291 research outputs found
On the security of machine learning in malware C & C detection:a survey
One of the main challenges in security today is defending against malware attacks. As trends and anecdotal evidence show, preventing these attacks, regardless of their indiscriminate or targeted nature, has proven difficult: intrusions happen and devices get compromised, even at security-conscious organizations. As a consequence, an alternative line of work has focused on detecting and disrupting the individual steps that follow an initial compromise and are essential for the successful progression of the attack. In particular, several approaches and techniques have been proposed to identify the command and control (C&C) channel that a compromised system establishes to communicate with its controller. A major oversight of many of these detection techniques is the design's resilience to evasion attempts by the well-motivated attacker. C&C detection techniques make widespread use of a machine learning (ML) component. Therefore, to analyze the evasion resilience of these detection techniques, we first systematize works in the field of C&C detection and then, using existing models from the literature, go on to systematize attacks against the ML components used in these approaches
Critical Impact of Social Networks Infodemic on Defeating Coronavirus COVID-19 Pandemic: Twitter-Based Study and Research Directions
News creation and consumption has been changing since the advent of social
media. An estimated 2.95 billion people in 2019 used social media worldwide.
The widespread of the Coronavirus COVID-19 resulted with a tsunami of social
media. Most platforms were used to transmit relevant news, guidelines and
precautions to people. According to WHO, uncontrolled conspiracy theories and
propaganda are spreading faster than the COVID-19 pandemic itself, creating an
infodemic and thus causing psychological panic, misleading medical advises, and
economic disruption. Accordingly, discussions have been initiated with the
objective of moderating all COVID-19 communications, except those initiated
from trusted sources such as the WHO and authorized governmental entities. This
paper presents a large-scale study based on data mined from Twitter. Extensive
analysis has been performed on approximately one million COVID-19 related
tweets collected over a period of two months. Furthermore, the profiles of
288,000 users were analyzed including unique users profiles, meta-data and
tweets context. The study noted various interesting conclusions including the
critical impact of the (1) exploitation of the COVID-19 crisis to redirect
readers to irrelevant topics and (2) widespread of unauthentic medical
precautions and information. Further data analysis revealed the importance of
using social networks in a global pandemic crisis by relying on credible users
with variety of occupations, content developers and influencers in specific
fields. In this context, several insights and findings have been provided while
elaborating computing and non-computing implications and research directions
for potential solutions and social networks management strategies during crisis
periods.Comment: 11 pages, 10 figures, Journal Articl
Aprendizagem automática aplicada à deteção de pessoas baseada em radar
The present dissertation describes the development and implementation of a
radar-based system with the purpose of being able to detect people amidst
other objects that are moving in an indoor scenario. The detection methods
implemented exploit radar data that is processed by a system that includes the
data acquisition, the pre-processing of the data, the feature extraction, and the
application of these data to machine learning models specifically designed to
attain the objective of target classification.
Beyond the basic theoretical research necessary for its sucessful development,
the work contamplates an important component of software development
and experimental tests. Among others, the following topics were covered
in this dissertation: the study of radar working principles and hardware; radar
signal processing; techniques of clutter removal, feature exctraction, and data
clustering applied to radar signals; implementation and hyperparameter tuning
of machine learning classification systems; study of multi-target detection and
tracking methods.
The people detection application was tested in different indoor scenarios that
include a static radar and a radar dynamically deployed by a mobile robot. This
application can be executed in real time and perform multiple target detection
and classification using basic clustering and tracking algorithms. A study of
the effects of the detection of multiple targets in the performance of the application,
as well as an assessment of the efficiency of the different classification
methods is presented.
The envisaged applications of the proposed detection system include intrusion
detection in indoor environments and acquisition of anonymized data for
people tracking and counting in public spaces such as hospitals and schools.A presente dissertação descreve o desenvolvimento e implementação de um
sistema baseado em radar que tem como objetivo detetar e distinguir pessoas
de outros objetos que se movem num ambiente interior. Os métodos de deteção
e distinção exploram os dados de radar que são processados por um
sistema que abrange a aquisição e pré-processamento dos dados, a extração
de características, e a aplicação desses dados a modelos de aprendizagem
automática especificamente desenhados para atingir o objetivo de classificação
de alvos.
Além do estudo da teoria básica de radar para o desenvolvimento bem sucedido
desta dissertação, este trabalho contempla uma componente importante
de desenvolvimento de software e testes experimentais. Entre outros,
os seguintes tópicos foram abordados nesta dissertação: o estudo dos
princípios básicos do funcionamento do radar e do seu equipamento; processamento
de sinal do radar; técnicas de remoção de ruído, extração de
características, e segmentação de dados aplicada ao sinal de radar; implementação
e calibração de hiper-parâmetros dos modelos de aprendizagem
automática para sistemas de classificação; estudo de métodos de deteção e
seguimento de múltiplos alvos.
A aplicação para deteção de pessoas foi testada em diferentes cenários interiores
que incluem o radar estático ou transportado por um robot móvel.
Esta aplicação pode ser executada em tempo real e realizar deteção e classificação
de múltiplos alvos usando algoritmos básicos de segmentação e
seguimento. O estudo do impacto da deteção de múltiplos alvos no funcionamento
da aplicação é apresentado, bem como a avaliação da eficiência dos
diferentes métodos de classificação usados.
As possíveis aplicações do sistema de deteção proposto incluem a deteção
de intrusão em ambientes interiores e aquisição de dados anónimos para
seguimento e contagem de pessoas em espaços públicos tais como hospitais
ou escolas.Mestrado em Engenharia de Computadores e Telemátic
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