An Evasion Attack against ML-based Phishing URL Detectors

Background: Over the year, Machine Learning Phishing URL classification (MLPU) systems have gained tremendous popularity to detect phishing URLs proactively. Despite this vogue, the security vulnerabilities of MLPUs remain mostly unknown. Aim: To address this concern, we conduct a study to understand the test time security vulnerabilities of the state-of-the-art MLPU systems, aiming at providing guidelines for the future development of these systems. Method: In this paper, we propose an evasion attack framework against MLPU systems. To achieve this, we first develop an algorithm to generate adversarial phishing URLs. We then reproduce 41 MLPU systems and record their baseline performance. Finally, we simulate an evasion attack to evaluate these MLPU systems against our generated adversarial URLs. Results: In comparison to previous works, our attack is: (i) effective as it evades all the models with an average success rate of 66% and 85% for famous (such as Netflix, Google) and less popular phishing targets (e.g., Wish, JBHIFI, Officeworks) respectively; (ii) realistic as it requires only 23ms to produce a new adversarial URL variant that is available for registration with a median cost of only $11.99/year. We also found that popular online services such as Google SafeBrowsing and VirusTotal are unable to detect these URLs. (iii) We find that Adversarial training (successful defence against evasion attack) does not significantly improve the robustness of these systems as it decreases the success rate of our attack by only 6% on average for all the models. (iv) Further, we identify the security vulnerabilities of the considered MLPU systems. Our findings lead to promising directions for future research. Conclusion: Our study not only illustrate vulnerabilities in MLPU systems but also highlights implications for future study towards assessing and improving these systems.Comment: Draft for ACM TOP

Treeline dynamics with climate change at the central Nepal Himalaya

Treeline shifting in tandem with climate change has widely been reported from various parts of the world. In Nepal, several impacts of climate change on the physical environment have been observed, but study on the biological impacts is lacking. This dendrochronological study was carried out at the treeline in the high mountain slope of Kalchuman Lake (3750-4003 m a.s.l.) area of Manaslu Conservation Area in the central Nepal Himalaya to explore the impact of climate change on the treeline dynamic. Two belt transect plots (size: 20 m wide, > 250 m long) were laid which included treeline as well as tree species limit. Ecological mapping of all individuals of dominant trees Abies spectabilis and Betula utilis was done and their tree cores were collected. Stand character and age distribution revealed an occurrence of more matured B. utilis (max. age 198 years) compared to A. spectabilis (max. age 160 years). A. spectabilis contained an overwhelmingly high population (89) of younger plants (< 50 years) indicating its high recruitment rate. Population age structure along the elevation gradient revealed an upward shifting of A. spectabilis at the rate of 2.61 m year-1 since AD 1850. The upper distribution limit of B. utilis was found to be stagnant in the past few decades. An increment in plant density as well as upward shifting in the studied treeline ecotones was observed. The temporal growth of A. spectabilis was correlated negatively with the monthly mean and minimum temperature of June to September of the current and previous year. The regeneration of A. spectabilis, on the other hand, was positively correlated with August precipitation and monthly maximum temperature of the month of the current year. The growth and regeneration of A. spectabilis was more sensitive to maximum and minimum temperature rather than average temperature. The growth of the B. utilis was mainly limited by moisture stress during the pre-monsoon season. As these two species presented species-specific responses to climate change with differential pattern in regeneration condition, much wider differences are anticipated in their population status as climate continues to change throughout the century

Life after armed group involvement in Nepal: a clinical ethnography of psychological well-being of former 'child soldiers' over time

Little is known about the longitudinal effects of early age involvement of young people in armed groups and their well-being as they return to strongly affected, politicised communities. Current research and policy are often driven by the assumption of a causal relationship between participation in this war experience and psychological damage. This article explores the role of young people’s armed group experience during the Nepal People’s War, compared with post-conflict stressors, in shaping intra-psychic impact and distress, and which processes enable well-being and resilient functioning. Findings are reported from an 18-month clinical ethnography of a cohort of 17 Nepalese young subjects, where participant-observation methods were used to explore their daily lives after exiting the armed group and follow-up research conducted six years later. The findings highlighted limited evidence for on-going intra-psychic impact and distress related directly to their armed group experience; when such distress occurred, it appeared to be generated more by the structural violence of their environments. The key constituents determining their well-being included: a sense of closeness through emotional connectedness with their family, ideological proximity with the values of the armed group, closeness in their bond with the community, and the social-emotional-economic capital available to them to navigate the harsh structural constraints of post-conflict life. These data further challenge the prevailing assumption that this war experience inevitably leads to psychological damage, and the article argues that structural violence often plays a predominant role in cases where psychological distress does arise

Tunable cobalt nanoparticle synthesis by intense pulse flash annealing

Magnetically susceptible materials can serve as a basis for the directed assembly of nanoscale network devices which can be used to extract energy from phase change materials. So far, matrix production cost has been a prohibitive factor in the realization of real world applications. Here we report a cost-effective method to synthesize magnetic nanoparticles. Samples were fabricated by sputtering magnetic thin films on carbon nanotube substrates followed by xenon intense pulsed light flash annealing. The results indicate that spatially ordered magnetic spheres can be tuned by various parameters such as initial thin film thickness, xenon lamp exposure excitation energy, local surface geometries, and the presence of an external magnetic field during annealing

Disaster risk profile and existing legal framework of Nepal: Floods and landslides

Nepal has a complicated geophysical structure that is prone to various kinds of disasters. Nepal ranks the most disaster-prone country in the world and has experienced several natural calamities, causing high property and life losses. Disasters are caused by natural processes, but may be increased by human activities. The overall objective of this paper is to analyze the disaster risk profile and existing legal framework of Nepal. The paper is based on secondary data sources. Major causative factors for floods and landslides are heavy and continuous rainfall, outburst floods, infrastructure failure, and deforestation. Historical data of natural disasters in Nepal show that water-induced disasters have killed hundreds of people and affected thousands every year. Likewise, properties worth millions of US dollars have been damaged. There is an increasing trend toward landslides and floods, which will likely continue to rise if proper intervention is not taken. A positive correlation between water-induced disasters and deaths has been observed. Nepal has a poor Index for Risk Management (INFORM). There are fluctuations in the recording of death data caused by flood and landslides. The Government of Nepal focuses more on the response phase than on the preparedness phase of disasters. The existing disaster management act seems to be weak and outdated. There is a gap in current legal procedure, so the country is in dire need of a comprehensive legal framework. The new proposed act seems to take a much broader approach to disaster management. With a long-term vision of managing disaster risk in the country, the Government of Nepal has begun the Nepal Risk Reduction Consortium (NRRC) in collaboration with development and humanitarian partners. In order to improve the vulnerability of Nepal, an early warning system, mainstreaming disasters with development, research activities, community participation and awareness, and a rainfall monitoring system must all be a focus

Epidemiology, impact and control of rabies in Nepal : a systematic review

Background: Rabies is a vaccine-preventable viral zoonosis belonging to the group of neglected tropical diseases. Exposure to a rabid animal may result in a fatal acute encephalitis if effective post-exposure prophylaxis is not provided. Rabies occurs worldwide, but its burden is disproportionately high in developing countries, including Nepal. We aimed to summarize current knowledge on the epidemiology, impact and control of rabies in Nepal. Methods: We performed a systematic review of international and national scientific literature and searched grey literature through the World Health Organization Digital Library and the library of the National Zoonoses and Food Hygiene Research Centre, Nepal, and through searching Google and Google Scholar. Further data on animal and human rabies were obtained from the relevant Nepalese government agencies. Finally, we surveyed the archives of a Nepalese daily to obtain qualitative information on rabies in Nepal. Findings: So far, only little original research has been conducted on the epidemiology and impact of rabies in Nepal. Per year, rabies is reported to kill about 100 livestock and 10–100 humans, while about 1,000 livestock and 35,000 humans are reported to receive rabies post-exposure prophylaxis. However, these estimates are very likely to be serious underestimations of the true rabies burden. Significant progress has been made in the production of cell culture-based anti-rabies vaccine and rabies immunoglobulin, but availability and supply remain a matter of concern, especially in remote areas. Different state and non-state actors have initiated rabies control activities over the years, but efforts typically remained focalized, of short duration and not harmonized. Communication and coordination between veterinary and human health authorities is limited at present, further complicating rabies control in Nepal. Important research gaps include the reporting biases for both human and animal rabies, the ecology of stray dog populations and the true contribution of the sylvatic cycle. Interpretation: Better data are needed to unravel the true burden of animal and human rabies. More collaboration, both within the country and within the region, is needed to control rabies. To achieve these goals, high level political commitment is essential. We therefore propose to make rabies the model zoonosis for successful control in Nepal