Hack Firefox to steal web-secrets Sunil Arora

How many of you use Firefox ?

Firefox and extensions Firefox  Claimed to be most secure and most efficient web browser Firefox extensions  A way to extend Firefox to customize or add more functionality to it  Most of the popular websites (Google, Stumbleupon, Facebook etc.) provide their toolbar in form of extension  Popular functionalities like FTP, CHMReader, Flashblock, Adblock etc are available in form extensions

Agenda Malware overview Malware – How it works A look at existing vulnerabilities How malware can find its way on to victim’s Firefox Live demo

Lets meet john Uses internet for social networking. For example Facebook, orkut, myspace etc. Uses for professional as well as personal communication. For ex. Gmail, Yahoo or Corporate web Uses internet for his credit card transactions. For ex. Citibank, ICICI bank, HSBC etc Uses internet banking for managing his day to day finance activity Blogs on internet for professional as well as personal purpose.

John’s online world Problem Statement How to retrieve values of elements like username, password, credit card number, IPIN etc for a particular web resource (Gmail /Yahoo/Banking website etc)

Malware -Architecture Target List Secret List Secret Collector Engine Communicator Module Our Malware is nothing but a malicious Firefox extension

Intercept http requests being made by the browser Malware - Secret Collector -I Normal http request process Parse http request And Retrieve user typed Web secrets

Malware - Secret Collector - II Different Components within the Firefox can register to send/receive notifications. Some standard notifications --  quit-application  memory-pressure  Domwindowopened / domwindowclosed  http-on-modify-request / http-on-examine- response How to intercept http request ??? “Notifications” mechanism in Firefox

Malware -Target List Set of websites we want to steal secrets for URL: Number of attributes: 2 Attribute Names: , Passwd

Malware - Secret List Set of collected secrets URL: Number of attributes: 2 Name: , Name:Passwd Value:helloworld

Communicator Module Target ListSecret List Internet

How it can find its way to john’s Firefox - I Installing malicious extension  Command line silent install (firefox.exe – install –silent …XXX)  Using Firefox’s extension installation wizard  Copy malicious extension’s file in extension directory of Firefox

Exploit FireFox’s vulnerability (For ex. Extension upgrade vulnerability, quicktime RSTP vulnerability) to push the extension Installing the malicious extension exploiting vulnerability in some other existing application Bundle it in some other popular extension and redistribute Host malicious extension on a webserver and craft a webpage to drive user to install the hosted extension How it can find its way to john’s FireFox - II

Firefox extension upgrade vulnerability Firefox upgrade mechanism  enabling the extensions to poll an Internet server for updates  If an update is available, the extension will typically ask the user if they wish to upgrade, and then will download and install the new code.  Extensions fetching update from a (non-SSL webserver) instead of (SSL enabled webserver) are vulnerable to DNS based man in the middle attack.

Facebook Extension Facebook is a very popular social network site. It provides a FF toolbar as an FF extension. Any FF with facebook toolbar (v 1.1) is vulnerable to update vulnerability. Package our malicious extension in existing facebook toolbar (v1.6) and will push it through the update vulnerability Once malicious extension is installed in FF. The victim’s FF is compromised.

Attack Flow Facebook extension update Server Attacker’s update Server Hosting malicious extension Untrusted public network John’s FF running Facebook extensionHacker running Master Server X Y What is IP of update server Update server is at Y Fetches Target Lists Sends collected Secrets

Advisory Do not use public computer for important information exchange Up-to-date Software Install Firefox extensions from authentic sources ( only Regularly check list of installed extensions Observe Firefox’s performance. Anomaly in performance may be due to an unwanted extension Do not ignore extension install warning

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