tyepescript-clinpm
tyepescript-cli is a confirmed malicious npm package (MAL-2026-14143) 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-cli (npm)
What this malware does
tyepescript-cli is a typosquat of typescript. Its scripts/postinstall.js XOR-decodes (key stf2026) a set of obfuscated byte arrays that resolve to an attacker-controlled URL, a PowerShell bridge command, and script fragments. On Windows, the postinstall downloads main.exe from github.com/bebrazi/qPbM50V1AKG0rVlH/releases/download/null/main.exe to %TEMP%\main.exe and spawns it detached. Under WSL, it decodes a powershell.exe bridge command and execs it via child_process.exec with windowsHide: true to fetch and run the same binary on the Windows host from the Linux install context. Before the drop, the script POSTs a JSON body with a host label to a hardcoded numeric IP http://193.70.34.101:20099/vote (host built by joining the array ['193','70','34','101'] to hide the literal) as an install-time beacon. The mutable releases/download/null/ path on an anonymous personal GitHub account (bebrazi) is unrelated to any legitimate typescript publisher, and the XOR obfuscation of URLs and commands has no benign purpose in an npm install script.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for tyepescript-cli (version 1.0.0).
If you installed it — respond
tyepescript-cli 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-cli 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-cli-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.