chai-as-renderednpm
Advisory published Updated
chai-as-rendered is a confirmed malicious npm package (MAL-2026-12348) that opens a backdoor for remote access (malicious version 1.2.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in chai-as-rendered (npm)
What this malware does
Typosquat of chai-as-promised. The package's exported middleware spawns a detached child process (lib/caller.js) that fetches a JSON payload from a base64-obfuscated jsonstorage.net URL (https://api.jsonstorage.net/v1/json/2ef8c758-a96f-459e-b036-b3b90379a165/f89e8264-86c2-4684-94da-c3f82d59370f) and evaluates the returned.cookie string via new Function.constructor("require", s)(require), giving the fetched code full require access on the installer's host. The remote URL and request headers are stored as base64 strings under fake process.env names (DEV_API_KEY, DEV_SECRET_KEY, DEV_SECRET_VALUE) and decoded with atob() at runtime to conceal the destination. The package name and keywords (fast, logger, stream, json) impersonate pino while the package name typosquats chai-as-promised.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for chai-as-rendered (version 1.2.0).
If you installed it — respond
chai-as-rendered 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 chai-as-rendered 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
- ReversingLabs · finder
Detect & block this
O3 blocks chai-as-rendered-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.