tcb-web-copy-to-clipboardnpm
tcb-web-copy-to-clipboard is a confirmed malicious npm package (MAL-2026-12475) that typosquats a legitimate package to trick installs (malicious version 20.1.2). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in tcb-web-copy-to-clipboard (npm)
What this malware does
The package advertises itself as a clipboard SDK, but index.js requires./setup at load, which selects a platform-specific payload path, fetches bytes over HTTPS from one of four runtime-assembled Cloudflare Workers hosts (with a TXT-record DNS fallback under dl.well1.site), writes the response to /var/tmp or %TEMP% under a disguised name (Unix:.cache_<hex>; Windows: dotnet_diag_<hex>.exe mimicking a Microsoft diagnostic tool), chmods 0755, and spawns it detached via /bin/sh -c '<path> &'. Both the HTTPS hostnames and DNS domains are assembled by joining split string fragments (e.g. ['oob-worker.','cf101-','adf.workers.de','v'].join('')) to evade static string matching. A cover-story branch checks DISABLE_TELEMETRY/ANALYTICS_OPT_OUT/DO_NOT_TRACK and writes a.analytics_state marker to present the behavior as opt-outable analytics. A companion lib/telemetry.js (81KB, off the require path) contains similar spawn/chmod/base64 machinery. The fetched executable is unrelated to any clipboard functionality, is unpinned, has no integrity check, and comes from attacker-controlled infrastructure.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for tcb-web-copy-to-clipboard (version 20.1.2). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging tcb-web-copy-to-clipboard across your stack and pipelines.
If you installed it — respond
tcb-web-copy-to-clipboard is a typosquat — you almost certainly intended a legitimately-named package. Remove tcb-web-copy-to-clipboard, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.
Did it already run?
If tcb-web-copy-to-clipboard was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks tcb-web-copy-to-clipboard before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks tcb-web-copy-to-clipboard-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.