Aligot: cryptographic function identification in obfuscated binary programs

International audienceAnalyzing cryptographic implementations has important ap- plications, especially for malware analysis where they are an integral part both of the malware payload and the unpacking code that decrypts this payload. These implementations are often based on well-known cryptographic functions, whose description is publicly available. While potentially very use- ful for malware analysis, the identification of such crypto- graphic primitives is made difficult by the fact that they are usually obfuscated. Current state-of-the-art identification tools are ineffective due to the absence of easily identifiable static features in obfuscated code. However, these imple- mentations still maintain the input-output (I/O) relation- ship of the original function. In this paper, we present a tool that leverages this fact to identify cryptographic functions in obfuscated programs, by retrieving their I/O parameters in an implementation-independent fashion, and comparing them with those of known cryptographic functions. In ex- perimental evaluation, we successfully identified the crypto- graphic functions TEA, RC4, AES and MD5 in obfuscated programs. In addition, our tool was able to recognize basic operations done in asymmetric ciphers such as RSA

Leaky severe combined immunodeficiency in mice lacking non-homologous end joining factors XLF and MRI

Non-homologous end-joining (NHEJ) is a DNA repair pathway required to detect, process, and ligate DNA double-stranded breaks (DSBs) throughout the cell cycle. The NHEJ pathway is necessary for V(D)J recombination in developing B and T lymphocytes. During NHEJ, Ku70 and Ku80 form a heterodimer that recognizes DSBs and promotes recruitment and function of downstream factors PAXX, MRI, DNA-PKcs, Artemis, XLF, XRCC4, and LIG4. Mutations in several known NHEJ genes result in severe combined immunodeficiency (SCID). Inactivation of Mri, Paxx or Xlf in mice results in normal or mild phenotype, while combined inactivation of Xlf/Mri, Xlf/Paxx, or Xlf/Dna-pkcs leads to late embryonic lethality. Here, we describe three new mouse models. We demonstrate that deletion of Trp53 rescues embryonic lethality in mice with combined deficiencies of Xlf and Mri. Furthermore, Xlf-/-Mri-/-Trp53+/- and Xlf-/-Paxx-/-Trp53+/- mice possess reduced body weight, severely reduced mature lymphocyte counts, and accumulation of progenitor B cells. We also report that combined inactivation of Mri/Paxx results in live-born mice with modest phenotype, and combined inactivation of Mri/Dna-pkcs results in embryonic lethality. Therefore, we conclude that XLF is functionally redundant with MRI and PAXX during lymphocyte development in vivo. Moreover, Mri genetically interacts with Dna-pkcs and Paxx

Specific activity of superoxide dismutase in stallion seminal plasma is related to sperm cryotolerance

While the removal of seminal plasma is a routine practice prior to equine sperm cryopreservation, this fluid contains the main source of antioxidant enzymes able to scavenge these reactive oxygen species. Therefore, stallion seminal plasma components may have an impact on ejaculate freezability. Against this background, this study was designed to investigate whether the activities of the main stallion seminal plasma antioxidant enzymes are related to sperm cryotolerance. With this purpose, 16 ejaculates were collected from 14 healthy stallions, and each ejaculate was split into two aliquots. The first one was used to evaluate the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GSR) in seminal plasma. The second aliquot was extended and then processed for cryopreservation. Sperm motility and viability were evaluated before and after cryopreservation, and ejaculates were classified as of good (GFE) or poor freezability (PFE) based on total motile and viable spermatozoa at post-thaw. We observed that, while the specific activities of CAT, GPX, and GSR were similar between GFE and PFE, that of SOD was significantly (p < 0.05) higher in GFE than in PFE. We can thus conclude that, in stallions, the specific activity of SOD in the seminal plasma of a given ejaculate might be related to its freezability

Synthesis and Luminescence Modulation of Pyrazine-Based Gold(III) Pincer Complexes

The first examples of pyrazine-based gold(III) pincer complexes have been synthesized; their intense photoemissions can be modified by interactions with the non-coordinating pyrazine-N atom. Luminescence modulation is possible without the need for altering the ligand framework. Emissions shift from red (77 K) to blue (298 K) due to thermally activated delayed fluorescence (TADF

Highly photoluminescent copper carbene complexes based on prompt rather than delayed fluorescence

Linear two-coordinate copper complexes of cyclic (alkyl)(amino)-carbenes (CAAC)CuX (X = halide) show photoluminescence with solid-state quantum yields of up to 96%; in contrast to previously reported Cu photoemitters the emission is independent of temperature over the range T = 4 – 300 K and occurs very efficiently by prompt rather than delayed fluorescence, with lifetimes in the sub-nanosecond range

Investigation of Prolactin Receptor Activation and Blockade Using Time-Resolved Fluorescence Resonance Energy Transfer

The prolactin receptor (PRLR) is emerging as a therapeutic target in oncology. Knowledge-based drug design led to the development of a pure PRLR antagonist (Del1-9-G129R-hPRL) that was recently shown to prevent PRL-induced mouse prostate tumorogenesis. In humans, the first gain-of-function mutation of the PRLR (PRLRI146L) was recently identified in breast tumor patients. At the molecular level, the actual mechanism of action of these two novel players in the PRL system remains elusive. In this study, we addressed whether constitutive PRLR activation (PRLRI146L) or PRLR blockade (antagonist) involved alteration of receptor oligomerization and/or of inter-chain distances compared to unstimulated and PRL-stimulated PRLR. Using a combination of various biochemical and spectroscopic approaches (co-IP, blue native electrophoresis, BRET1), we demonstrated that preformed PRLR homodimers are altered neither by PRL- or I146L-induced receptor triggering, nor by antagonist-mediated blockade. These findings were confirmed using a novel time-resolved fluorescence resonance energy transfer (TR-FRET) technology that allows monitoring distance changes between cell surface tagged receptors. This technology revealed that PRLR blockade or activation did not involve detectable distance changes between extracellular domains of receptor chains within the dimer. This study merges with our previous structural investigations suggesting that the mechanism of PRLR activation solely involves intermolecular contact adaptations leading to subtle intramolecular rearrangements

Proteasomes associated with the Blm10 activator protein antagonize mitochondrial fission through degradation of the fission protein Dnm1

L

Evaluation of a knowledge translation strategy to improve policymaking and practices in health promotion and disease prevention setting in French regions: TC-REG, a realist study

OBJECTIVE: This paper presents the results of a realist evaluation of a knowledge translation (KT) intervention implemented in the field of health promotion and disease prevention at the local level in France. DESIGN: Realist evaluation study. SETTING: The target population comprised decision-makers and field professionals working in prevention and public health services operating in regions of France (ie, ARS (Agence Régionale de Santé: regional health agency), IREPS (Instance Régionale d'Education et de Promotion de la Santé pour tous: regional organisation for health promotion and education) and their partners). PARTICIPANTS: This evaluation was based on data collected from 2 seminars, 82 interviews, 18 observations and 4 focus groups over 18 months. INTERVENTION: The TC-REG intervention aimed to increase the use of evidence in cancer prevention, health promotion and disease prevention across four geographical regions in France. The intervention combined various activities: Supporting access to and adaptation of usable evidence, strengthening professionals' skills in analysing, adopting and using policy briefs, and facilitating the use of evidence in organisations and processes. RESULTS: The collected data was used to define favourable/unfavourable contexts for the use of scientific data and mechanisms to be activated to encourage the use of scientific knowledge. From these raw results eight final refined middle-range theories were defined. Organised around the mechanisms to be activated, these middle-range theories illustrate how to activate knowledge and under what conditions. These analyses provided a basis for the production of seven operational and contextualised recommendations to develop KT to inform regional policymaking regarding health promotion and disease prevention. CONCLUSION: The results obtained from the analyses led us to formulate two perspectives of an operational nature for the benefit of those involved in prevention and health promotion

Physicochemical features of Amazonian water typologies for water resources management

Today, an increasing amount of hydrochemical data indicate that the chemical composition of Amazonian rivers varies much more than the traditional classification indicates. In this first comprehensive review of Amazonian river chemistry, we synthesized critical information from 400 scientific publications and distinguish the types: white, black, clear, intermediate type A and type B. We show the distribution of such rivers across the Amazon basin and the limitations of such approach. These insights into Amazonian river classification provide a new understanding of their baseline limnological conditions. They have implications for sustainable management of Amazonian freshwater systems. © 2020 IOP Publishing Ltd