• Journal of Internet Computing and Services
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• v.12 no.5
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• pp.47-61
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• 2011

Recently, the importance of digital forensic has been magnified because of the dramatic increase of cyber crimes and the increasing complexity of the investigation of target systems such as PCs, servers, and database systems. Moreover, some systems have to be investigated with live forensic techniques. However, even though live forensic techniques have been improved, they are still vulnerable to anti-forensic activities when the target systems are remotely accessible by criminals or their accomplices. To solve this problem, we first suggest a layer-based model and the anti-forensic scenarios which can actually be applicable to each layer. Our suggested model, the Anti-Forensic Activites layer-based model, has 5 layers - the physical layer, network layer, OS layer, database application layer and data layer. Each layer has possible anti-forensic scenarios with detailed commands. Second, we propose a fuzzy expert system for effectively detecting anti-forensic activities. Some anti-forensic activities are hardly distinguished from normal activities. So, we use fuzzy logic for handling ambiguous data. We make rule sets with extracted commands and their arguments from pre-defined scenarios and the fuzzy expert system learns the rule sets. With this system, we can detect anti-forensic activities in real time when performing live forensic.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.6
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• pp.855-861
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• 2013

Smartphone is very useful for use in the real life through the improvement of computing power, faster data rate and the variety of applications. On the other hand, using the smartphone has been exposed to a lot of crime. Also, it occurs attempting to delete a data of smartphone memory by anti-forensic tools. In this paper, we investigate and analyze the anti-forensic tools used in the Android smartphone to study the characteristics and techniques of anti-forensic tools. In addition, experiments are performed to validate the availability of anti-forensic tools by the Oxygen Forensic Suite that is a commercial forensic tool.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.1
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• pp.95-102
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• 2015

Smartphone is very useful for use in the real world, but it has been exposed to a lot of crime by smartphone. Also, it occurs attempting to delete a data of smartphone memory by anti-forensic tools. In this paper, we implement an anti-forensic tool used in the Android. In addition, tests to validate the availability of the anti-forensic tool by the Oxygen Forensic Suite that is a commercial forensic tool.

• Convergence Security Journal
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• v.23 no.1
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• pp.97-107
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• 2023

With the popularization of digital devices in the era of the 4th industrial revolution and the increase in cyber crimes targeting them, the importance of securing digital data evidence is emerging. However, the difficulty in securing digital data evidence is due to the use of anti-forensic techniques that increase analysis time or make it impossible, such as manipulation, deletion, and obfuscation of digital data. Such anti-forensic is defined as a series of actions to damage and block evidence in terms of digital forensics, and is classified into data destruction, data encryption, data concealment, and data tampering as anti-forensic techniques. Therefore, in this study, anti-forensic techniques are categorized into data concealment and deletion (obfuscation and encryption), investigate and analyze recent research trends, and suggest future anti-forensic research directions.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.17-26
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• 2017

An anti-forensic data hiding method in an NTFS index record is a method designed for anti-forensics, which records data as a file name in index entries and thereafter the index entries are made to remain in the intentionally generated slack area in a 4KB-sized index record[7]. In this paper, we propose a maximum data allocation rule for an anti-forensic data hiding method in an NTFS index record; i.e., a computational method for storing optimal data to hide data in an index record of NTFS is developed and the optimal solution is obtained by applying the method. We confirm that the result of analyzing the case where the number of index entries n = 7 is the maximum case, and show the screen captures of index entries as experimental results.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.135-144
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• 2014

Since anti-forensics have been developed in order to avoid digital forensic investigation, the forensic methods for analyzing anti-forensic behaviors have been studied in various aspects. Among the factors for user activity analysis, "Iconcache.db" files, which have the icon information of applications, provides meaningful information for digital forensic investigation. This paper illustrates the features of IconCache.db files and suggests the countermeasures against anti-forensics utilizing them.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.13-19
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• 2017

In this paper, study of vehicle fire cases caused by connector and power wiring of anti-lock brake system(ABS) module damage is presented. The purpose of ABS module is to improve braking and steering ability under sudden stop of the vehicle by repeatedly activating and releasing the brake with electric signal via electric control unit. The electric control unit for ABS may experience incomplete contact between power line and signal line or electrical breakdown on the printed circuit board by undergoing repetitive signal change which would consequently result in electrical heat and spark, eventually leading to automotive fire. Therefore, the purpose of this paper is to provide fundamental data by analyzing connector and power wiring of ABS module damage conducive to the precise investigation on the cause of vehicle fire.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.31-40
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• 2016

In this paper, we propose a new anti-forensic method for hiding data in the timestamp of a file in the Windows NTFS filesystem. The main idea of the proposed method is to utilize the 16 least significant bits of the 64 bits in the timestamps. The 64-bit timestamp format represents a number of 100-nanosecond intervals, which are small enough to appear in less than a second, and are not commonly displayed with full precision in the Windows Explorer window or the file browsers of forensic tools. This allows them to be manipulated for other purposes. Every file has $STANDARD_INFORMATION and $FILE_NAME attributes, and each attribute has four timestamps respectively, so we can use 16 bytes to hide data. Without any changes in an original timestamp of "year-month-day hour:min:sec" format, we intentionally put manipulated data into the 16 least significant bits, making the existence of the hidden data in the timestamps difficult to uncover or detect. We demonstrated the applicability and feasibility of the proposed method with a test case.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.4
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• pp.327-337
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• 2015

This work provides new forensic techinque to a hide message on a directory index in Windows NTFS file system. Behavior characteristics of B-tree, which is apoted to manage an index entry, is utilized for hiding message in slack space of an index record. For hidden message not to be exposured, we use a disguised file in order not to be left in a file name attribute of a MFT entry. To understand of key idea of the proposed technique, we describe B-tree indexing method and the proposed of this work. We show the proposed technique is practical for anti-forensic usage with a real message hiding case using a developed software tool.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.2
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• pp.387-396
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• 2016

As the number of people using digital devices has increased, the digital forensic, which aims at finding clues for crimes in digital data, has been developed and become more important especially in court. Together with the development of the digital forensic, the anti-forensic which aims at thwarting the digital forensic has also been developed. As an example, with anti-forensic technology the criminal would delete an digital evidence without which the investigator would be hard to find any clue for crimes. In such a case, recovery techniques on deleted or damaged information will be very important in the field of digital forensic. Until now, even though EVTX(event log)-based recovery techniques on deleted files have been presented, but there has been no study to retrieve event log data itself, In this paper, we propose some recovery algorithms on deleted or damaged event log file and show that our recovery algorithms have high success rate through experiments.