Network Security Demo: Web browser
Email Messages An email message can be instantly forwarded around the globe, even if accidentally. Do not write anything in a message that you will later regret! Read over the message before you send it! Email messages can carry dangerous attachments. Do not open any file attached to a message unless you are absolutely certain of the sender of the message and the safety of the attachment. Best rule: Don t open it unless you were expecting it.
Viruses & Trojan Horses Viruses and trojan horses are programs designed to replicate themselves as they pass from computer to computer - and usually do harm! They are usually passed by a user opening an infected attachment. Don t do that! You should have a good antivirus program on your home computer and keep it up-to-date on the latest viruses. You can run the University s antivirus program to check your home directory and floppy disks for viruses, and to disinfect them if some are found.
Viruses & Trojan Horses (cont d) Real viruses are reported at a number of sites: Symantec.com Viruses & Risks http://www.symantec.com McAfee.com Threat Center http://www.mcafee.com
Hoax Viruses Hoax virus warnings are frequently sent by email, and unknowing users forward them to all of their friends. Two known factors make a successful virus hoax: (1) technical sounding language, and (2) credibility by association, in that the warning appears to come from a knowledgeable person. If you get such a warning, check it out thoroughly before forwarding to anyone.
Internet Hoaxes Hoax viruses (and other myths and urban legends) are reported at several sites: Urban Legends and Folklore - http://urbanlegends.about.com/ Symantec Antivirus Research Center - http://www.symantec.com/avcenter/hoax.html Truth or Fiction - http://www.truthorfiction.com and several others
Chain Email Chain email letters are related to hoax virus warnings in that they often spread false information, and they ask to be forwarded to all of your friends. You should NOT forward chain letters. Forwarding chain letters of any type is a violation of the acceptable use policy at UH (and at most, if not all, Internet Service Providers). Check those same Internet Hoaxes sites for information on these.
Web Bugs A web bug is an object usually an invisible image that is embedded in a web page or e-mail and allows checking that a user has viewed the page or e-mail. If in an email, when the image is loaded, the request to the remote server to get the images tells the server you have read the message the email address is a good one. =>Disable automatic image display in email If in a web page, the image is usually loaded from an advertiser s server, not the server from which the page was loaded, so that the advertiser can track your browsing. =>Disable images from remote servers in browser
Block remote images in email Example: Thunderbird
Block remote images in browser Example: Firefox
Cookies An HTTP cookie is text sent by a server to a web browser and then sent back unchanged by the browser each time it accesses that server. During a session, cookies are used for maintaining specific information about users, such as the contents of electronic shopping carts. (good!) Third-party cookies: If an advertising image is retrieved from a remote (third party) server other than that of the original web page, that remote server can maintain a cookie a tracking cookie that follows your tracks between web sites. (not so good) => Disable third-party cookies in browser.
Block third-party cookies in browser Example: Firefox
Phishing Phishing attempts to fraudulently acquire sensitive information, such as passwords and credit card details, by masquerading as a trustworthy person or business in an email or instant message. The user is told to verify your account and is provided a link to click on for doing so. But the text containing the link does not match the link itself, which actually directs the user to an authentic-looking faked web site to login with username and password!
Phishing (cont d) For example, the text might look like this: https://service.capitalone.com/... but the actual link behind the text might be: http://www.capitalone0.go.ro/onlinebanking.capitalone. com/capitalone/index.html =>Don t click on that link! Demo: Show how mousing over link text in browser or email message reveals the true link underneath it.
Remote images are hidden apparent link actual link
Spam Spamming is the abuse of electronic messaging systems to send unsolicited, bulk messages. Email is the most recognized form, but spam also targets instant messaging, blogs, chat rooms, etc. Although all types of unwanted messages chain email, viruses, phishing attempts could be considered spam, the term is most commonly attributed to unsolicited advertising. Your most important defenses against spam are protection of your email address and use of a spam filter.
Security Tips Make your passwords hard to guess, change frequently. Disable remote images in email and browser. Disable third-party cookies in your browser. Use a firewall. Use anti-virus software. (McAfee) Use adware and spyware detectors. (Ad-Aware, Spybot) Keep all software patched up-to-date. (Windows Update) Don t open unexpected attachments. Don t click on phishing links. Use an email spam filter. Protect your email address. http://www.networksolutions.com/online-security/securitytips-articles.jsp
Web Security