Robust Low-Overhead Binary Rewriting: Design, Extensibility, And Customizability

Binary rewriting is the foundation of a wide range of binary analysis tools and techniques, including securing untrusted code, enforcing control-flow integrity, dynamic optimization, profiling, race detection, and taint tracking to prevent data leaks. There are two equally important and necessary criteria that a binary rewriter must have: it must be robust and incur low overhead. First, a binary rewriter must work for different binaries, including those produced by commercial compilers from a wide variety of languages, and possibly modified by obfuscation tools. Second, the binary rewriter must be low overhead. Although the off-line use of programs, such as testing and profiling, can tolerate large overheads, the use of binary rewriters in deployed programs must not introduce significant overheads; typically, it should not be more than a few percent. Existing binary rewriters have their challenges: static rewriters do not reliably work for stripped binaries (i.e., those without relocation information), and dynamic rewriters suffer from high base overhead. Because of this high overhead, existing dynamic rewriters are limited to off-line testing and cannot be practically used in deployment. In the first part, we have designed and implemented a dynamic binary rewriter called RL-Bin, a robust binary rewriter that can instrument binaries reliably with very low overhead. Unlike existing static rewriters, RL-Bin works for all benign binaries, including stripped binaries that do not contain relocation information. In addition, RL-Bin does not suffer from high overhead because its design is not based on the code-cache, which is the primary mechanism for other dynamic rewriters such as Pin, DynamoRIO, and Dyninst. RL-Bin's design and optimization methods have empowered RL-Bin to rewrite binaries with very low overhead (1.04x on average for SPECrate 2017) and very low memory overhead (1.69x for SPECrate 2017). In comparison, existing dynamic rewriters have a high runtime overhead (1.16x for DynamoRIO, 1.29x for Pin, and 1.20x for Dyninst) and have a bigger memory footprint (2.5x for DynamoRIO, 2.73x for Pin, and 2.3x for Dyninst). RL-Bin differentiates itself from other rewriters by having negligible overhead, which is proportional to the added instrumentation. This low overhead is achieved by utilizing an in-place design and applying multiple novel optimization methods. As a result, lightweight instrumentation can be added to applications deployed in live systems for monitoring and analysis purposes. In the second part, we present RL-Bin++, an improved version of RL-Bin, that handles various problematic real-world features commonly found in obfuscated binaries. We demonstrate the effectiveness of RL-Bin++ for the SPECrate 2017 benchmark obfuscated with UPX, PECompact, and ASProtect obfuscation tools. RL-Bin++ can efficiently instrument heavily obfuscated binaries (overhead averaging 2.76x, compared to 4.11x, 4.72x, and 5.31x overhead respectively caused by DynamoRIO, Dyninst, and Pin). However, the major accomplishment is that we achieved this while maintaining the low overhead of RL-Bin for unobfuscated binaries (only 1.04x). The extra level of robustness is achieved by employing dynamic deobfuscation techniques and using a novel hybrid in-place and code-cache design. Finally, to show the efficacy of RL-Bin in the development of sophisticated and efficient analysis tools, we have designed, implemented, and tested two novel applications of RL-Bin; An application-level file access permission system and a security tool for enforcing secure execution of applications. Using RL-Bin's system call instrumentation capability, we developed a fine-grained file access permission system that enables the user to define separate file access policies for each application. The overhead is very low, only 6%, making this tool practical to be used in live systems. Secondly, we designed a security enforcement tool that instruments indirect control transfer instructions to ensure that the program execution follows the predetermined anticipated path. Hence, it would protect the application from being hijacked. Our implementation showed effectiveness in detecting exploits in real-world programs while being practical with a low overhead of only 9%

Management and valorisation of wastes through use in producing alkali-activated cement materials

There is a growing global interest in maximising the re-use and recycling of waste, to minimise the environmental impacts associated with waste treatment and disposal. Use of high-volume wastes in the production of blended or novel cements (including alkali-activated cements) is well known as a key pathway by which these wastes can be re-used. This paper presents a critical overview of the urban, agricultural, mining and industrial wastes that have been identified as potential precursors for the production of alkali-activated cement materials, or that can be effectively stabilised/solidified via alkali activation, to assure their safe disposal. The central aim of this review is to elucidate the potential advantages and pitfalls associated with the application of alkali-activation technology to a wide variety of wastes that have been claimed to be suitable for the production of construction materials. A brief overview of the generation and characteristics of each waste is reported, accompanied by identification of opportunities for the use of alkali-activation technology for their valorisation and/or management

Psychometric Properties of the Persian Version of the Multiple Lifestyle Behaviors Questionnaire and its Measurement During the COVID-19 Outbreak: The Role of Gender and Exercise

Background: This study aimed to assess the psychometric properties of the Persian version of the multiple lifestyle behaviors (MLSB) questionnaire during the COVID-19 outbreak by considering the role of gender and exercise. Methods: This research population consisted of all Iranian men and women in the age range of 18 to 65 years living in Iran in the summer of 2021. The statistical sample consisted of 299 female (n=225) and male (n=74) Iranian athletes (of team and individual disciplines) and non-athletes selected through a snowball sampling method by sharing the questionnaire on social media networks. This questionnaire includes eight factors: Life satisfaction, mental wellbeing, social participation, mood and feeling, technology use, diet behavior, physical activity, and sleep quality. Confirmatory factor analysis was used to examine the construct validity, and Cronbach's alpha coefficient and split-half coefficient were used to assess reliability. Concurrent validity was also measured using Pearson's correlation coefficient The obtained data were analyzed with SPSS version 23 and AMOS version 22 softwares. Results: The obtained results showed that all factors of the questionnaire have factorial loading or high correlation with the whole MLSB questionnaire (P<0.001). The correlation between the scores of the questionnaire dimensions ranged from 0.12 to 0.678 (P<0.001) and showed suitable validity. The obtained reliabilities in all dimensions in the questionnaire were over 0.7 and desirable. Conclusion: In the present study, the psychometric properties of the MLSB questionnaire were assessed for healthy athlete and non-athlete adults, providing desirable reliability and validity. The researchers are suggested to use the Persian version of this questionnaire in the future research and also assess the psychometric properties of the questionnaire for adolescents, people with special diseases, Fields and different skill/sport levels and sport experiences

Mix design for fly ash based oil palm shell geopolymer lightweight concrete

This paper presents the experimental results of an on-going research project to produce geopolymer lightweight concrete using two locally available waste materials - low calcium fly ash (FA) and oil palm shell (OPS) - as the binder and lightweight coarse aggregate, respectively. A total of 32 mixes using different mixture proportions were prepared to get an appropriate mix design for fly ash based oil palm shell geopolymer lightweight concrete (OPSGPC). A mixture of sodium hydroxide and sodium silicate in different molarities was used as an alkali activator. The variables used in this investigation include the fly ash content, molarity and condition of OPS. The proposed mix design differs widely from the procedure used for mix proportioning of concrete produced with conventional lightweight and normal weight aggregates. The increase in FA content reduces the strength significantly due to additional water used for workability. The increase in molarity from 14 M to 16 M did not have desired effect on the compressive strength. However, the use of OPS with SSD condition produced higher strength than that of AD condition. The OPSGPC with 14 M, FA content of 480 kg/m3 and water to FA ratio of 0.34 produced 28-day compressive strength of about 32 MPa and is recommended for producing structural grade 30 OPSGPC. The demoulded densities of OPSGPC were within the limit of 2000 kg/m3 for lightweight concrete