NA62 is successfully running in the North Area of the CERN SPS
with the main goal of measuring the $BR(K^+ \to \pi^+ \nu \overline{\nu})$ with $10\%$ accuracy.
Owing to the high beam energy and high beam intensity, the long decay volume and the hermetic detector coverage,
NA62 also has the opportunity to directly search for a
plethora of hidden-sector particles, both in visible or invisible final states.
A large variety of searches for hidden sector particles can be performed using kaon decays
and broad and rich physics programme is being proposed for the 2021-2023 data taking, including
$\sim 10^{18}$ protons-on-target (pot) collected when the experiment is operated in dump mode.
We will detail the status of the first analysis based on the $2\times 10^{15}$ pot already collected in dump mode.