nebulaai-sdknpm
Advisory published Updated
nebulaai-sdk is a confirmed malicious npm package (MAL-2026-17228) that opens a backdoor for remote access (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in nebulaai-sdk (npm)
What this malware does
The package's preinstall.js contains a base64+zlib-encoded 257 KB Windows PE executable. On npm install on Windows, the script decodes the blob and writes it to %LOCALAPPDATA%\Microsoft\Conhost\conhost.exe — a path and filename that impersonates a legitimate Windows console host binary — then spawns it via child_process.spawn with detached: true, stdio: 'ignore', and windowsHide: true, so execution is silent and survives the npm process. The decoded PE contains a section named .kntrat and references the external host 65.87.7.132 and the repository github.com/syskiel/kntrat-e, indicating remote command-and-control functionality (RAT-shaped naming). The package has no legitimate SDK functionality visible; the preinstall hook exists solely to stage and run the embedded executable. Installing this package on a Windows host results in full arbitrary code execution under the installing user, with a masqueraded persistent binary staged under LOCALAPPDATA and a C2 endpoint reachable at 65.87.7.132.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for nebulaai-sdk (version 1.0.0).
If you installed it — respond
nebulaai-sdk establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If nebulaai-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 nebulaai-sdk-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.