If this package is installed
Remove it, treat the machine (or CI runner) as compromised, and rotate every secret, token and key it could access — from a different, clean machine.
Details
Source: amazon-inspector (3dcb85c2aba3b12a48393163cde3c6b1d3fa946d4f3745347791ae25ac216b86)
tellyo-colours@21.3.1 declares a runtime dependency on `abbishal-poc-as-dependency` with the wildcard version `"*"` in package.json, despite the README stating the package ships no code and no install scripts. On `npm install`, resolution of the wildcard range fetches whichever version the controller of that dependency name currently publishes and executes any lifecycle scripts (preinstall/install/postinstall) shipped in that transitive package. The shipped SCSS contains the canary string `--tostpro-canary: "test by abbishal"`, matching the dependency's author prefix and indicating the two artifacts are coordinated as a dependency-confusion proof-of-concept. The inert nature of the SCSS content and the absence of lifecycle scripts in this package do not mitigate the exposure — the manifest itself is sufficient to pull and run arbitrary code from the dependency on install.
Source: ghsa-malware (2db5060ac2f422cce03519639dde73e1e8e99347e74986455377462b6a16292e)
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.