Scientific American also has a good synopsis). The work on analysis has not yet been published in the scientific journals, though papers are expected to come out soon, so we don't have the whole story yet. I am in general reluctant to report on non-published data, but given that this news is out there, I think it's important to give people the background.
The signal was detected as part of a set of observations of the star Proxima Centauri (usually just called Proxima) in the summer of 2019. It was being done as part of Breakthrough Listen, an initiative to observe the nearest one million stars to our Sun using radio telescopes across the world to look for signals of alien intelligence.