tyepescript-corenpm
Advisory published Updated
tyepescript-core is a confirmed malicious npm package (MAL-2026-14144) 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 tyepescript-core (npm)
What this malware does
Package name 'tyepescript-core' is a typosquat of 'typescript'; the module itself exports an empty stub. scripts/postinstall.js XOR-decodes byte arrays (key 'stf2026') to reconstruct a download URL and shell command at runtime, fetches an opaque Windows binary to %TEMP%\main.exe, and spawns it detached with stdio ignored. On WSL/virtualized-Linux hosts, a second XOR-decoded 'bridge' command is passed to child_process.exec to reach the Windows host. The same postinstall also POSTs a JSON body containing the resolved platform label to http://193.70.34.101:20099/vote, with the bare-IP host assembled at runtime from a string array to hide the literal. Result: arbitrary attacker-controlled code execution on the installer's machine at 'npm install' time, plus an install beacon to attacker infrastructure.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for tyepescript-core (version 1.0.0).
If you installed it — respond
tyepescript-core 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 tyepescript-core 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 tyepescript-core-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.