JFrog Security Research said on October 26 that it found 42 GitHub repositories, owned by 11 legitimate owners, armed with hidden malicious code. The repositories link to an npm package campaign that JFrog calls testmetest. Each held a payload file of about 12.9 to 13.7 MB. GitHub code search did not index files that large, and the contents API could not return them. JFrog's first search found 26 repositories. Checking each repository's file tree directly raised the count to 42.
The repositories also held startup hooks for AI coding tools and code editors. JFrog said the hidden code is built to publish more malicious npm releases. SafeDep, which first reported on the npm side on October 22, said at the time that it had not confirmed compromised third-party packages or victims. JFrog did not decrypt the data files in an attacker-owned repository, so it cannot say who the victims are or how many systems are affected. It also does not claim the original Miasma operators are responsible.
JFrog's own first search missed these files, so checks that rely on GitHub code search can miss this kind of attack. JFrog also found hooks that start hidden code when a supported tool opens a project, so teams that open cloned repositories in such tools face a real path to running it.