The zombies strike back: Towards client-side beef detection

A web browser is an application that comes bundled with every consumer operating system, including both desktop and mobile platforms. A modern web browser is complex software that has access to system-level features, includes various plugins and requires the availability of an Internet connection. Like any multifaceted software products, web browsers are prone to numerous vulnerabilities. Exploitation of these vulnerabilities can result in destructive consequences ranging from identity theft to network infrastructure damage. BeEF, the Browser Exploitation Framework, allows taking advantage of these vulnerabilities to launch a diverse range of readily available attacks from within the browser context. Existing defensive approaches aimed at hardening network perimeters and detecting common threats based on traffic analysis have not been found successful in the context of BeEF detection. This paper presents a proof-of-concept approach to BeEF detection in its own operating environment – the web browser – based on global context monitoring, abstract syntax tree fingerprinting and real-time network traffic analysis

Adiabatic contraction revisited: implications for primordial black holes

We simulate the adiabatic contraction of a dark matter (DM) distribution during the process of the star formation, paying particular attention to the phase space distribution of the DM particles after the contraction. Assuming the initial uniform density and Maxwellian distribution of DM velocities, we find that the number $n(r)$ of DM particles within the radius $r$ scales like $n(r) \propto r^{1.5}$, leading to the DM density profile $\rho\propto r^{-1.5}$, in agreement with the Liouville theorem and previous numerical studies. At the same time, the number of DM particles $\nu(r)$ with periastra smaller than $r$ is parametrically larger, $\nu(r) \propto r$, implying that many particles contributing at any given moment into the density $\rho(r)$ at small $r$ have very elongated orbits and spend most of their time at distances larger than $r$. This has implications for the capture of DM by stars in the process of their formation. As a concrete example we consider the case of primordial black holes (PBH). We show that accounting for very eccentric orbits boosts the amount of captured PBH by a factor of up to $2\times 10^3$ depending on the PBH mass, improving correspondingly the previously derived constraints on the PBH abundance.Comment: 8 pages, 3 figures, discussions added to the "Simulation of DM orbits" part, fig.3 with several DM densities. Revised version to match published versio

Constraints on primordial black holes as dark matter candidates from capture by neutron stars

We investigate constraints on primordial black holes (PBHs) as dark matter candidates that arise from their capture by neutron stars (NSs). If a PBH is captured by a NS, the star is accreted onto the PBH and gets destroyed in a very short time. Thus, mere observations of NSs put limits on the abundance of PBHs. High DM densities and low velocities are required to constrain the fraction of PBHs in DM. Such conditions may be realized in the cores of globular clusters if the latter are of a primordial origin. Assuming that cores of globular clusters possess the DM densities exceeding several hundred GeV/cm$^3$ would imply that PBHs are excluded as comprising all of the dark matter in the mass range $3\times 10^{18} \text{g} \lesssim m_\text{BH}\lesssim 10^{24} \text{g}$. At the DM density of $2\times 10^3$ GeV/cm$^3$ that has been found in simulations in the corresponding models, less than 5% of the DM may consist of PBH for these PBH masses.Comment: 7 pages, 2 figures, precise computation of dynamical friction added, accepted for publication in PR