Thwarting keyloggers using proxies

[0001] The present invention relates generally to a secure communication system. More particularly, this invention relates to methods to thwart a keylogger using a proxy.

[0002] As the Internet and its underlying technologies have become increasingly familiar, attention has become focused on Internet security and computer network security in general. With unprecedented access to information have also come unprecedented opportunities to gain unauthorized access to data, change data, destroy data, make unauthorized use of computer resources, interfere with the intended use of computer resources, etc. These opportunities have been exploited time and time again by many types of malware including, but not limited to computer viruses, worms, Trojan horses, etc.

[0003] Recently, some new types of software have emerged, collectively called “spyware.” Spyware, while not as malicious as the aforementioned conventional viruses, Trojan horses, etc., may still cause problems for computer users. For example, spyware may be designed to log keystrokes, track which websites a computer user visits, and/or transmit personal information to a third party.

[0004] Keylogging is one of the most insidious threats to a user's personal information. Passwords, credit card numbers, and other sensitive or personally identifying information are potentially exposed. Efforts have been made to counter such a threat. One approach is to require a user to enter random keystrokes between entering actual keystrokes of a password or username in order to frustrate the keylogger. However, this method requires extensive user training and intervention.

[0005] Several websites offer the possibility of using an on-screen virtual keyboard that lets a user enter a password by clicking buttons on a screen. These schemes offer variable increments of security based on how they are implemented, but even the simplest ones bypass the majority of keystroke loggers. However, not all Web sites offer such a feature.

[0013] Techniques for thwarting a keylogger using a proxy are described herein. In the following description, numerous details are set forth to provide a more thorough explanation of the embodiments of the present invention. It will be apparent, however, to one skilled in the art, that embodiments of the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring embodiments of the present invention.

[0014] Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification do not necessarily all refer to the same embodiment.

[0015] Accordingly, a service is proposed where people can use a virtual on-screen keyboard in a proxy server to access an account of another Web site. Such a proxy server can either be a straight proxy situation, or the proxy that could cache a set of credentials for the user, such that the user does not have to enter sensitive credentials on a client machine (e.g., the suspect machine).

[0016] Such a service could be operated by letting a user enter Web addresses, usernames, and passwords, possibly saving them in association with a nickname (for example, a user could have “Primary checking account”, “Wife's checking account”, “Mastercard”, etc., and never directly identify the accounts in question). Then, when the user needs to access one of these accounts, the user can go to the proxy service Web site and log in to its account using the virtual on-screen keyboard. Once the user logs in, the user is provided a list of accounts the user can interact with (such as a list of hyperlinks for their set-up accounts). The user clicks on one of their accounts, and the proxy service acts as an intermediary, handling the account login for the user.

[0017] As a result, the user does not have to type in any key on the client machine and the keylogger cannot capture the confidential information that the user enters in order to log into a destination Web site (e.g., user's bank Web site). In addition, a user can use a proxy server to access any selected Web site, even though the selected Web site does not offer an on-screen keyboard (also referred to as an obscured input interface or mechanism).

[0018] FIG. 1 is a block diagram illustrating an example of a network configuration according to one embodiment of the invention. Referring to FIG. 1, according to one embodiment, network configuration 100 includes one or more clients 101-102 communicatively coupled to a server 104 over a network 103. Clients 101-102 may be any kind of client machine such as a personal computer (PC) either as a desktop or a portable computer. For example, clients 101-102 may be computers available in a public domain, such as those available in a public library or a cyber café, etc. In these environments, it is very common that a spyware such as keylogger may be installed in the system. Web server 104 may be any Web server that provides content or services to users. For example, Web server 104 may be part of a Web site of a financial institute. Network 103 may be a wide area network (WAN) such as the Internet, a local area network, or a combination of both.

[0019] In addition, network configuration 100 further includes a proxy server 105 that can be hosted by a computing device such as a server computer. Proxy server 105 provides proxy services between clients 101-102 and Web server 104. That is, the traffic between any of clients 101-102 may have to go through proxy server 105 in order to access Web server 104. According to one embodiment, proxy server 105 includes an obscured input interface 106 that allows a user to enter confidential information such as a username or password without having to type at a client machine such as clients 101-102. As a result, a keylogger installed on a client machine is not able to capture what the user enters on the obscured input interface.

[0020] An obscured input interface may be an on-screen keyboard, also referred to as a virtual keyboard. A virtual keyboard is in a form of graphical user interface having graphical buttons simulating keys of a conventional keyboard. A user can “enter” a key by clicking using a pointing device or via a touch screen interface a corresponding graphical button on the screen and application software can in turn interpret which key has been pressed. In this situation, a keylogger cannot capture what keys a user has entered. At most, what the keylogger can capture is a stream of mouse clicks. In one embodiment, the keys of a virtual keyboard may be presented in a random arrangement which may be different every time the user “enters” a key.

[0021] For example, when a user of client 101 desires to access Web server 104, in this example, a bank Web site to log into a user's bank account, instead of directly accessing server 104, the user accesses proxy server 105. Prior to accessing proxy server 105, the user may have to establish a user account in proxy server 105. The user may long into its account on proxy server 105 using an on-screen keyboard 106 without typing at client 101. Once the user logs into proxy server 105, the user can direct the proxy server to access server 104. The proxy server 105 retrieves a Web page, in this example, a login page, from server 104. Once the login page is loaded, the user can use virtual keyboard 106 again to enter the user's username and/or password, etc. In this configuration, proxy server 105 serves as a straight proxy directing traffic between client 101 and server 104 and provides a virtual keyboard to allow a user to enter confidential information without typing.

[0022] Note that the virtual keyboard 106 may be utilized based on user's discretion. A user may decide to use virtual keyboard 106 only when there is a need to enter confidential information on a Web page. Otherwise, the user may use a conventional keyboard of client 101. Thus, proxy server 105 and/or virtual keyboard 106 may be provided to client 101 as a service hosted by an organization, which may be an independent or third-party entity.

[0023] According to a further embodiment, proxy server 105 includes a database 107 to store a set of confidential information or credentials (e.g., username or password) that are required to be entered in an input field of a login page of server 104. After a user logs into proxy server 105, for example, using virtual keyboard 106, the user can select a Web site (e.g., a URL or universal resource locator) from database to retrieve a login page. Once the login page is retrieved, the user can “enter” a username and/or password by selecting the corresponding username and/or password associated with the selected Web site from database 107. An example of a data structure representing database 107 is shown in FIG. 3. As a result, the user does not even have to use a virtual keyboard when “entering” the confidential information.

[0024] Note that in order to implement the above system, a service provider of proxy server 105 has to be a trustworthy vendor having necessary security that would not expose the confidential information stored in database 107. In order to invoke services provided by proxy server 105, a user may have to subscribe the service and register with proxy server 105. For example, a user may have to provide information as shown in FIG. 3 when registering with the proxy server 105 (e.g., a list of bank accounts, etc.), such that the user can subsequently “enter” the confidential information on a Web page by selecting from database 107 of proxy server 105. Other configurations may also exist.

[0025] Also note that throughout this application, a login page has been used as an example where a user can use the techniques described herein to enter confidential information. It is not so limited, the techniques described herein can also be applied to any page in which a user is required to enter confidential information.

[0026] FIG. 2 is a block diagram illustrating an example of a proxy server according to one embodiment. For example, system 200 may be implemented as part of proxy server 105 of FIG. 1. Referring to FIG. 2, system 200 includes an obscured input interface module 201, a user registration module 202, a proxy module 203, and a credential database 204. Obscured input interface module 201 is responsible for providing an obscured keyboard such as a virtual keyboard to a user. Module 201 is further configured to interpret or map the user interaction with the virtual keyboard to a corresponding key signal representing an actual corresponding key of a conventional keyboard. User registration module 202 is responsible for registering a user and stores a list of Web sites as well as the associated confidential information required to log into the Web sites in database 204.

[0027] Proxy module 203 is responsible for directing traffic between a remote client (e.g., client 101) and a destination Web site (e.g., Web server 104). For example, proxy module 203 serves as a server to client 101 while serving as a client to Web server 104. In response to a request received from a client 101, proxy module 203 repackages the request and sends the request to server 104. After a response has been received from server 104, the proxy module 203 repackages the response and sends the response back to the client 101. Note that some or all of the modules as shown in FIG. 2 may be implemented in software, hardware, or a combination of both software and hardware. Other components may also be included.

[0028] FIG. 4 is a flow diagram illustrating an example of a method for thwarting keyloggers according to one embodiment of the invention. Note that method 400 may be performed by processing logic which may include hardware, software, or a combination of both. For example, method 400 may be performed by proxy server 200 of FIG. 2. In this example, the proxy server serves as a straight proxy. Referring to FIG. 4, at block 401, a proxy server receives a request from a client for accessing a Web page (e.g., a login page) of a remote Web site. In response to the request, the proxy server retrieves the requested login page from the remote Web site and presents the Web page to the client. At block 403, the proxy server provides an on-screen keyboard to allow the user to “enter” confidential information (e.g., username or password) on the login page without typing at the client machine. Once the user has been authenticated by the remote Web sire, at block 404, proxy server directs traffic between the client and the remote Web site to allow the client to access content of the remote Web site.

[0029] FIG. 5 is a flow diagram illustrating an example of a method for thwarting keyloggers according to another embodiment of the invention. Note that method 500 may be performed by processing logic which may include hardware, software, or a combination of both. For example, method 500 may be performed by proxy server 200 of FIG. 2. In this example, the proxy server serves as a proxy that caches confidential information within the proxy. Referring to FIG. 5, at block 501, a proxy server receives a request from a client to access a Web page (e.g., a login page) of a remote Web site. In response to the request, at block 502, the proxy server presents an obscured input interface, such as an on-screen keyboard, to the client to allow the client to “enter” without typing the confidential information (e.g., username or password) in order to log into the proxy server. Once the client logs into the proxy server, at block 503, the proxy server provides a list of Web sites that have been previously registered by the client. In response to the client selecting one of the Web sites from the list, at block 504, the proxy server retrieves the Web page of the selected Web site, for example, based on a URL (universal resource locator) stored within the proxy server. At block 505, the proxy server retrieves confidential information or credentials (e.g., username and/or password) required for log into the Web page of the selected Web site, which are previously stored in the proxy during registration. At block 506, the proxy server populates input fields of the Web page using the retrieved credentials to enable the selected Web site to authenticate the client for the purposes of logging into the selected Web site. As a result, the user does not have to “enter” the necessary confidential information on the Web page. Other operations may also be performed.

[0030] FIG. 6 illustrates a diagrammatic representation of a machine in the exemplary form of a computer system 800 within which a set of instructions, for causing the machine to perform any one or more of the methodologies discussed herein, may be executed. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, and/or the Internet. The machine may operate in the capacity of a server or a client machine in client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a server, a network router, a switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein.

[0031] The exemplary computer system 800 includes a processing device 802, a main memory 804 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 806 (e.g., flash memory, static random access memory (SRAM), etc.), and a data storage device 816, which communicate with each other via a bus 808.

[0032] Processing device 802 represents one or more general-purpose processing devices such as a microprocessor, a central processing unit, or the like. More particularly, the processing device may be complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, or processor implementing other instruction sets, or processors implementing a combination of instruction sets. Processing device 802 may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), network processor, or the like. The processing device 802 is configured to execute the instructions 826 for performing the operations and steps discussed herein.

[0033] The computer system 800 may further include a network interface device 822. The computer system 800 also may include a video display unit 810 (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device 812 (e.g., a keyboard), a cursor control device 814 (e.g., a mouse), and a signal generation device 820 (e.g., a speaker).

[0034] The data storage device 816 may include a computer-accessible storage medium 824 (also known as a machine-readable storage medium or a computer-readable medium) on which is stored one or more sets of instructions or software 826 embodying any one or more of the methodologies or functions described herein. The software 826 may also reside, completely or at least partially, within the main memory 804 and/or within the processing device 802 during execution thereof by the computer system 800, the main memory 804 and the processing device 802 also constituting machine-accessible storage media. The software 826 may further be transmitted or received over a network via the network interface device 822.

[0035] Thus, techniques for thwarting keylogger using a proxy have been described herein. Some portions of the preceding detailed descriptions have been presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the ways used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

[0036] It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

[0037] Embodiments of the present invention also relate to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable medium. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable (e.g., computer-readable) medium includes a machine (e.g., a computer) readable storage medium (e.g., read only memory (“ROM”), random access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory devices, etc.), a machine (e.g., computer) readable transmission medium (electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.)), etc.

[0038] The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method operations. The required structure for a variety of these systems will appear from the description above. In addition, embodiments of the present invention are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of embodiments of the invention as described herein.

[0039] In the foregoing specification, embodiments of the invention have been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of embodiments of the invention as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.