The recently attempted XZ Utils Backdoor (CVE-2024-3094) may not be an isolated case, as evidenced by a similarly credible takeover attempt intercepted by the OpenJS Foundation. The Open Source Security (OpenSSF) and OpenJS Foundations call on all open source maintainers to be vigilant for takeover attempts in the field of social engineering, to identify emerging early threat patterns and to take measures to protect their open source projects.