CSCD 303Essential Computer SecuritySpring 2013

Lecture 11 – Internet Security

Reading: See links end of Lecture

Overview

• Internet Security• Threats• Web Technology• Web 2.0 • Active Content

– Javascript– Java Applets– ActiveX Controls– VBScript– Ajax

Internet Security

Major source of security problems is from the Internet

Going to study how the Internet works and the technologies used that both makes the Internet popular and unsafe at the same time

The way the Internet has evolved from storing content to user created content has contributed to the difficulty of keeping safe while we surf

Web Threats

Internet Threats 2009• 23,500 new infected Web pages are discovered every

day

– One every 3.6 seconds

• 15 new bogus anti-virus vendor websites discovered every day!!

– Number has tripled, up from average of five detected per day, during 2008

• 6,500 new spam-related websites are discovered every day

– One website every 13 seconds, 24 hours a day

– Almost double same period in 2008

http://www.sophos.com/sophos/.../sophos-security-threat-report-jul-2009-na-wpus.pdf

More Internet Statshttp://community.websense.com/blogs/websense-features/

archive/2009/09/15/websense-security-labs-report-state-of-internet-security-q1-q2-2009.aspx

• Today's threats are Web Based– During first half of 2009 Websense Security Labs

discovered:• 233% growth in number of malicious sites in last

six months and a 671% growth during last year• 77% of Web sites with malicious code are

legitimate sites that have been compromised.• 86% of all unwanted emails in circulation

contained links to spam sites and/or malicious Web sites

More Security Threats 2013

http://blog.spikes.com/blog/2013/1/11/the-top-security-threat-of-2013-is-the-web-browser

Recognition among security authorities that drive-by malware from web links is #1 threat facing networks today

Attackers are moving into targeting browser plugins such as Java, Adobe Reader and Adobe Flash.

Drive-by download attacks are almost exclusively launched through compromised legitimate websites which are used by attackers to host malicious links and actual malicious code

Web Technology

• Useful to understand how Web works– As technical people, have basic understanding

of clients/servers– Look at details and some stats on both browsers

and Web Servers– Which browsers would you guess are most

popular today?

Nice page of ALL Web browsers, even text basedhttp://www.webdevelopersnotes.com/design/

browsers_list.php3

Web Browser Stats

• Monthly statistics on Web Browser markethttp://www.w3schools.com/browsers/browsers_stats.asp

Ranking as of December 20121st - Chrome

2nd - Firefox

3rd – Internet Explorer

There are five major browsers used today Internet Explorer, Firefox, Safari, Chrome and Opera

Web Server Stats http://royal.pingdom.com/2011/09/16/microsoft-iis-web-

server-market-share-loss/

• Based on a survey of 205+ million sites, Netcraft reports that Apache has a 65% share in 2011 while IIS has 16%

Web Browser Functions

• Browser interprets and displays HTML files– Supposed to conform to specifications

maintained W3C (World Wide Web Consortium) organization• Standards organization for web

– Current Version HTML 4, Version 5 in progress http://www.w3.org/TR/html401/

– Current CSS Version 2, Version 3 in progress http://www.w3.org/TR/CSS2/, version 3 in

progress

Plug-ins Enhance Browsers• Visit web page that includes more than simple

HTML content

– Likely to need plug-in applications• Flash Player most needed plug-in

– 75% of the animated advertisements you see online are Flash .swf movies

• Adobe Acrobat Reader .pdf, next most needed– Most government forms, online application forms,

multitude of other documents use .pdf format on the Web

• Movie/audio player to run .mov, .mp3, .wav, .au, and .avi files

– Windows Media Player is .. most popular

Browser and Web Server State

• Neither Browsers or Web Servers keep “state”– What does this mean?

• How can browsers and Web Servers keep state?

Browsers and Web Server StateDefined This means user data is not persisted from

one Web page to next in a Web site Web developers refer to practice of tracking

users as maintaining state Series of interactions that a particular user

has with a site is a session

Browser State

• How do browsers keep state?– Cookies!!!

• Cookies, small text files stored in your computer's browser directory or other directory

• Cookies

– Created when you use your browser to visit a website that uses cookies to keep track of your movements within the site,

– Helps resume where you left off,

– Remembers registered login, theme selection, preferences, and other customization functions

Browser Cookies

• Two types of cookies are used• Session cookies,

– Temporary cookies remain in cookie file of your browser until you leave the site

– These cookies only stored in memory

• Persistent cookies,– Remain cookie file, browser for much longer

– Have an expiration date

Browser Cookies

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

Each cookie has values for six fields: * Name - Name of the cookie

* Value - ID string set by Web site

* Domain - Of Web site issuing cookie

* Path - “/” means the cookie is valid anywhere on that domain

* Expires - Cookie expires on that date

* Secure (used for cookies that require a SSL connection)

Example from my cookie stash ....

Evolution of Web Technologies

Problem

• All research shows, Internet based attacks appear to be increasing– Why is this?

Evolved from Web 1.0 to 2.0

Most people agree that Web 2.0 is– Interactive and social– Facilitating collaboration between

people This is distinct from the early web (Web 1.0)

which was a static information dump where people read websites but rarely interacted with them.

Web 2.0

• How do you define Web 2.0?– Web "as Platform," where software

applications built on Web as opposed to desktop

– Customers are building content• Activities of users generating

content ... ideas, text, videos, pictures create value to web site ...

• Nice YouTube Video of “Us as Web” http://www.youtube.com/watch?v=NLlGopyXT_g

Web 2.0 vs. Web 1.0

Web 2.0 Technologies

Web 2.0

• Web 1.0– Pull information– Read information– HTML (Web pages)

• Web 2.0– Push information– Read / write (cooperate and collaborate)– XML, RSS, Mash-ups– What's a mash-up?

Mash-up Defined

• A mashup– Web site that combines content data from more

than one source to create a new user experience.

– "mashup" comes from pop music term, refers to two or more songs combined into a new song

• Example– Most common Google product used for mashups

is Google Maps

Security and Web 2.0

• Why is Web 2.0 Insecure?– User generated content

• Do you trust your users?• Easier to upload or infect content

– More complicated technologies behind Web 2.0

• Active content – scripts and other automatic components

• Combined content from many sources– Advertising often contributes vulnerabilities

Web 2.0 Increases Threat

• Popularity of Web 2.0 sites has changed way we communicate and use web• Created an irresistible target for malware authors Social-networking sites, blogs, and wikis • Malware authors take advantage of these sites, opening up yet another front in cat-and-mouse game between security defenses and hackers

http://www.scmagazineus.com/ How-to-protect-against-Web-20-threats/article/34711/

Web 2.0 Nightmare

• “Every company has plans to move mission critical applications to the Web– Yet, companies do not have web

security plan to ensure applications free from exploits and hackers … (accidents waiting to happen)”

CIO Magazine quotehttp://cio20.com/2008/01/03/web-20-and-application-

security/

– Look at the technologies that enables Web to function

Web 3.0 is Coming

http://socialmediatoday.com/node/423732

Web 3.0 is a Marketing Term. Sadly, this is probably the most

likely way that we'll be using the term 'Web 3.0' in the future Within Web 3.0 social networks will be critical conduits through

which we design and stumble through our individual contexts, veering out to increasingly social content experiences built by big content providers like Yahoo, AOL, newspapers, blogs and so on

Amazon and eBay have already become large media experiences as we come to enjoy the act of browsing as much as the act of buying

– For example, eBay Motors says 95% of traffic doesn’t come to buy a car as much as look at cars. They’re a media channel that sells ads more than they are a marketplace for cars.

Active Content

Active Content

• Used to be Web pages consisted of HTML– Purpose of the Internet was

• Downloading information • Viewing pictures and other graphic

images• Filling out input forms

• Our Web site, example of what kind of content?

http://penguin.ewu.edu/cscd303/

Active Content

• What is active content?• Web site that is either interactive

– Such as Internet polls or– Dynamic, such as animated GIFs, stock tickers,

weather maps, moving ads– Embedded objects, streaming video and audio

ABC http://abc.go.com/

Active Content Languages

• Implementing Active Content– HTML does not have built in capability to

handle active content• Embedded video objects, • Dancing bears

– Other languages added to Web pages within HTML tags allow expanded capability

– What languages implement Active Content?

Active Content Languages

• Active content implemented mainly through– Javascript– ActiveX Controls– Java Applets– VBScript– AJAX

Javascript

• What is it? Has anything to do with Java?– JavaScript, is unrelated to Java

programming language• Has common C syntax• JavaScript copies many Java names and naming conventions

– Was originally named "LiveScript" • Renamed in a co-marketing deal between Netscape and Sun• Netscape bundling Sun's Java runtime in their then-dominant browser

Javascript

JavaScript writes functions that are embedded in or included from HTML page

Simple Examples– Opening or popping up new window with

control over the size, position, and attributes of window

– Validation of web form input value before submitted to server

– Changing images as mouse cursor moves over them … catches user’s attention

– Example herehttp://www.javascripter.net/faq/

onmouseo.htm

Javascript

• JavaScript code runs locally in user's browser– Respond to user actions quickly, making

an application feel more responsive– Example:

• Gmail is written in JavaScript– JavaScript dispatches requests for

information such as the content of an e-mail message

HTML code with Javascript<html> <head><title>simple page</title></head> <body> <script type="text/javascript"> document.write ('Hello World!'); </script> <noscript> <p>Your browser either does not support JavaScript, or you have JavaScript turned off.</p> </noscript> </body> </html>

Java Applets• Java Applets

– The word applet is meant to suggest a small application

– Applets were intended to be small programs run over the Internet• Applets can be viewed over Internet,

or without any connection to Internet• When you use browser to view page

that contains an applet, applet's code is transferred to your system

• Executed by browser's Java Virtual Machine (JVM)

Java Applets

• An applet class is compiled in same way as any other Java class– However, applets run differently from

other Java programs

• Normal way to run applet is to embed it in an HTML document– Then run and viewed through a Web

browser

Java Applets

<html><head><title>Vampire Control</title></head>. . .<applet code="AppletCalculator.class" width=400

height=300></applet> . . .</html>

Active X

• ActiveX, set of object-oriented programming technologies and tools from Microsoft! • You create, in ActiveX environment, a component–Self-sufficient program that can be run anywhere in your ActiveX network –Component known as an ActiveX control–ActiveX Microsoft's answer to Java

• An ActiveX control is like Java applet–Can be developed in several languages

•Visual Basic,• C++• Java

Active X

• ActiveX• Renamed Component Object Model (COM) developed by Microsoft for Windows,• Changed to ActiveX in 1996

• A software application can compose one or more components in order to provide needed functionality

Active X

• Most Microsoft Windows applications– Internet Explorer, Microsoft Office, Microsoft

Visual Studio, Windows Media Player,– All … Use ActiveX controls

• Encapsulate functionality as ActiveX controls

can be embedded in other applications • Internet Explorer also allows ActiveX controls to be

embedded inside web pages• Point for us, • Can expand application functionality to the

Web!

Example Active X Control

Active X

• ActiveX controls are like Java applets,• Both designed to be downloaded and executed from web browsers• Differences

• Java applets can run on nearly any platform,• ActiveX components can only run on Microsoft's Internet Explorer

• ActiveX controls also granted a much higher level of control over Windows than Java applets• Making them both more powerful and dangerous!!!

Active X Example• The process of embedding ActiveX controls into a web page is very similar to the way Java

applets are embedded. The following example shows the HTML code used to embed an ActiveX control.

• <OBJECT ID="AreaMenu" WIDTH=192 HEIGHT=192• CLASSID="CLSID:275E2FE0-7486-11D0-89D6-00A0C90C9B67" • CODEBASE="http://activex.microsoft.com/controls/mcsi/mcsimenu.cab#• version=1,0,0,44">• <PARAM NAME="ForeColor" VALUE="&H00000000">• <PARAM NAME="BackColor" VALUE="&H00BEBEBE">• <PARAM NAME="FontName" VALUE="Verdana">• <PARAM NAME="FontSize" VALUE="10">• <PARAM NAME="FontBold" VALUE="0">• <PARAM NAME="FontItalic" VALUE="0">• <PARAM NAME="FontUnderline" VALUE="0">• <PARAM NAME="FontStrikethrough" VALUE="0">• <PARAM NAME="FontCharset" VALUE="0">• </OBJECT>

Active X Example• The tag creates the ActiveX object. The tag has 5 attributes:

– ID: Object Name. You use ID to refer to the object with JavaScript

– WIDTH: defines the width of the control on the web page – HEIGHT: defines the height of the control on the web page – CLASSID: Each ActiveX control assigned unique Class ID

number, like an identification number, use number to tell computer which ActiveX control to load

– CODEBASE: If control is not present on system, Codebase attribute tells the browser where to find the control on the Internet. The viewer's browser will then download the file and install it on to the user's computer

– Short article below explains Active X

http://www.cs.ualberta.ca/~zaiane/courses/cmput499/work/presentations/activex.html

VBScript

• VBScript– Visual Basic Scripting Edition– An Active Scripting language developed

by Microsoft– Language's syntax reflects its history as

a limited variation of Microsoft's Visual Basic programming language

VBScript

• VBScript installed by default in every desktop release of Microsoft Windows since Windows 98

• Microsoft Internet Explorer• VBScript is similar in function to

JavaScript, as a language to write functions that are embedded in or included from HTML pages

VBScript

• Web browsers Firefox, and Opera do not have built-in support for VBScript• So ... developers almost always use JavaScript for cross-browser compatibility

• Besides client-side web development,• VBScript is used for server-side processing

of web pages, most notably with Microsoft Active Server Pages (ASP)

VBScript Example

<html><body><script type="text/vbscript">document.write("Hello World")</script></body></html>

Can you see this in Firefox?

Ajax

• AJAX– Group of web technologies– Implements a web application that

communicates with a server in the background,

– Without interfering with the current state of the page

• AJAX = Asynchronous JavaScript and XML• AJAX is based on JavaScript and HTTP requests• Not a new language but a combination of

languages already known

Ajax

Traditional Web application, interactionbetween customer and server goes like this

1. Customer accesses Web application 2. Server processes request and sends data to browser while the customer waits 3. Customer clicks on a link or interacts with the

application 4. Server processes request and sends data back to the browser while customer waits 5. etc....

• There is a lot of customer waiting!!

Ajax

• Ajax Acts as an Intermediary• Ajax engine works within Web browser to render Web

application and handle any requests that customer might have of Web server

• At start of session, browser loads an Ajax Engine — written in JavaScript and usually tucked away in a hidden frame– Engine is responsible for both rendering interface

user sees and communicating with server on user’s behalf

Ajax vs Traditional Web Browser

Ajax• With Ajax,

– JavaScript loaded when page loads handles most of basic tasks

– Data validation and manipulation, – Plus displays changes ... without a trip to

server!!• Same time that it makes display changes for

customer, sends data back and forth to server– Data transfer is not dependent upon actions

of customer– Google maps,– Google suggest,– Flicr use Ajax

• http://adaptivepath.com/ideas/essays/archives/000385.php

Summary

• Begun to look at Internet and Web security

• Web 2.0 is a problem• Active Content is today’s Internet• People want functionality• Security seems to be secondary• So, what else is new?

References

• Nice Overview of Browser/Web Workingshttp://taligarsiel.com/Projects/howbrowserswork1.htm

• Wikipedia Browser Comparison Pagehttp://en.wikipedia.org/wiki/Comparison_of_web_browsers

• Browser Cookieshttp://www.timeatlas.com/term_to_learn/general/

browser_cookie_basics

http://www.morevisibility.com/analyticsblog/from-__utma-to-__utmz-google-analytics-cookies.html

• Web 2.0http://en.wikipedia.org/wiki/Web_2

The End

• Next Time more Internet Security