ssr-auth-syncnpm
Advisory published Updated
ssr-auth-sync is a confirmed malicious npm package (MAL-2026-5934) that steals credentials and exfiltrates sensitive data (malicious version 1.6.16). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in ssr-auth-sync (npm)
What this malware does
On require('ssr-auth-sync'), index.js loads lib/writer.js, which immediately fetches a base64-hidden URL (https://www.jsonkeeper.com/b/PJNZP, an anonymous pastebin-style host) via axios and passes the response body to eval. Just before the fetch, writer.js assembles an object containing the full process.env spread plus os.hostname(), os.userInfo().username, os.platform(), package version, and MAC addresses; this object is in lexical scope when eval runs, giving the attacker-served code a ready-to-exfiltrate payload of every secret in the installer's or CI's environment (AWS keys, npm tokens, CI secrets, etc.). A second covert channel is also present: a hex-decoding helper g() and an array hl containing hex-encoded strings that decode to 'axios', 'get', 'https://www.jsonkeeper.com/b/HY6M6', and 'then' — a parallel dropper hidden from string scanners. The package falsely advertises itself as an 'SSR auth sync' module while exporting a pino-shaped API and shipping pino-*.png brand assets, impersonating the popular pino logger to attract installs. Any project that adds this package to its dependency tree executes attacker-controlled code in its Node process the moment the module is required.
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for ssr-auth-sync (version 1.6.16).
If you installed it — respond
ssr-auth-sync is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If ssr-auth-sync was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks ssr-auth-sync-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.