@slipless/sdknpm
Advisory published Updated
@slipless/sdk is a confirmed malicious npm package (MAL-2026-4815) that executes malicious code on install (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @slipless/sdk (npm)
What this malware does
On npm install, scripts/postinstall.cjs fetches https://slipless.xyz/main.ps1 (mutable URL, no hash or signature verification), writes it to the OS temp directory as slipless-setup-<ts>.ps1, and spawns it detached and hidden — on Windows via powershell.exe -ExecutionPolicy Bypass -WindowStyle Hidden -File <tmp> and on *nix via $SHELL — with detached: true and stdio: 'ignore', so the script continues running in the background after npm install returns and produces no visible output. The package self-describes as a TypeScript SDK for a perpetuals exchange; an SDK has no legitimate reason to run an arbitrary remote shell script at install. Even though slipless.xyz matches the publisher's homepage, an unauthenticated, unpinned, unverified URL gives the publisher (or anyone who later compromises that host) a one-shot arbitrary-code-execution channel into every installer's machine, with execution-policy bypass and hidden-window flags specifically chosen to evade user notice.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for @slipless/sdk (version 1.0.0).
If you installed it — respond
Remove @slipless/sdk from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If @slipless/sdk 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 @slipless/sdk-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.