
Put simply, a .BMP file will be a picture or created graphic
image of something.
.GIF
EXTENSION
The .GIF file extension stands for Graphic Interchange Format
and is a common format for image files, especially suitable
for images containing large areas of the same colour. .GIF
format files of simple images are often smaller than the same
file would be if stored in .JPG format, but GIF format does
not store photographic images as well as .JPG. .GIF images
are widely used as the format of choice for Internet icons
and buttons. Put simply, a .GIF file will be a created graphic
image of something.
.DLL
EXTENSION
Short for Dynamic Link Library, a .DLL file is a file that
contains executable functions or data that can be used by
a Windows application. Typically, a DLL provides one or more
particular functions and a program accesses the functions
by creating either a static or dynamic link to the DLL. A
static link remains constant during program execution while
a dynamic link is created by the program as needed. DLLs can
also contain just data. As one example, a .DLL can contain
all of the possible selectable options for a drop down list
in a program.
.LNK
FILES
Link files are shortcut files and have the file extension
.lnk. Link files refer to or point to a file. These target
files can be applications, directories, documents, or data
files. Clicking on a shortcut causes the target file to run.
If it is an application, the application is launched. If it
is a document, the registered application runs and opens the
document. Certain actions by the user create link files without
their knowledge. Specifically, when a user opens a document,
a link file is created in the Recent folder, which appears
in the root of the user folder named after the user's logon
name. The link files in this folder serve as a record of the
documents opened by the user.
FILE
HEADERS
A FILE HEADER is a unit of information that precedes a data
object (the contents of any particular file). As regards resident
files on the subjects computer, a FILE HEADER is a region
at the beginning of each file where information about that
file is kept. The file header may contain the date the file
was created, the date it was last updated, and the file's
size. More importantly, it also dictates the type or format
of the file. The first few characters of a FILE HEADER show
the computer where to start reading the file from, and how
to view it, among other things. The FILE HEADER can be accessed
only by the operating system or by specialized programs such
as forensic analysis software. Subsequently, for our purposes,
a FILE FOOTER can be used to describe that last few characters
of a file. This will indicate to the computer that this is
the end of the file it is reading. Much like a capital letter
at the beginning of a sentence tells you this is the beginning
of the sentence, and much like a period tells you that you
have reached the end of a sentence, so a FILE HEADER and FILE
FOOTER indicate to the computer the beginning and end of a
particular file. The FILE HEADER of a particular file is always
the same. For example, in the case of a .JPG file, the first
few characters of the FILE HEADER look like this: ÿØÿà..JFIF
and the FILE HEADER for an .XLS file (Microsoft Excel Spreadsheet)
looks like this: ÐÏ.ࡱ.á
In
the case of a FILE FOOTER, these do not necessarily have to
end with the same set of characters, although that is the
norm. A .JPG FILE FOOTER looks like this: ÿÙ
COOKIES
A COOKIE is a piece of information sent by a Web server in
the form of a text file to a user's browser. (A Web server
is the computer that "hosts" a Web site, and responds
to requests from a user's browser, like Internet Explorer.)
COOKIES may include information such as login or registration
identification, user preferences, online "shopping cart"
information, or in most cases, merely the fact that the site
was visited, etc. The browser saves the information, and sends
it back to the Web server whenever the browser returns to
the Web site. The Web server may use the cookie to customize
the display it sends to the user, or it may keep track of
the different pages within the site that the user accesses.
Browsers may be configured to alert the user when a cookie
is being sent, or to refuse to accept cookies. Some sites,
however, cannot be accessed unless the browser accepts cookies.
A user does NOT need to specifically visit a page to get a
COOKIE from that website. A user can be visiting a site at
www.magnets.com and if that webpage has a banner ad for a
different website, that banner could place a COOKIE on your
computer even if you have not clicked on the banner or visited
the site that the banner points to. The maximum size for a
COOKIE is 4 KB.
THUMBNAILS
A THUMBNAIL is an image you frequently find on Web pages.
Usually photo or picture archives will present a THUMBNAIL
version of their contents (makes the page load more quickly)
and when a user clicks on the small image a larger version
will appear. Sometimes these links will be to a new page containing
the larger graphic and other times right to the image directly.
In some cases, the THUMBNAIL can be very misleading in that
it doesnt actually take you to the picture you originally
see. It can actually take you to an entirely different site.
This is seen very frequently on pornographic websites.
TOPLISTS
A TOPLIST is a script driven site with a long list of links
to other websites. The links change their order every few
minutes based on which website is sending the most traffic
(or users) to the site. The objective is to send enough traffic
to the site to stay near the top of the list without being
the person sending the most traffic. The sites listed closest
to the top of the list will usually get the most traffic,
as that is what the user sees first. Usually there will be
a descriptive link or picture with two numbers next to it.
The
last site the traffic came from may not have been what the
user was looking for. It may have been a site full of blondes
when the user was looking for a picture of what looked like
their ex-girlfriend who was a brunette. The better
TOPLISTS offer the user all the different subject flavors
to make the best use of the new traffic they get. The idea
of TOPLISTS is simple. If a website wants to succeed in the
industry, it can't do it alone. It needs to create a network
of sites that utilizes other websites needs to exchange links.
Exchanging links with other sites is the most basic promotion
strategy utilized by the Internet.
TOPLISTS
are legendary for the POPUP attacks they can spawn. It is
not uncommon for a TOPLIST to generate 10-20 or more webpages
that will automatically open all at once on a users
screen. It is also not uncommon for a TOPLIST to have in excess
of 30 THUMBNAILS on it. If that TOPLIST generates a POPUP
ATTACK of 10 pages on a users computer, and each page
has 30 THUMBNAILS, that is a total of 300 pictures which,
as explained before, are automatically downloaded to the users
computer unknown to the user. Given that the user has no control
over what pages appear in a POPUP ATTACK, it is easy to see
how unsolicited pictures of all types could come to reside
on a computer hard drive.
In
a vast majority of cases on the Internet, especially pornography,
these images and links dont actually lead to what they
suggest they are linking a user to.
TGP
TGP stands for Thumbnail Gallery Post. These are websites
that are used by websites as a way to convey a large amount
of images with a limited amount of space and bandwidth. TGPs
allow a website to place a large number of small images on
a page that can be expanded in a popup window. This conserves
physical space on a page, as well as download time since the
user can browse the thumbnails and select images to see in
full size. In a vast majority of cases on the Internet, especially
pornography, these sites lead to POPUP ATTACKS. Also in many
cases, these images and links dont actually lead to
what they suggest they are linking a user to. They are very
frequently linked to and from TOPLISTS, and are seen frequently
as automatically generated POPUPS.
WINDOWS
REGISTRY
The best way to describe the WINDOWS REGISTRY is to suggest
that the computer is like a body. A body has many, many functions,
including moving body parts, breathing, keeping the heart
beating, etc. What keeps these happening? Well, in a nutshell,
it is the Central Nervous System. The brain has the thought
or instruction and the order is carried out based on a default
set of values that have been programmed, such as hunger, movement,
etc. The nerves issue the instruction and if everything goes
well, the task gets completed.
In
a computer, the WINDOWS REGISTRY is the Central Nervous System.
It controls EVERYTHING. It is very susceptible to injury,
just like the body. The difference is that if you cut your
body, you usually know about it right away. In the computer,
if you damage the WINDOWS REGISTRY, you may not become aware
of it for days or weeks or months.
The
WINDOWS REGISTRY is constantly issuing instructions to the
computer virtually from the moment it is turned on. How do
those programs open on startup such as the Anti Virus? The
WINDOWS REGISTRY has told the computer to start them. When
a user double clicks on an icon, how does the computer know
what program to use to open the file? Again, the WINDOWS REGISTRY.
There is virtually no part of a computer that is untouched
by the Registry. In the case of many viruses, Trojan programs,
and worms, the WINDOWS REGISTRY is automatically altered to
carry out the malicious instructions.
As
an example of what a WINDOWS REGISTRY entry looks like, I
will display the key (or entry) that controls what page is
displayed when a user opens their Internet browser such as
Internet Explorer. First you navigate through a set of folders
much the same as in Windows Explorer. When you reach the folder
that contains the Internet Explorer settings, a list of keys
are shown. The key that controls the default home page looks
like this:
"Start
Page"=http://www.xxxxxxxxxxx.com/ (where the xxxxxxxx
is the name of the start page).
|