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PORTIA Project 1 Mitigating Online ID Theft: Phishing and Spyware Students:Blake Ross, Collin Jackson, Nick Miyake, Yuka Teraguchi, Robert Ladesma, Andrew Morrison Faculty:Dan Boneh and John Mitchell Special thanks to the SF-ECTF and SS.
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2 Sample phishing email
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3 Sample phishing site http://202.69.39.30/snkee/....
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4 Magnitude of problem u Fastest growing crime on the Internet. u Trends: keyloggers from phishing sites. http://www.antiphishing.org 2004-5MarFebJan…JulyJan spoofs/ month 287026862602…1634113 # targets786864…137 March, 05: 80% at 8 brands, average uptime 5.8 days, 81% of targets are financial
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5 What can we do about phishing? u Spam filter: Phishing starts with email, so stop it there. Non-trivial: phishing emails look like ordinary email. u Client-side methods: Anti-phishing using browser plug-ins. Anti-spyware using Virtual Machine Monitors. u Server-side methods: Personalized web pages. Improved user authentication (e.g. tokens or certs ).
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6 PORTIA ID Protection Work u Long term effort to develop online ID protection tools. SpoofGuard : (NDSS ’04) Alerts user when browser is viewing a spoofed web page. Uses variety of heuristics to identify spoof pages. A new type of anomaly detection problem. PwdHash : (Usenix Sec ’05) Simple mechanism for strengthening password web auth. SpyBlock : (under development) A Virtual Machine (VM) approach to SpyWare defense.
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PORTIA Project 7 1. SpoofGuard: Detect Phishing Web Sites http://crypto.stanford.edu/SpoofGuard
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8 SpoofGuard Browser Plug-in u Compute spoof index: Weighted sum of several spoof measures Depends on current page and browsing history u Provides two forms of information: Passive alerts in toolbar. Active blocking when necessary. u Challenges: Must be easy for novice users. Detect malicious pages yet minimize false alarms.
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9 Sample Heuristics u History Check: Site is assumed OK if in user’s history list. u Domain Check: Check similarity to domain in history list. u Email Check: Suspicious if page is reached by following email link u Impact: Ebay toolbar, Yahoo ! toolbar, WholeSecure Multiple requests for Firefox support.
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10 Current/future work u SpamAssassin extensions: Download pages that URL’s in incoming email point to. Run SpoofGuard heuristics on downloaded pages. u Spam archive scanning: Automatic detection of new phishing sites. www.spamarchive.org
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PORTIA Project 11 2. PwdHash: Improved Pwd Mgmt http://crypto.stanford.edu/PwdHash
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12 Strengthen Web Pwd Auth Current web auth: cleartext password over SSL Vulnerable to phishing. Vulnerable to break-ins at low security sites. Simple improvement: Browser plug-in that converts a user’s pwd into a unique pwd per site: 1. Locate all pwd HTML elements on page: 2. When form is submitted replace all pwd’s by: PRF pwd (domain-name) 3. Phishing site only sees hash of Ebay password. The challenge: Extremely hard to implement securely in a modern browser!
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13 PwdHash Challenges 1.Javascript attacks 2.Pwd reset after plug-in install 3.Dictionary attacks (sol: EKE or SFE for equality test) 4.What salt to use in hash? 5.How to encode resulting hash? 6.Internet Café u Our design goal: transparent to user. u Impact:1. Google: PhD intern. 2. TIPPI working group: MS, Mozilla, RSA
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14 Javascript attacks u Phishing site can create Javascript to steal user’s unhashed password. Record all key-strokes sent to page Change target-domain-name on submit Mask regular text field as a password field
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15 Javascript attacks (cont.) u Defense 1: Password prefix / Password key Ask user to start all passwords with “@@” Plus-in traps all keyboard events to window. When “@@” detected, replace subseq. keys with ‘%’ –Browser never sees pwd. On ‘BeforeNavigate2’ event, replace ‘%%’ in POST data with hashed pwd. Alert user if “@@” detected in key stream while focus not on pwd field.
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16 Pwd Salting – an old idea u Hash pwd with realm provided by remote site: HTTP 1.1 Digest Authentication Kerberos 5 u Hash pwd with network service name: Gabber, Gibbons, Mattias, Mayer [FC ’97]. Proxy. Abadi, Bharat, Marais [PTO ’97] u Challenge:implementing securely in a modern browser.
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PORTIA Project 17 SpyBlock Spyware defense tool Current work
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18 SpyBlock design u Proxy VM keeps sensitive user info away from SpyWare. u User hits pwdkey before and after typing sensitive info. VMWare ACE Server / Xen Guest OS Firefox Proxy VM SpyWare apps https page PwdKey Keys Junk https junk data
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19 Summary u Long term effort focused on ID protection tools. u Current tools: SpoofGuard, PwdHash, Current/future work:SpyBlock u Strong focus on technology transfer: Interns help do tech transfer. Source code available on PORTIA web site. Close collaboration with SF-ECTF.
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