The journal article referenced by the press release, titled "Does the Measured Abundance Suggest a Biological Origin for the Ancient Alkanes Preserved in a Martian Mudstone?" is at https://journals.sagepub.com/doi/epub/10.1177/15311074261417...

Life on ancient Mars should not be surprising: there would have been transfer of life on impact debris back and forth among Earth and Mars (and possibly Venus).