Upload
peterbuck
View
872
Download
5
Tags:
Embed Size (px)
DESCRIPTION
Citation preview
Safe(r) Web Browsing
IT Security RoundtableApril 9, 2010
Harvard TownsendChief Information Security [email protected]
Agenda
“The Internet is a bad neighborhood.”The dangers of web browsingHelpful features built into web browsersTools you can add to your web browsersTrend Micro is your friendMisc. cautions/tips/tricksQ&A
2
The Risks Computer infected with malicious software
(malware) Stolen, altered, and/or deleted K-State or
personal information (do you have SSNs on your computer?)
Identity theft Financial fraud – stolen credit card and/or bank
account information Your computer is used to send spam Your computer stops working because of damage
done by the malware Your computer is used to infect other computers Your computer’s network access is blocked by
the security team to prevent further damage 3
Malicious links/sites – to click or not to click, that is the question.
Malicious advertisements Drive-by Download (don’t even have to
click!) Search engines tricked to present
malicious/bogus result near the top of your search results (aka Blackhat Search Engine Optimization (SEO) Poisoning)
4
The Threats
5
Real K-State Federal Credit Unionweb site
Fake K-State Federal Credit Unionweb site used in spear phishing scam
6
Spear phishing scam received by K-Staters in January 2010
7
The malicious link in the email took you to an exact replicaof K-State’s single sign-on web page hosted on a server in the Netherlands
which will steal your eID and password if you enter it and “Sign in”.Note the URL highlighted in red – “flushandfloose.nl”, which is obviously
not k-state.edu
8
Real SSOweb page
Fake SSOweb page
9
Real SSOweb page –note “https”
Fake SSOweb page –
site not secure (http,
not https) andhosted in theNetherlands
(.nl)
Can I click on this? Watch for displayed URL (web address) that does
not match the actualdisplayed: http://update.microsoft.com/microsoftupdate actual: http://64.208.28.197/ldr.exe
Beware of link that executes a program (like ldr.exe above)
Avoid numeric IP addresses in the URLhttp://168.234.153.90/include/index.html
Some even use hexadecimal notation for the IP:http://0xca.0x27.0x30.0xdd/www.irs.gov/
Watch for legitimate domain names embedded in an illegitimate onehttp://leogarciamusic.com/servicing.capitalone.com/c1/login.aspx/
10
Can I click on this?
Beware of email supposedly from US companies with URLs that point to a non-US domain (Kyrgyzstan in example below)From: Capital One bank <[email protected]>URL in msg body: http://towernet.capitalonebank.com.mj.org.kg/onlineform/
IE8 highlights the actual domain name to help you identify the true source. Here’s one from an IRS scam email that’s actually hosted in Pakistan:
11
Can I click on this?
Beware of domains from unexpected foreign countries Kyrgyzstan: http://towernet.capitalonebank.com.mj.org.kg/onlineform/Pakistan: http://static-host202-61-52-42.link.net.pk/IRS.gov/refunds.phpLithuania: http://kateka.lt/~galaxy/card.exeHungary: http://mail.grosz.hu/walmart/survey/Romania: http://www.hostinglinux.ro/Russia: http://mpo3do.chat.ru/thanks.html
MANY scams originate in China (country code = .cn)
Country code definitions available at: www.iana.org/domains/root/db/index.html
12
Can I click on this?
Analyze web links w/o clicking on them by copying the URL and testing them at these sites: Trend Micro’s Web reputation query –
reclassify.wrs.trendmicro.com/wrsonlinequery.aspx McAfee SiteAdvisor (enter URL on this web
page – you don’t have to install their software):www.siteadvisor.com/
13
Can I click on this?
Watch for malicious URLs cloaked by URL shortening services like: TinyURL.com Bit.ly CloakedLink.com
14
Can I click on this?
TinyURL has a nice “preview” feature that allows you to see the real URL before going to the site. See tinyurl.com/preview.php to enable it in your browser (it sets a cookie)
Bit.ly has a Firefox add-on to preview shortened links: addons.mozilla.org/en-US/firefox/addon/10297 It also warns you if the site appears to be malicious:
15
Can I click on this?
16
Malicious Advertisements
Major ad networks (aka “ad aggregators”) affiliated with Google (e.g. Doubleclick.com), Yahoo (yieldmanager.com), Fox and others, covering more than 50% of online ads, have been infiltrated with “poisoned ads” containing malicious code (Source: Avast!)
Happened to the New York Times website last fall 17
NY Times incident Ad placed via phone call from person posing as
Vonage, an intl phone company and regular advertiser on NY Times web site
Since Vonage well known, they allowed ads to be served by remote 3rd party host (i.e., not the NY Times web server)
Legitimate Vonage ads displayed all week During the weekend, legitimate
ad switched to a malicious onethat served up fake antivirusscareware which tried to getpeople to buy bogus securitysoftware with a credit card
18
Malicious Advertisements Isn’t just NY Times…
ratemyprofessors.com (!!) msnbc.msn.com health.msn.com music.msn.com astrology.msn.com realestate.msn.com usatoday.com cnbc.com digg.com mail.live.com addictinggames.com foxsports.com hollywoodreporter.com
These legitimate sites are not in cahoots with the criminals, they’re just not careful enough in screening ads from third party ad networks 19
Drive-by Downloads
The scary thing is you don’t even have to click on anything – just visiting a site with malicious code can initiate a download that installs malware on your computer without you knowing it.
Symantec claims every one of the top 100 websites in the world have served up malicious code at some point
JavaScript in the ad executes when the page is loaded and tries to exploit a vulnerability in Adobe PDF reader, Java, or Flash… or all three; this is why a tool like NoScript or something that blocks ads is effective 20
Drive-by Downloads
Commonly used to promote fake antivirus software (aka “scareware” or “extortionware”) – make you believe your computer is infected with lots of malware, enticing the nervous user to “Click Here” to buy fake security software for $30-$100, plus they steal your credit card information
Can be used to infect your computer with any malware – keyloggers, Trojans, Torpig, …
Malware changes at a very rapid rate to escape detection by AV software; hackers test their malware against 40 popular AV products at virustotal.com before launching 21
Search EnginePoisoning Search engines, like Google, are tricked into
presenting a malicious link in the top 10 results for popular searches
Known as “Blackhat Search Engine Optimization (SEO) Poisoning”
13% of Google searches for popular or trendy topics yield malicious links
Currently used mostly for fake antivirus scams Exploit current events, popular topics
January 2010 an all-time high with hackers capitalizing on Haitian earthquake, release of movie Avatar, and announcement of the iPad
22
Blackhat SEOPoisoning
23
Search for“Oscars 2010 winners”
Source: Sophos security blog March 8, 2010
Malicious pagesthat infect withFakeAV scareware
Blackhat SEOPoisoning
Examples of exploited topics in 2010: Tiger Woods car wreck, affairs Death of Patrick Swayze Affair of Sandra Bullock’s husband with Michelle “Bombshell”
McGee Rumored death of Bill Cosby (pretty common to make up a
sensational hoax) Chilean earthquake Moscow subway explosions Plane crashing into IRS building in Austin, TX Sea World killer whale attack Sentencing of TJX hacker Oscars Kids’ Choice Awards Olympics (esp. death of Georigian luge athlete) March Madness basketball tournament April Fools Day (a natural…)
24
Blackhat SEOPoisoning
How does it work? Legitimate web server compromised (often due to
a vulnerability in a content management system) and SEO poisoning code loaded (usually a PHP script)
When the PHP script determines a search engine “crawler” (Google, Bing, MSN, Yahoo, AOL, etc.) is making the request for the web page, it returns content filled with lots of info appropriate for the event it’s trying to mimic (keywords, phrases, other high-ranking URLs about the event, images and videos copied high-ranking sites)
They’ll also harvest search engine results to extract popular phrases used to search hot topics (ie, they let the search engines do the research for them!)
25
Blackhat SEOPoisoning
How does it work? When PHP code determines it is a user, not a
search engine, visiting the site, it redirects them to a malicious site to try to infect their computer or just pop-up bogus security warnings and try to get them to buy the fake antivirus software (i.e., you’re not always infected when you’re tricked into clicking on the link)
The redirection domain name can change as often as every 10 minutes, based on instructions from a “command & control” server making it harder to identify
26
Blackhat SEOPoisoning
How do I prevent it? Be paranoid – think before you click! Pay attention to the link – only visit reputable sites Pay attention to warnings from anti-phishing filters,
Trend Micro WRS, andother tools you might use to detect malicious links (see later slides)
If you click on a search result and security warnings like this pop-up, do NOTclick on anything – contactyour IT support person
27
Blackhat SEOPoisoning
How do I prevent it? Run antivirus software and keep it up-to-date
(required to use Trend Micro on campus) Keep ALL software patched, including the
web browsers and plug-ins, Adobe products, Flash, and Java VERY challenging for IT staff, let alone your
average user Recent study found that average home user would
have to patch 75 times per year (once every 5 days!) using 22 different patching mechanisms
28
What’s a feller to do?
If you’re not scared by now, then I’m worried about you and I pity your IT support person
29
Browser features – IE8 Domain highlighting
SmartScreen filtering – block access to malicious sites and file downloads
30
Browser features – IE8 Pop-up blocker- if it
causes a problem with an application, add a specific exception; don’t turn off the pop-up blocker
If you don’t see a malicious pop-up message, you won’t be duped by it.
31
Browser features – IE8 InPrivate Browsing – good if using a
public computer in a lab or Internet Café since it leaves no trace of your browsing activity. The cache (“temporary Internet files” which are local copies of content from web sites you visited recently), cookies, and browser history (web address of sites you visited recently) are not stored.
32
Browser features - Firefox
Anti-phishing and anti-malware protection – detects and blocks access to known malicious sites and downloads
33
Browser features - Firefox
Pop-up Blocker Similar to IE; add exceptions at
Tools->Options->Content Private browsing – cache, cookies, and
history not saved, just like “InPrivate Browsing” in IE
Instant Website ID – provides detailed identity information, if available, about the site:
34
Browser add-ons
NoScript from noscript.net Extension for Firefox (not available for IE) Prevents execution of JavaScript, Java, and
Flash – the most common culprits for web-based attacks
Can selectively allow trusted sites Often able to view content of interest without
enabling all scripts – you don’t need to see the ads or that cute Flash animation!
Takes some getting used to and it takes a while to build up the exceptions for trusted sites so it’s not always getting in the way of your productive use of the web
35
Browser add-onsWeb of Trust from www.mywot.com Available for Firefox,
IE, Google Chrome Rates web sites on
Trustworthiness Vendor reliability Privacy Child safety
Warns you if about to visit a poorly rated site Tags ratings in Google search results, which is really
helpful for detecting Blackhat SEO Poisoning Also tags links in web-based email like K-State’s Zimbra
Webmail and Gmail Provides user comments about the site and its rating
36
Browser add-ons
Adblock Plus from adblockplus.org Again, only for Firefox (IE is not nearly as
extensible as Firefox!) I haven’t used this tool but others have
recommended it for blocking advertisements
Some have argued against blocking ads since they provide the revenue that allows so much free content on the web
37
Help from Trend Micro
Web Reputation Services (WRS) Blocks access to known disreputable
sites Enabled in both Windows and Mac
versions K-State IT security team regularly reports
new malicious links to Trend to add to the block list
Also provides traditional “antivirus” malware protection
38
Trend Micro WRS isyour friend
39
Recognizing FakeAntivirus Alerts
Actual pop-up alert from Trend Micro OfficeScan:
40
Recognizing FakeAntivirus Alerts
Example of a Fake AV “scareware” alert that tries trick you into buying worthless software to fix a non-existent infections:
41
Misc. Tips/Tricks
Use a Mac Firefox vs. Internet Explorer (IE)?
Both have vulnerabilities Both have helpful security features ActiveX in IE historically been a security concern but is less of a
target these days If you use IE6 or IE7, upgrade to IE8 because of significant
security improvements plus application compatibility Stay away from questionable sites
Pornography Gambling Some gaming sites
Peer-to-peer file sharing applications are dangerous since they too have been infiltrated with malware; the movie you download may also have malware attached to it that will infect your computer when you try to run the movie.
42
Misc. Tips/Tricks“… because that’s where the money is.” Willie Sutton, famous 19th century bank robber on why he robs banksBeware of where you do your online banking – cybercriminals are actively hunting you online and targeting your computer because “that’s where the money is”49 instances of Torpig malware at K-State thus far in 2010, 34 in 2009 – steals username/passwords and banking infoThe American Bankers Association recommends using a dedicated computer for online banking since malware typically gets on a computer via web surfing or emailA low-end $500 PC or netbook good for this, or re-purpose the old computer when you upgradeMake sure your banking computer is protected with a strong passwordAt the very least, don’t do online banking on the same home computer your children (and their friends) use!
43
Misc. Tips/Tricks
Risks of social network sites People tend to reveal too much personal
information Pay careful attention to the security
configurations, esp. for privacy Beware of third party applications and
advertisements Beware of unusual friend requests
Application whitelisting (specify the programs that can run on the computer – everything else is prohibited)
44
Misc. Tips/Tricks Remove administrator rights from users Recent study of 2009 Microsoft security vulnerabilities claims
removing administrator rights would prevent exploitation of: 90% of the “critical” vulnerabilities found in Windows 7 100% of the 55 vulnerabilities found in Microsoft Office 100% of Internet Explorer 8 vulnerabilities 94% of the vulnerabilities in all versions of IE 81% of all critical vulnerabilities announced/patched by Microsoft
in 2009 With admin privileges, hacker can:
Install or remove/disable any software Change security settings, disable AV software Create new accounts View/copy/change/delete all files Have complete control of the computer
Running as a regular user limits the damage to that user’s account
Create a separate regular user account for your children on your home computer(s)!!
45
Misc. Tips/Tricks
Don’t let your browser store/remember important passwords like: eID Financial accounts
38% of bank account or username/password information stolen by Torpig malware came from the browser’s password store on the compromised computer
Password-protect the browser password store
46
Misc. Tips/Tricks
Don’t keep yourself logged into important accounts
Similar to letting the browserstore username/password;effect is the same – anyonewith access to the computerhas access to those accounts
Never do either on a public computer47
Misc. Tips/Tricks Use a password manager
Windows: Password Safe - pwsafe.org Many useful features, easy to use
Macs: Password Gorilla - www.fpx.de/fp/Software/Gorilla/ Also available for Windows and Linux Can read Password Safe database
Multi-OS and multi-computer: LastPass - lastpass.com Passwords stored on server so can access them
from multiple computers Premium version @ $1/month provides mobile
device support (iPhone, Blackberry, Android, etc.), no ads, and multi-factor authN support 48
Conclusion
There’s no way to be 100% secure surfing the web these days
Use multi-faceted approach to reduce your risk (browser security features, browser add-ons, Trend Micro security software, educate yourself)
These tools and techniques make your browsing experience less convenient and may frustrate you at times, but they are necessary in today’s hostile online climate
Think before you click!
49
What’s on your mind?
50