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Internet Lecture - 3

CSIT100

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Topics

• Internet Protocols

• Freeware

• Open Source software

• What is shareware?

• What is a browser plug-in?

• What is a cookie?

• Spam

• What are “worms”, “viruses”?

• Anti-Spyware ... Trojan horse

• Phishing

• Pharming

• Audio & Video

• Key Logger .. Software

• Firewall

• What happens to deleted files?

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Internet protocols …

• ftp

• telnet

• nntp

• https

• mms

• P2P

• P2P - BitTorrent

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Internet protocols …

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ftp

• The computers on the Internet have a standard tool (program-service) for transferring copies of files. This service is called ftp (file transfer protocol).

• ftp programs:

– FTP Voyager (pay)

– FileZilla (free)

– CuteFTP (pay)

– FireFTP (free)

– WinSCP (free)

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We can transfer ASCII and Binary files

• ASCII file (text, postscript file, e-mail files)

• (ASCII = American Society Code Information Interchange)

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ASCII characters ….

• ASCII file (text, postscript file, e-mail files)

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We can transfer ASCII and Binary files

• ASCII file (text, postscript file, e-mail files)

• Binary files (WORD file, images, voice, compressed files)

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Binary file

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ÿÄ µ } !1AQa"q2�‘¡#B±ÁRÑð$3br‚%&'()*456789:CDEFGHIJSTUVWXYZcdefghijstuvwxyzƒ„…†‡ˆ‰Š’“”•–—

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Š’“”•–—˜™š¢£¤¥¦§¨©ª²³´µ¶·¸¹ºÂÃÄÅÆÇÈÉÊÒÓÔÕÖ×ØÙÚâãäåæçèéêòóôõö÷øùúÿÚ ? ð71½®ºÿ C_/t|Á}:_3n)óœJfq)6ŸJè-´ ç F9®“JðD²`Ì3škRÓ¹çðZI3a5ÑišÄ‚àŽõêG‚£‹cÁ®‚/ª§

Íe4Élâ´%€Å_ÖtÃöW<ŠôAS VƧáÈd²qÞˆÁتNÇÈZ¼BD#£Uí>,âº/‰Z,¶Z¡m¼gükJÈÀ5çã6¹»wW5„•a`Ç5$*1Vvôã5áN¡ÎÛ(±øÓ”Iõ«›qBÇSÎ*

uêXc,B€rk•MЋ!–aœvhÑ�g¡Û„Ë«c,“eg5Ô€F§Íu–I`wÁ\8=sV'K{¼åÏî¾léÍaÍ®c @¹n8ÏéÆ4ðÊËsï²nX•yjËÚ®°÷,±m‡Ž½Gs7»�ótàdTZ„êß2ÏoJ¨Ó{t5ÉV¯2Ôûœ.SI¢rK(Çj”JU9–“•ïR½Ë§"¸•úΕËnß¼#¢•Û2ªò•÷E'˜X×Y�S'’^Ç™æŒz-

Gæg#94Î0riØ»hJ’‡ó¦†éÅVó0qJ%äö⯕•kY…°äÔT’7#Š ²|À†ïRîM ª&YS—Á£8çðªÌ@ž÷(±À�Š\ƒs³°ì�̧èj9Žzx …….

Open an image file with … notepad

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… image

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ÿÄ µ } !1AQa"q2�‘¡#B±ÁRÑð$3br‚%&'()*456789:CDEFGHIJSTUVWXYZcdefghijstuvwxyzƒ„…†‡ˆ‰Š’“”•–—

˜™š¢£¤¥¦§¨©ª²³´µ¶·¸¹ºÂÃÄÅÆÇÈÉÊÒÓÔÕÖ×ØÙÚáâãäåæçèéêñòóôõö÷øùúÿÄ

ÿÄ µ w !1AQaq"2�B‘¡±Á#3RðbrÑ$4á%ñ&'()*56789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz‚ƒ„…†‡ˆ‰

Š’“”•–—˜™š¢£¤¥¦§¨©ª²³´µ¶·¸¹ºÂÃÄÅÆÇÈÉÊÒÓÔÕÖ×ØÙÚâãäåæçèéêòóôõö÷øùúÿÚ ? ð71½®ºÿ C_/t|Á}:_3n)óœJfq)6ŸJè-´ ç F9®“JðD²`Ì3škRÓ¹çðZI3a5ÑišÄ‚àŽõêG‚£‹cÁ®‚/ª§

Íe4Élâ´%€Å_ÖtÃöW<ŠôAS VƧáÈd²qÞˆÁتNÇÈZ¼BD#£Uí>,âº/‰Z,¶Z¡m¼gükJÈÀ5çã6¹»wW5„•a`Ç5$*1Vvôã5áN¡ÎÛ(±øÓ”Iõ«›qBÇSÎ*

uêXc,B€rk•MЋ!–aœvhÑ�g¡Û„Ë«c,“eg5Ô€F§Íu–I`wÁ\8=sV'K{¼åÏî¾léÍaÍ®c @¹n8ÏéÆ4ðÊËsï²nX•yjËÚ®°÷,±m‡Ž½Gs7»�ótàdTZ„êß2ÏoJ¨Ó{t5ÉV¯2Ôûœ.SI¢rK(Çj”JU9–“•ïR½Ë§"¸•úΕËnß¼#¢•Û2ªò•÷E'˜X×Y�S'’^Ç™æŒz-

Gæg#94Î0riØ»hJ’‡ó¦†éÅVó0qJ%äö⯕•kY…°äÔT’7#Š ²|À†ïRîM ª&YS—Á£8çðªÌ@ž÷(±À�Š\ƒs³°ì�̧èj9Žzx …….

Open an image file with … notepad

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… voice (analog – digital)

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0&²uŽfϦ٠ª bÎlæ 3&²uŽfϦ٠ª bÎlê 2 – S y m p h o n y N o . 9 ( S c h e r z o ) L u d w i g v a n B e e t h o v e n , c o m p o s e r . S e a t t l e S y m p h o n y . G e r a r d S c h w a r z , d i r e c t o r @¤ÐÒãÒ—ð É^¨Pª W M / L y r i c s W M F S D K V e r s i o n 8 . 0 0 . 0 0 . 4 3 7 3 W M F S D K N e e d e d 0 . 0 . 0 . 0 0 0 0 W M / C o m p o s e r * L u d w i g v a n B e e t h o v e n W M / P u b l i s h e r V o x W M / G e n r e C l a s s i c a l W M / M C D I L 6 + 9 6 + 1 7 5 5 + 9 3 E F + E A D 3 + 1 3 A A 4 + 1 A 2 E 4 + 1 F 5 B 6 W M / T r a c k N u m b e r W M / Y e a r 2 0 0 2 W M / E n c o d i n g T i m e ËŠ•å¼Ç0 W M / U n i q u e F i l e I d e n t i f i e r b A M G a _ i d = R 6 8 8 7 3 7 ; A M G p _ i d = V A ; A M G t _ i d = T 6 9 3 3 8 8 2 W M / A l b u m T i t l e . B e e t h o v e n [ V o x ] D i s c 1 W M / A l b u m A r t i s t V a r i o u s A r t i s t s W M / P r o v i d e r A M G " W M / P r o v i d e r S t y l e C l a s s i c a l Îuø{�FÑ�‚ ̀ —É¢² ˆü ¡Ü«ŒG©ÏŽä À Seh í“ÿ[¨†J‘~‰¾›„âTPp

0׿òxÎÀÌ `². 0Îò, ( ººˆü µ¿_.©ÏŽã À Se¤ ÒÓ«º©ÏŽæ À Se v ”#D˜”ÑI¡ANEpTv . W M / M e d i a C l a s s P r

i m a r y I D ¼}`Ñ#ãâK†¡H¤*(D 2 W M / M e d i a C l a s s S e c o n d a r y I D W M / W M C o n t e n t I D zv�ÒPÕåLœJÍòáî½ $ W M / W M C o l l e c t i o n I D Lôââ¹Iž×

véÚ.¥ . W M / W M C o l l e c t i o n G r o u p I D Lôââ¹Iž× véÚ.¥tÔßÊ E¤ºš«Ë–ªè

… voice

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ASCII and Binary Files

ASCII Files:

.htm .html .shtml .php .pl .cgi .js .cnf .css

.forward .htaccess .map .pwd .txt .grp .ctl

Binary Files:

.jpg .gif .png .tif .exe .zip .sit .rar .ace

.class .mid .ra .avi .ocx .wav .mp3 .au

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Telnet software: DXTelnet

• An Internet protocol that allows you to log in to remote computer on the Internet.

• TelNet also provides access to library systems, databases and information resources.

• Telnet (Telecommunications network )

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nntp

• Protocol that supports the distribution, retrieval and posting of usenet news over the internet.

• nntp (network news transfer protocol)

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Recognizing Secure Sites

• Familiarity and accreditations

• Transport Layer Security (TLS)– Address bar has a padlock

• Site advisors

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Transport Layer Security (TLS): is a protocol whose purpose is to

protect data (ex: credit card info), between customer and online store

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• The secure version of http (port 443)

– Used in: e-commerce, e-mail, …

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Website reputation tools…

• … rates sites based on their safety.

• These tools alert users of a site’s potential to have viruses, malware, and of risk to have your identity stolen

• Examples:– Avast WebRep

– AVG LinkScanner

– Dr. Web LinkChecker

– McAfee SiteAdvisor

– Norton Safe Web

– Trend Micro TrendProtect

– MyWOT's Web of Trust

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Chrome browser – website rating alert

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mms://

• Microsoft's proprietary network streaming protocol

• mms (microsoft media server )

Sky News … TV

mms://live1.wm.skynews.servecast.net/skynews_wmlz_live300k/

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P2P (Peer-to-Peer)

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P2P

• Peer-to-Peer; it allows direct access, with permission, of a computer with another.

• …

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P2P

• Peer-to-Peer; it allows direct access, with permission, of a computer with another.

• Music files (or plain files) exchange…

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P2P - BitTorrent

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P2P

• Usually when you download a file from the internet, it works as follows:

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server

Web user

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P2P - BitTorrent

• However with the BitTorrent protocol utilized, downloading a file works as follows:

The idea is that in addition to the

server sending data to individuals

(clients /peers /you /user), the

individuals also share acquired data

with other individuals.

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P2P - BitTorrent

• Bit Torrent is just a basic set of rules and description of how to do things to help you and allow you to quickly download files as well as distribute the file being downloaded at the same time.

• In order to use a torrent file you must however, have a Bit Torrent client to download the torrent extension files.

• BitTorrent.com to get a bit-Torrent client

• These BitTorrent applications read files with a .torrent file extension…

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P2P vs BitTorrent…

P2P

• One to one

• P2P programs:– Kazaa

– Napster (original)

– Limewire

– WinMX

– …

BitTorrent

• One to many and many to one

• BitTorrent programs:– μTorrent

– Deluge

– Vuze

– …

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For more TORRENT RELATED info…

• http://www.tech-faq.com/download-torrent-files.shtml

• http://www.associatedcontent.com/article/477663/how_to_open_a_torrent_file.html

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What is Internet Relay Chat (IRC) protocol?

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What is Internet Relay Chat (IRC) protocol?

• An application that allows groups of users to communicate via messages on-line, using computers connected with the Internet.

IRC: First chat software

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What is IM ?

• Instant Messaging; exchange real-time typed messages or chat …….

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IM examples

• Instant Messaging; exchange real-time typed messages or chat …

– Google Talk

– MSN Messenger

– AOL Instant Messenger

– Yahoo Messenger

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Video Conferencing

• Real time transmission of audio and video that enables 2 or more people to have a meeting.

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What is freeware?

• Software that may be used for free but not sold

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Open Source

• Is software that provides its source code to everybody to use, modify and improve…

• …for free…

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Open Source – Examples…

http://en.wikipedia.org/wiki/List_of_open_source_software_packages

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What is shareware?

• Commerical Software distributed on a … “Try-Before–You-Buy” basis with limited functionality.

• Nagware – is a type of shareware that “nags” you to buy the software…

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What is a browser plug-in?

• Special software program, which extends a browser’s functionality.

• It can enable us to view or hear some multimedia files on the web, that would otherwise not be available by default.

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Plug-in Examples

• RealPlayer

• Adobe Acrobat Reader Portable Document Format (PDF)

• ShockWave player

• Active-X

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What is a cookie?

• Small text files that some web sites store (automatically) on your computer’s hard drive.

• The text files may contain personally identifiable information…

• Why? In order to recognize you (your computer) when you visit again their web site and to keep track of your visits.

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What is a cookie?

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Can you delete cookies?

• Internet Explorer 11…– Click the gear

– Safety

– Delete browsing history…

– Check-box next to Cookies…

– Click Delete

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Spam

• Spam is any message or posting, that is sent to multiple recipients who have not specifically requested the message.

• Other common terms for spam include:

1. Unsolicited commercial email (UCE),

2. Unsolicited bulk email (UBE)

3. Junk mail

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Spam

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What are “worms”, “viruses”?

• Worms and Viruses are malicious software programs that aim to harm your computer (software-hardware)

• Viruses

– Attaches self to program or file

– May spread via to other computer via network

– Can damage hardware software

• Worms– Spread from computer to computer unaided by human

action

– Infects email contact lists (ex. Outlook’s contact list)

– Can reduce computer network performance and/or stop responding

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Tips to guard computers?

• Don't open e-mail from an unknown source.

• Only open expected e-mail attachments.

• Don't automatically open e-mail attachments.

• Don't download programs from Web sites, unless you know and trust the source.

• Keep your anti-virus software updated!

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Trojan horse

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Trojan horse

• A program that appears to be performing a desired function, but is in fact performing something malicious…

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Anti-Spyware for Trojan horses

• Microsoft Windows Defender (www.microsoft.com)

• Malwarebytes' Anti-Malware (www.malwarebytes.org)

• Spybot Search & Destroy (www.safer-networking.org)

Free Software

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Phishing

• Is a method of fraudulently obtaining sensitive information, such as passwords, bank account, social security number, etc…

• Typically done through e-mail communication, where the e-mail seems legitimate, but it is not…

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Phishing @ MSU

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Phishing online…

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Pharming

• Receiving an e-mail with instructions to login to a web site that is fake, but you assume to be legitimate…

• This site will collect your login information… username & password

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Pharming-example

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Audio format … MP3

• MP3 is an audio compression algorithm

• It is also known as MPEG-1 Audio Layer-3

(MPEG = Moving Picture Experts Group)

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Other audio formats …

• WAV (Waveform Audio Format)

• WMA (Windows Media Audio)

• OGG (free open standard)

• FLAC (lossless)

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audio formats…

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Podcasts

• Personalized off-line audio web casts (non-music). For example audio broadcast, like a radio show.

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Examples …

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Key Logger … software

• A computer program that records every keystroke on a computer…

• To protect yourself … Use an anti-spyware program to remove (locate) unauthorized software and keystroke monitoring programs.

DISCLAIMER: Logging other people’s keystrokes, without their permission, can be considered illegal.

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Key logger software

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Firewall

• It is a software application used to block outside invaders

• Allows some packets to pass (in/out), blocking others.

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Firewall

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Firewall …

Firewall won’t protect you from viruses

It will protect you from intrusion attempts and internet worms

Firewall software are not perfect

Firewall access is allowed or blocked, by the firewall, through a computer’s network ports

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Check your network defenses…

1.https://www.grc.com/

2.http://security.symantec.com/sscv6/home.asp

3.http://www.auditmypc.com/

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For fun…

• Get to know your internet connection– Speed

• http://www.speakeasy.net/speedtest/• http://www.speedtest.net/

– IP Address• http://whatismyipaddress.com/ (click on Additional IP details)

Ping (Packet Internet Groper) is a networking tool:a tool to measure round trip time of a message sent from source to destination