  IGR J14257-6117 is an unclassified source in the hard X-ray catalogues.
Optical follow-ups suggest it could be a Cataclysmic Variable of the magnetic
type. We present the first high S/N X-ray observation performed by \XMM\ at
0.3--10 keV, complemented with 10--80 keV coverage by \Swift/BAT, aimed at
revealing the source nature. We detected for the first time a fast periodic
variability at 509.5\,s and a longer periodic variability at 4.05\,h, ascribed
to the white dwarf (WD) spin and binary orbital periods, respectively. These
unambiguously identify IGR J14257-6117 as a magnetic CV of the Intermediate
Polar (IP) type. The energy resolved light curves at both periods reveal
amplitudes decreasing with increasing energy, with the orbital modulation
reaching $\sim100\%$ in the softest band. The energy spectrum shows optically
thin thermal emission with an excess at the iron complex, absorbed by two dense
media (${\rm N_{H}\sim10^{22-23}\,cm^{-2}}$), partially covering the X-ray
source. These are likely localised in the magnetically confined accretion flow
above the WD surface and at the disc rim, producing the energy dependent spin
and orbital variabilities, respectively. IGR J14257-6117, joins the group of
strongest orbitally modulated IPs now counting four systems. Drawing
similarities with low-mass X-ray binaries displaying orbital dips, these IPs
should be seen at large orbital inclinations allowing azimuthally extended
absorbing material fixed in the binary frame to intercept the line of sight.
For IGR J14257-6117, we estimate ($50^o\,\lesssim\,i\,\lesssim\,70^o$). Whether
also the mass accretion rate plays a role in the large orbital modulations in
IPs cannot be established with the present data.
