Malwise-an effective and efficient classification system for packed and polymorphic malware

Signature-based malware detection systems have been a much used response to the pervasive problem of malware. Identification of malware variants is essential to a detection system and is made possible by identifying invariant characteristics in related samples. To classify the packed and polymorphic malware, this paper proposes a novel system, named Malwise, for malware classification using a fast application-level emulator to reverse the code packing transformation, and two flowgraph matching algorithms to perform classification. An exact flowgraph matching algorithm is employed that uses string-based signatures, and is able to detect malware with near real-time performance. Additionally, a more effective approximate flowgraph matching algorithm is proposed that uses the decompilation technique of structuring to generate string-based signatures amenable to the string edit distance. We use real and synthetic malware to demonstrate the effectiveness and efficiency of Malwise. Using more than 15,000 real malware, collected from honeypots, the effectiveness is validated by showing that there is an 88 percent probability that new malware is detected as a variant of existing malware. The efficiency is demonstrated from a smaller sample set of malware where 86 percent of the samples can be classified in under 1.3 seconds.

Isolation and characterization of 12 polymorphic tetranucleotide microsatellite loci in the apostlebird (Struthidea cinerea)

The apostlebird (Struthidea cinerea) is an Australian endemic passerine belonging to the Corcoracidae family. The species is highly gregarious throughout the year and the name of the species refers to the apparent prevalence of social groups of around 12 birds. The species is becoming a model system for the study of sociality in vertebrates, which will require the analysis of relatedness, paternity and maternity. We characterize 12 microsatellite loci tested for polymorphism on 25 individuals from a population in western New South Wales, Australia. The number of alleles ranged from 4 to 9 per locus. Expected heterozygosities ranged from 0.69 to 0.88. This microsatellite panel will facilitate future studies that will advance our understanding of dispersal processes, inbreeding avoidance and reproductive skew in social animals.

Influence of processing conditions on polymorphic behavior, crystallinity, and morphology of electrospun poly(VInylidene fluoride) nanofibers

The polymorphism and crystallinity of poly(vinylidene fluoride) (PVDF) membranes, made from electrospinning of the PVDF in pure N,N-dimethylformamide (DMF) and DMF/acetone mixture solutions are studied. Influence of the processing and solution parameters such as flow rate, applied voltage, solvent system, and mixture ratio, on nanofiber morphology, total crystallinity, and crystal phase content of the nanofibers are investigated using scanning electron microscopy, wide-angle X-ray scattering, differential scanning calorimetric, and Fourier transform infrared spectroscopy. The results show that solutions of 20% w/w PVDF in two solvent systems of DMF and DMF/acetone (with volume ratios of 3/1 and 1/1) are electrospinnable; however, using DMF/acetone volume ratio of 1/3 led to blockage of the needle and spinning process was stopped. Very high fraction of β-phase (∼79%-85%) was obtained for investigated nanofiber, while degree of crystallinity increased to 59% which is quite high due to the strong influence of electrospinning on ordering the microstructure. Interestingly, ultrafine fibers with the diameter of 12 and 15 nm were obtained in this work. Uniform and bead free nanofiber was formed when a certain amount of acetone was added in to the electrospinning solution.