Patent Application
20120151587
1. Field of the Subject Disclosure
The present subject disclosure relates to mobile malware. More specifically, the present subject disclosure relates to detecting proximity-based mobile malware propagation.
2. Background of the Subject Disclosure
Mobile communication devices, such as cellular telephones, have become a common tool of everyday life. Cellular telephones are no longer used simply to place telephone calls. With the number of available features rapidly increasing, cellular telephones are now used for storing addresses, keeping a calendar, reading e-mails, drafting documents, etc. These devices are small enough that they can be carried in a pocket or purse all day, allowing a user to stay in contact almost anywhere. Recent devices have become highly functional, providing applications useful to business professionals as well as the casual user.
Proximity based Mobile Malware Propagation (PMMP) is a category of malware that propagates through proximal connectivity such as WiFi, Bluetooth and infrared. The target victims are any communication device that has a WiFi, Bluetooth, IR, or any other module for proximal communication. These modules are now included in default configurations from many manufacturers. More risk exists for devices that are in “discoverable” mode, which broadcasts connection availability to all nearby devices. Also at risk are devices with either no password or PIN protection, or a weak one. Although slower than propagation schemes such as network-based instant messages and emails, proximity based malware is compelling in its unique advantage that it is unobservable by the service provider network. Thus, it is substantially more challenging to detect proximity than network-based malware propagation.
Proximity-based propagation, by establishing short range wireless connection with victims, is a preferred method for mobile malware. Detection for proximity-based malware is still an open issue due to the fact that such malware has two main advantages compared to the network-based propagation. First, it is difficult to detect since the communication between the attacker and the victims bypasses network-based security inspection. The provider network cannot observe any traffic or signals since such attacks launch locally. Second, it is more likely to succeed due to the weak security in local connectivity technologies. Consequently, there is an increasing number of mobile malware that propagate through proximity based WiFi and Bluetooth connections. Well-known mobile malware that utilize such vulnerabilities include Lasco, Locknut, Cabir, ComWar, PBStealer, and Skuller. Given sufficient time, a Bluetooth malware can infect all susceptible devices in the network. Therefore, it is important to detect such activities locally and quickly.
PMMP can execute in three different ways. One way is through an established connection. If the victim device has already established connections with other devices, the attacker can utilize these established connections to infect other victim devices. Another way is to scan-connect. The attacker can actively scan and search for all the devices within the proximity. Then the malware will attempt to connect to these newly discovered devices and request to establish new connections. If these devices have no or weak passwords and PIN numbers, or if users acknowledge these connection requests, then these devices will be infected. One other way is to re-connect. If the victim device caches previously established connection settings, including security cookies such as password/PIN, then the attacker can avoid security challenges to establish connections, and execute the propagation.
The victim device is a device that has been infected and controlled by the attacker to propagate the malware to other benign devices in proximity. Malware propagation through an established connection is difficult to detect. But the impact of such propagation is restricted in small local areas due to two aspects. First, assume that the mobile devices move frequently, and the average duration of an established connection is short. The probability that the victim device has a live connection when it is infected is very low. Secondly, the number of devices being infected through the established connection is also small, usually one device at a time. Thus, such propagation most likely will die out and impact only a few devices.
What is needed is a method of tracking PMMP in cases where the mobile device is infected without an active connection.
The present subject disclosure solves the above problems with novel devices, systems, and methods which leverage an agent that resides in a mobile communication device to detect PMMP. The agent injects one or several trigger network connections in the candidate connection list. These connections appear as legitimate networks and devices. However, the triggers connect to an agent server on a service provider's network. Essentially, the method is based on the assumption that malware lacks the intelligence to differentiate the trigger network connection from a normal one. Therefore, by attempting to connect through the trigger network connection, the malware reveals itself.
Unlike other detection methods, which need either malware signatures or traces, the proposed system has zero efforts on collecting such statistics and patterns. For this purpose, the light-weight technology can be massively deployed on mobile communication devices easily. The system collects local malware information which is unreachable by the ISP core networks. Whenever a trigger connection is attempted, the agent collects new malware signatures. The proposed proximity-based propagation detection exposes mobile malware on day-1 since these agents are deployed on mobile communication devices at different geographic locations. The proximity-based propagation detection is a passive detection system, which does not use any of the radio resources when the network is attack free. By tracing back the telephone numbers, the infected mobile communication devices are identified, which assists deploying mitigation plans, such as disinfection patches for customers, etc. This trigger system can be extended in many areas, by inserting trigger resources such as links, directories, devices, etc., in “sensitive” places, where risks reside.
In one exemplary embodiment, the present subject disclosure is a mobile communication device. The mobile communication device includes a processor, a memory in communication with the processor, a transceiver in communication with the processor, a malware on the memory, and an agent logic on the memory for discovering a plurality of devices in a proximity, compiling a list of discovered devices in the proximity, inserting a trigger into the list of discovered devices, receiving a request to connect to the trigger from the malware, and reporting a malware activity to an agent server on a network. The trigger appears to the malware to be a discovered device.
In another exemplary embodiment, the present subject disclosure is a system for tracking proximity-based mobile malware propagation. The system includes a network, a mobile communication device in communication with the network, an agent server in communication with the network, a malware on the mobile communication device, and an agent logic on the mobile communication device for discovering a plurality of devices in a proximity, compiling a list of discovered devices in the proximity, inserting a trigger into the list of discovered devices, receiving a request to connect to the trigger, and reporting a malware activity to the agent server. The trigger appears to the malware to be a discovered device.
In yet another exemplary embodiment, the present subject disclosure is a method for tracking proximity-based mobile malware propagation. The method includes discovering a plurality of devices in a proximity, compiling a list of discovered devices in the proximity, inserting a trigger into the list of discovered devices, receiving a request to connect to the trigger, and reporting a malware activity to an agent server on a network. The trigger appears to a malware to be a discovered device.
The present subject disclosure solves the above problems with novel devices, systems, and methods which leverage an agent that resides in a mobile communication device to detect PMMP. The agent injects one or several trigger network connections in the candidate connection list. These connections appear as legitimate networks and devices. However, the triggers connect to an agent server on a service provider's network. Essentially, the method is based on the assumption that malware lacks the intelligence to differentiate the trigger network connection from a normal one. Therefore, by attempting to connect through the trigger network connection, the malware reveals itself.
The total number of deployed malware detection agents depends on the usage of such a system. If it is for the purpose of collecting new PMMP based malware signatures, then a number of selected mobile devices in the network are recruited as agents at different locations. If the purpose is to identify all devices that have been infected by the malware, then triggers should be deployed on each device.
In principal, the proposed idea is extended to detect any attacks that rely on the discover-infect propagation model. In other words, if the malware searches for system resources or devices in its discovery phase, a trigger device is created for the malware to find. For example, a malware attempts to attack flash memory of mobile phones (such as Cardblock attack in 2005) by copying the malware to the victim phone, then a bogus flash drive is deployed, which can be utilized as a trigger system for alarms.
“Mobile communication device”, as used herein and throughout this disclosure, refers to any electronic device capable of wirelessly sending and receiving data. A mobile communication device may have a processor, a memory, a transceiver, an input, and an output. Examples of such devices include cellular telephones, personal digital assistants (PDAs), portable computers, etc. The memory stores applications, software, or logic. Examples of processors are computer processors (processing units), microprocessors, digital signal processors, controllers and microcontrollers, etc. Examples of device memories that may comprise logic include RAM (random access memory), flash memories, ROMS (read-only memories), EPROMS (erasable programmable read-only memories), and EEPROMS (electrically erasable programmable read-only memories).
“Logic”, as used herein and throughout this disclosure, refers to any information having the form of instruction signals and/or data that may be applied to direct the operation of a processor. Logic may be formed from signals stored in a device memory. Software is one example of such logic. Logic may also be comprised by digital and/or analog hardware circuits, for example, hardware circuits comprising logical AND, OR, XOR, NAND, NOR, and other logical operations. Logic may be formed from combinations of software and hardware. On a telecommunication network, logic may be programmed on a server, or a complex of servers. A particular logic unit is not limited to a single logical location on the telecommunication network.
Mobile communication devices communicate with each other and with other elements via a network, for instance, a wireless network, or a wireline network. A “network” can include broadband wide-area networks such as cellular networks, local-area networks (LAN), and personal area networks, such as near-field communication (NFC) networks including BLUETOOTH®. Communication across a network is preferably packet-based; however, radio and frequency/amplitude modulations networks can enable communication between mobile communication devices using appropriate analog-digital-analog converters and other elements. Communication is enabled by hardware elements called “transceivers.” Mobile communication devices may have more than one transceiver, capable of communicating over different networks. For example, a cellular telephone can include a cellular transceiver for communicating with a cellular base station, a Wi-Fi transceiver for communicating with a Wi-Fi network, and a BLUETOOTH® transceiver for communicating with a BLUETOOTH® device. A network typically includes a plurality of elements that host logic for performing tasks on the network.
For the following description, it can be assumed that most correspondingly labeled structures across the figures (e.g., 115 and 215, etc.) possess the same characteristics and are subject to the same structure and function. If there is a difference between correspondingly labeled elements that is not pointed out, and this difference results in a non-corresponding structure or function of an element for a particular embodiment, then that conflicting description given for that particular embodiment shall govern.
This model shows the potential problem in the current local network. Local malware propagation via wireless access points and P2P communication is stealthy due to lack of security deployment on wireless access points and mobile communication devices. The P2P communication used by these mobile communication devices can be any of BLUETOOTH, Near Field Communication (NFC), etc. Wireless access points use any WiFi standard including 802.11a, b, g, i, n, etc.
There are many embodiments of a mobile communication device that are capable of being equipped with the present subject disclosure. For instance, many legacy model cellular telephones are capable of executing the agent logic described above. In other embodiments of the mobile communication device, other displays are used, such as an LED display, OLED display, etc. In some embodiments, the display is used as a touch-sensitive input device, i.e. a touch screen. A touch screen allows the user to view output on the display as well as use the display to provide input. In some touch screen embodiments, the mobile communication device may not have a physical keypad for input. Instead, a virtual keypad is displayed on the touch screen and the user provides input by touching the virtual keys. Other forms of input such as full keyboards, accelerometers, motion sensors, etc., can be utilized in the mobile communication device. The memory can be a non-removable internal memory, or a removable memory such as in a subscriber identity module (SIM) card or a memory card inserted into a memory card reader. Many mobile communication devices have more than one transceiver or a transceiver that supports more than one protocol. For instance, it is not uncommon for a mobile communication device to support cellular radio frequency (RF), WiFi, and BLUETOOTH® protocols.
In other embodiments, the steps performed on the right side of
Scan-connecting is a very general way to search for susceptible devices and adopted by many malware. By the steps explained above, the agent detects the malware inevitably by detecting connection requests to the trigger. Moreover, since most users do not connect to unknown devices, the chance of a user selecting to connect to the trigger(s) is much lower than the malware. This makes the malware easily detected. When the malware on the victim device attempts to scan and make new connections, an exemplary embodiment of the proposed detection scheme works as follows: The user application or the malware requests to scan the proximity for “discoverable” Bluetooth/WiFi devices. Next, the operating system performs network/device discovery. Available networks/devices will respond to the discovery request, and a candidate list will be generated accordingly. The agent logic inserts trigger network(s)/device(s) into the candidate list. The responding networks/devices plus the trigger will be reported to the application or malware.
When compared to scan-connect cases, re-connect cases are more “friendly” to attackers, and the reasons are two folded. First, once the other device is within the proximity, the connection is surely established since the configurations, including the security settings (e.g. password/pin), are cached on the device. Second, the operating system will attempt to re-establish the previous successful connections before attempting to scan for new networks and devices. In order to detect reconnection based malware propagation, a similar technique is used. In this scheme, the agent logic inserts a trigger connection into the cached list of pre-established networks. When a normal user application attempts to re-establish a connection, the user typically knows the last successful used or paired network and device. The user is generally more likely to choose those trusted connections and ignore the trigger. By contrast, the malware does not have such knowledge and inevitably selects the trigger connection upon selecting to connect to all the devices in the cached list.
In summary, for both cases, the agent logic injects trigger(s) into either the returned network/device list for new discovered connections, or in the cached list for pre-established connections. When users choose the desired network/device to establish connections, they are more likely to connect to acknowledged or trusted networks/devices. Meanwhile, the malware blindly chooses a portion or a full list of candidate networks/devices to establish connections. Therefore, under these assumptions, the PMMP-based detection system raises alarms with a relatively low false detection ratio. The false alarms come from legitimate users blindly choosing networks and devices to make connections, which show the same behavior patterns as the victim devices controlled by the malware.
The method is based on the assumption that the user device will not automatically attempt to re-establish connections with the cached networks/devices if these networks/devices are not in proximity. In other words, user devices will first discover whether the cached networks/devices are in proximity if they support automatic network connections without human interaction. Devices violating this assumption will make the normal device behave like a malware since it may also attempt to connect to the trigger. Such devices make detection difficult.
If the scan is a legitimate user application request, the user will most likely ignore the trigger and only choose networks/devices that look benign or well-known to the user, and establish the new connection. But, if the scan is from a malware, then due to the lack of user interaction, the malware is unable to distinguish a trigger from the responded networks/devices. Thus, there is a chance that the malware will select the trigger instead of the legitimate networks/devices. As such PMMP-based scanning increases, the probability of the malware choosing at least one trigger will approach 100% (given an event P, if the probability of P occurring is not strictly 0, it is best to assume that P will occur, since it will almost surely happen, provided that enough time be granted). The agent logic sends the malware reports to the agent server, which reports the malware signatures and victim identities to the service provider for the network.
Other embodiments of the mobile communication device feature a touch screen which performs as a display and an input. The connect button and cancel button can be activated by touching an area of the touch screen in these embodiments.
Other embodiments of the mobile communication device feature a touch screen which performs as a display and an input. The connect button and cancel button can be activated by touching an area of the touch screen in these embodiments.
The foregoing disclosure of the exemplary embodiments of the present subject disclosure has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the subject disclosure to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light of the above disclosure. The scope of the subject disclosure is to be defined only by the claims appended hereto, and by their equivalents.
Further, in describing representative embodiments of the present subject disclosure, the specification may have presented the method and/or process of the present subject disclosure as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present subject disclosure should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present subject disclosure.
