2,301 research outputs found
DeltaPhish: Detecting Phishing Webpages in Compromised Websites
The large-scale deployment of modern phishing attacks relies on the automatic
exploitation of vulnerable websites in the wild, to maximize profit while
hindering attack traceability, detection and blacklisting. To the best of our
knowledge, this is the first work that specifically leverages this adversarial
behavior for detection purposes. We show that phishing webpages can be
accurately detected by highlighting HTML code and visual differences with
respect to other (legitimate) pages hosted within a compromised website. Our
system, named DeltaPhish, can be installed as part of a web application
firewall, to detect the presence of anomalous content on a website after
compromise, and eventually prevent access to it. DeltaPhish is also robust
against adversarial attempts in which the HTML code of the phishing page is
carefully manipulated to evade detection. We empirically evaluate it on more
than 5,500 webpages collected in the wild from compromised websites, showing
that it is capable of detecting more than 99% of phishing webpages, while only
misclassifying less than 1% of legitimate pages. We further show that the
detection rate remains higher than 70% even under very sophisticated attacks
carefully designed to evade our system.Comment: Preprint version of the work accepted at ESORICS 201
A population of luminous accreting black holes with hidden mergers
Major galaxy mergers are thought to play an important part in fuelling the
growth of supermassive black holes. However, observational support for this
hypothesis is mixed, with some studies showing a correlation between merging
galaxies and luminous quasars and others showing no such association. Recent
observations have shown that a black hole is likely to become heavily obscured
behind merger-driven gas and dust, even in the early stages of the merger, when
the galaxies are well separated (5 to 40 kiloparsecs). Merger simulations
further suggest that such obscuration and black-hole accretion peaks in the
final merger stage, when the two galactic nuclei are closely separated (less
than 3 kiloparsecs). Resolving this final stage requires a combination of
high-spatial-resolution infrared imaging and high-sensitivity hard-X-ray
observations to detect highly obscured sources. However, large numbers of
obscured luminous accreting supermassive black holes have been recently
detected nearby (distances below 250 megaparsecs) in X-ray observations. Here
we report high-resolution infrared observations of hard-X-ray-selected black
holes and the discovery of obscured nuclear mergers, the parent populations of
supermassive-black-hole mergers. We find that obscured luminous black holes
(bolometric luminosity higher than 2x10^44 ergs per second) show a significant
(P<0.001) excess of late-stage nuclear mergers (17.6 per cent) compared to a
sample of inactive galaxies with matching stellar masses and star formation
rates (1.1 per cent), in agreement with theoretical predictions. Using
hydrodynamic simulations, we confirm that the excess of nuclear mergers is
indeed strongest for gas-rich major-merger hosts of obscured luminous black
holes in this final stage.Comment: To appear in the 8 November 2018 issue of Nature. This is the
authors' version of the wor
Free-hand sketch synthesis with deformable stroke models
We present a generative model which can automatically summarize the stroke
composition of free-hand sketches of a given category. When our model is fit to
a collection of sketches with similar poses, it discovers and learns the
structure and appearance of a set of coherent parts, with each part represented
by a group of strokes. It represents both consistent (topology) as well as
diverse aspects (structure and appearance variations) of each sketch category.
Key to the success of our model are important insights learned from a
comprehensive study performed on human stroke data. By fitting this model to
images, we are able to synthesize visually similar and pleasant free-hand
sketches
Two loop electroweak corrections to and in the B-LSSM
The rare decays and are important to research new physics beyond standard model. In
this work, we investigate two loop electroweak corrections to and in the minimal
supersymmetric extension of the SM with local gauge symmetry (B-LSSM),
under a minimal flavor violating assumption for the soft breaking terms. In
this framework, new particles and new definition of squarks can affect the
theoretical predictions of these two processes, with respect to the MSSM.
Considering the constraints from updated experimental data, the numerical
results show that the B-LSSM can fit the experimental data for the branching
ratios of and . The
results of the rare decays also further constrain the parameter space of the
B-LSSM.Comment: 33 pages, 9 figures, Published in EPJ
Evidence for an excess of B -> D(*) Tau Nu decays
Based on the full BaBar data sample, we report improved measurements of the
ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B -> D(*) l Nu), where l is either e or
mu. These ratios are sensitive to new physics contributions in the form of a
charged Higgs boson. We measure R(D) = 0.440 +- 0.058 +- 0.042 and R(D*) =
0.332 +- 0.024 +- 0.018, which exceed the Standard Model expectations by 2.0
sigma and 2.7 sigma, respectively. Taken together, our results disagree with
these expectations at the 3.4 sigma level. This excess cannot be explained by a
charged Higgs boson in the type II two-Higgs-doublet model. We also report the
observation of the decay B -> D Tau Nu, with a significance of 6.8 sigma.Comment: Expanded section on systematics, text corrections, improved the
format of Figure 2 and included the effect of the change of the Tau
polarization due to the charged Higg
Controlling mode orientations and frequencies in levitated cavity optomechanics
Cavity optomechanics offers quantum cooling, quantum control and measurement
of small mechanical oscillators. However the optical backactions that underpin
quantum control can significantly disturb the oscillator modes: mechanical
frequencies are shifted by the optical spring effect and light-matter
hybridisation in strong coupling regimes; mechanical modes hybridise with each
other via the cavity mode. This is even more pertinent in the field of
levitated optomechanics, where optical trapping fully determines the mechanical
modes and their frequencies. Here, using the coherent-scattering (CS) set-up
that allowed quantum ground state cooling of a levitated nanoparticle, we show
that -- when trapping away from a node of the cavity standing wave -- the CS
field opposes optical spring shifts and mechanical mode hybridisation. At an
optimal cancellation point, independent of most experimental parameters, we
demonstrate experimentally that it is possible to strongly cavity cool and
control the {\em unperturbed} modes. Suppression of the cavity-induced mode
hybridisation in the plane is quantified by measuring the
correlation spectra which are seen to always be
anti-correlated except at the cancellation point where they become
uncorrelated. The findings have implications for directional force sensing
using CS set-ups
A search for the decay modes B+/- to h+/- tau l
We present a search for the lepton flavor violating decay modes B+/- to h+/-
tau l (h= K,pi; l= e,mu) using the BaBar data sample, which corresponds to 472
million BBbar pairs. The search uses events where one B meson is fully
reconstructed in one of several hadronic final states. Using the momenta of the
reconstructed B, h, and l candidates, we are able to fully determine the tau
four-momentum. The resulting tau candidate mass is our main discriminant
against combinatorial background. We see no evidence for B+/- to h+/- tau l
decays and set a 90% confidence level upper limit on each branching fraction at
the level of a few times 10^-5.Comment: 15 pages, 7 figures, submitted to Phys. Rev.
Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δϕ modulation for all ΣETPb ranges and particle pT
Study of the reaction e^{+}e^{-} -->J/psi\pi^{+}\pi^{-} via initial-state radiation at BaBar
We study the process with
initial-state-radiation events produced at the PEP-II asymmetric-energy
collider. The data were recorded with the BaBar detector at center-of-mass
energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454
. We investigate the mass
distribution in the region from 3.5 to 5.5 . Below 3.7
the signal dominates, and above 4
there is a significant peak due to the Y(4260). A fit to
the data in the range 3.74 -- 5.50 yields a mass value
(stat) (syst) and a width value (stat)(syst) for this state. We do not
confirm the report from the Belle collaboration of a broad structure at 4.01
. In addition, we investigate the system
which results from Y(4260) decay
Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector
The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV
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