Ao Kaspersky Lab

Dmitry V Karasovsky

Vladislav V Pintiysky

Maxim Y Golovkin

Vitaly V Butuzov

Denis Y Kobychev

Dmitry A Kirsanov

Denis V Anikin

Alexey V Monastyrsky

Mikhail A Pavlyushchik

Alexey S Shulmin

Disclosed are systems and methods for recognizing files as malicious. One exemplary method comprises intercepting a file for analysis received at a computing device of a user, opening the file for analysis in an environment for safe execution, generating a log that stores a portion of information occurring during opening of the file for analysis in the environment for safe execution, analyzing the log to recognize a first set of security related events from the portion of information, tracking a second set of security related events when the file for analysis is opened on the computing device, comparing the second set of security related events and the first set of security related events to identify a discrepancy; and in response to identifying the discrepancy, recognizing the file under analysis as malicious.

Method of detecting malicious files resisting analysis in an isolated environment

Disclosed is a method for analyzing a log for conducting an antivirus scan of a file. The method includes opening a file in a virtual machine. The opening of the file includes execution of a guest process having a thread in a virtual processor of the virtual machine. A plurality of events in the thread of the guest process is intercepted. Registers associated with a system call made during execution of the first thread of the guest process are determined. Execution of the thread of the guest process is halted. In a log associated with the opening of the file, information is saved indicating events intercepted during execution of the thread in an altered guest physical memory page, and context data of the virtual processor. Using at least one template having rules, the saved log is analyzed to determine whether the file opened in the virtual machine is harmful.

System and method for analyzing a log in a virtual machine based on a template

Disclosed are systems and methods for analysis of files for maliciousness and determining an action. An exemplary method comprises: opening a file, by a processor, in a virtual machine, intercepting an event arising in an execution of a thread of a process created upon opening of the file, determining, a context of the processor on which the thread is being executed, the determination including reading register values of the processor and a stack, comparing the context with rules that check: a behavior of the thread of the process, a changing, by the thread, of attributes of the file, and an access of the thread to the Internet, and based on a result of the comparison, performing at least one of: recognizing the file as being malicious, halting the execution of the thread, changing the context of the processor, and waiting for a next intercepted event.

System and method of analysis of files for maliciousness and determining an action

Disclosed are systems and methods for generating a log for conducting an antivirus scan of a file. The described technique includes opening a file in a virtual machine, which causes execution of a guest process and a thread in a (virtual) processor of the virtual machine. The technique includes identifying, during execution of the first thread, events that involve alteration of guest physical memory pages of the virtual machine. The technique determines altered guest physical memory page based on analysis of the log and identifies when a transfer of control to altered guest physical memory pages has occurred. The resultant log for analysis by a security application includes information indicating the events occurring during execution of the thread in the altered guest physical memory page, and context data of the virtual processor on which the thread is being executed.

System and method of forming a log in a virtual machine for conducting an antivirus scan of a file

Disclosed are system and method for detecting malicious code in files. One exemplary method comprises: intercepting, by a processor, one or more application program interface (API) calls during an execution of a process launched from a file of a computing device; determining and detecting, by the processor, a presence of an exit condition of the process; in response to detecting the exit condition, identifying one or more signatures of a first type and transferring one or more saved memory dumps of the computing device to an emulator for execution; and determining and identifying a malicious code in the file in response to detecting one or more signatures of a second type based at least upon execution results of the transferred memory dumps of the computing device.

System and method of detecting malicious code in files

Disclosed are systems and methods of analysis of files for maliciousness in a virtual machine. An exemplary method comprises: opening and executing a file by a processor in a virtual machine; intercepting an event arising in the process of execution of a thread of a process created upon opening of the file; halting the execution of the thread; reading the context of the processor on which the thread is being executed; comparing the context of the processor with one or more rules; and based on the results of the comparison, performing at least one of: recognizing the file as being malicious; halting the execution of the process created upon opening of the file; changing the context of the processor; and waiting for the next intercepted event.

System and method of analysis of files for maliciousness in a virtual machine

A method and system are provided for performing an antivirus scan of a file on a virtual machine. An example method includes performing a first execution of the file on the virtual machine, recording a first log that includes an API function call and an internal event detected during execution, and determining if any signatures in the log are stored in a signatures database. Moreover, if no signatures in the first log are found in the first database of signatures, the file is classified as not malicious. In contrast, if at least one signature is found, a second execution of the file is perform and a second log is recorded that includes a detected internal event. Moreover, the method includes determining if any signatures in the second log are stored in a second database of signatures; and classifying the file as not malicious if no signatures are found.

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Moscow, Russia

Dmitry V Karasovsky