Abstract: A system and method for preventing propagation of malicious content associated with an electronic message are disclosed. An electronic message and content associated with the electronic message is simulated in a virtual machine which emulates the destination computing device of the electronic message. A virtual firewall receives one or more commands as the electronic message or content associated with an electronic message is executed. Initially, the virtual firewall establishes a network connection and determines the type of action associated with the commands. If the type of action comprises a connection maintenance or configuration command, the network connection is maintained. If the type of action comprises a data transmission command, the network connection is terminated. This allows the virtual machine to simulate performance of a networked computer by transmitting a subset of the data through a network connection.

Abstract: A system and a method for detecting malicious content associated with an electronic message are described. An electronic message, such as an e-mail, a chat request, a torrent file or a text message is initially received. The electronic message can then be compared to known viruses using pattern or signature matching techniques. The electronic message is then transmitted to a virtual machine which executes the electronic message in an environment simulating the destination computing system of the electronic message. The virtual machine monitors execution of the electronic message to identify one or more malicious actions and classifies the electronic message accordingly. For example, message component execution is monitored for attempts to access system files, attempts to access user information, attempts to transmit system configuration data or attempts to transmit user information.

Abstract: Blocking transmission of tainted data using dynamic data tainting is described. For example, sensitive information is stored on a client device as tainted data. The client device generates a data request for retrieving data from a non-trusted entity via a network. A gateway is communicatively coupled to the client device and the network. The gateway receives computer code from the non-trusted entity via the network. The gateway executes the computer code. The gateway tracks the execution of the computer code to determine whether the computer code attempts to access tainted data and transmit the tainted data to an outside entity. The gateway blocks the transmission of the tainted data to the outside entity responsive to determining that the computer code has attempted to access tainted data and transmit the tainted data to an outside entity.

Abstract: A system and method for detecting malicious code in web content is described. A controller receives information, routes the information to the appropriate module and determines whether a user receives the web content or a report of a detection of malicious code. A vulnerability definition generator generates vulnerability definitions. A parser parses web content into static language constructions. A translation engine translates the static language constructions into trap rules, translates the web content into application programming interface (API) calls and determines whether the API calls trigger any of the trap rules. A sandbox engine generates an environment that mimics a browser and executes dynamic parts of the web content and determines whether a dynamic part triggers a trap rule.

Abstract: A system and method for improving code coverage for web code that is analyzed for security purposes by dynamic code execution are described. A controller receives information, routes the information to the appropriate engine, analyzer or module and provides the functionality for improving code coverage for code analyzed for security purposes. A code rewrite engine rewrites code in such a way that all branches and stray functions will be executed. A dynamic analyzer performs dynamic analysis on web content to detect malicious code. Additionally, a static analyzer performs static analysis on web content. The static analyzer scans web content and detects a style of coding, a style of obfuscation of the code or patterns in the code.

Abstract: Analyzing computer code using a tree is described. For example, a client device generates a data request for retrieving data from a non-trusted entity via a network. A gateway is communicatively coupled to the client device and to the network. The gateway is configured to receive computer code from the non-trusted entity via the network. The gateway builds a tree representing the computer code. The tree has one or more nodes. A node of the tree represents a statement from the computer code. The gateway analyzes the statement to identify symbol data. The symbol data describes a name of the variable and the value of the variable. The gateway stores the symbol data in a symbol table.