@withgoogle/stitch-sdknpm
@withgoogle/stitch-sdk is a confirmed malicious npm package (MAL-2026-6256) that steals credentials and exfiltrates sensitive data (malicious versions 0.1.1, 0.1.2, 0.1.3…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @withgoogle/stitch-sdk (npm)
What this malware does
@withgoogle/stitch-sdk is a scope-squatting package on npm that impersonates Google's Stitch AI design tool SDK. The attacker registered the @withgoogle scope to mimic Google's withgoogle.com domain and published versions 0.1.1 and 0.1.2 under the account maximus-mcmillan on June 19, 2026. The package runs a credential harvester from a preinstall hook (scripts/preinstall.js) and an identical CLI binary (bin/cli.js). On install it scrapes email addresses and credentials from Claude Code authentication, git config, ~/.git-credentials, ~/.ssh/*.pub, the GitHub CLI, ~/.npmrc, and ~/.docker/config.json, then exfiltrates them to https://stitch-production.org/api/v1 over HTTPS with TLS verification disabled (rejectUnauthorized: false). The code is unobfuscated and relies on the trust of the @withgoogle scope name.
Package is published under the @withgoogle npm scope but the package.json author is 'Maximus McMillan' with repository github.com/maximus-mcmillan/stitch-sdk — there is no Google affiliation. scripts/preinstall.js runs automatically on npm install and enumerates installer-side identity and credential sources: git config user.email (--global/--system), ~/.gitconfig, ~/.config/git/config, ~/.git-credentials (which stores plaintext https://user:token@host entries), ~/.ssh/*.pub, gh api user, claude auth status, npm config get email, ~/.npmrc (npm auth tokens), and ~/.docker/config.json (registry auth). The harvested values are HTTP-GET'd to https://stitch-production.org/api/v1?src=...&user=... with TLS verification explicitly disabled (rejectUnauthorized:false at scripts/preinstall.js:46) to ensure delivery. The hardcoded C2 base URL is at scripts/preinstall.js:26 (const STITCH_SERVER_BASE = 'https://stitch-production.org/api/v1'). The combination of @withgoogle scope impersonation, preinstall lifecycle execution, enumeration of canonical credential-file paths, and exfiltration to an attacker-controlled host with TLS verification disabled is a deliberate supply-chain attack against any developer or build system that installs this package.
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
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for @withgoogle/stitch-sdk (5 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @withgoogle/stitch-sdk across your stack and pipelines.
If you installed it — respond
@withgoogle/stitch-sdk 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 @withgoogle/stitch-sdk was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks @withgoogle/stitch-sdk before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
- SafeDep · finder
Detect & block this
O3 blocks @withgoogle/stitch-sdk-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.