IAVS: Intelligent Active Network Vulnerability Scanner

Network security needs to be assured through runtime active evaluating and assessment. However, active vulnerability scanners suffer from serious deficiencies such as heavy scan traffic during the reconnaissance phase, uncertainty in the environment, and heavy reliance on experts. Generating a blind heavy load of attack packets not only causes usage of network resources, but it also increases the probability of detection by target defense systems and causes failure in finding vulnerabilities. Furthermore, environmental uncertainty increases pointless attempts of vulnerability scanners, which wastes time. Utilizing a decision-making method devised for uncertainty conditions, we present Intelligent Active Network Vulnerability Scanner (IAVS). IAVS is implemented as an extension on Hail Mary, the automatic execution mechanism in the Metasploit toolkit. IAVS learns from previous vulnerability exploitation attempts to select exploit codes purposefully. IAVS not only reduces the role of experts in the process of vulnerability testing, but it also decreases the volume of scanning requests during the reconnaissance phase by integrating the reconnaissance and exploitation phases. Our experimental results indicate a successful decrease in failed attempts. It is also demonstrated that improvements in the results of IAVS correspond directly to the rate of similarity among different vulnerabilities in systems of the target network; that is, the higher the similarity, the better the results of IAVS. Our experiments compared the results of IAVS and those of Hail Mary without the IAVS extension; these results show that IAVS improved Hail Marys successful attempts by around 37%.

High-speed quantitative optical imaging of absolute metabolism in the rat cortex.

Significance: Quantitative measures of blood flow and metabolism are essential for improved assessment of brain health and response to ischemic injury. Aim: We demonstrate a multimodal technique for measuring the cerebral metabolic rate of oxygen ( CMRO2 ) in the rodent brain on an absolute scale ( μM O2/min ). Approach: We use laser speckle imaging at 809 nm and spatial frequency domain imaging at 655, 730, and 850 nm to obtain spatiotemporal maps of cerebral blood flow, tissue absorption ( μa ), and tissue scattering ( μs' ). Knowledge of these three values enables calculation of a characteristic blood flow speed, which in turn is input to a mathematical model with a "zero-flow" boundary condition to calculate absolute CMRO2 . We apply this method to a rat model of cardiac arrest (CA) and cardiopulmonary resuscitation. With this model, the zero-flow condition occurs during entry into CA. Results: The CMRO2 values calculated with our method are in good agreement with those measured with magnetic resonance and positron emission tomography by other groups. Conclusions: Our technique provides a quantitative metric of absolute cerebral metabolism that can potentially be used for comparison between animals and longitudinal monitoring of a single animal over multiple days. Though this report focuses on metabolism in a model of ischemia and reperfusion, this technique can potentially be applied to far broader types of acute brain injury and whole-body pathological occurrences

High-speed spatial frequency domain imaging of rat cortex detects dynamic optical and physiological properties following cardiac arrest and resuscitation.

Quantifying rapidly varying perturbations in cerebral tissue absorption and scattering can potentially help to characterize changes in brain function caused by ischemic trauma. We have developed a platform for rapid intrinsic signal brain optical imaging using macroscopically structured light. The device performs fast, multispectral, spatial frequency domain imaging (SFDI), detecting backscattered light from three-phase binary square-wave projected patterns, which have a much higher refresh rate than sinusoidal patterns used in conventional SFDI. Although not as fast as "single-snapshot" spatial frequency methods that do not require three-phase projection, square-wave patterns allow accurate image demodulation in applications such as small animal imaging where the limited field of view does not allow single-phase demodulation. By using 655, 730, and 850 nm light-emitting diodes, two spatial frequencies ([Formula: see text] and [Formula: see text]), three spatial phases (120 deg, 240 deg, and 360 deg), and an overall camera acquisition rate of 167 Hz, we map changes in tissue absorption and reduced scattering parameters ([Formula: see text] and [Formula: see text]) and oxy- and deoxyhemoglobin concentration at [Formula: see text]. We apply this method to a rat model of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) to quantify hemodynamics and scattering on temporal scales ([Formula: see text]) ranging from tens of milliseconds to minutes. We observe rapid concurrent spatiotemporal changes in tissue oxygenation and scattering during CA and following CPR, even when the cerebral electrical signal is absent. We conclude that square-wave SFDI provides an effective technical strategy for assessing cortical optical and physiological properties by balancing competing performance demands for fast signal acquisition, small fields of view, and quantitative information content