What does the tcb-web-copy-to-clipboard malware do?

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_ ; Windows: dotnet_diag_ .exe mimicking a Microsoft diagnostic tool), chmods 0755, and spawns it detached via /bin/sh -c ' &'. 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 c

Which versions of tcb-web-copy-to-clipboard are malicious?

The following npm versions of tcb-web-copy-to-clipboard are flagged malicious: 20.1.2. Treat any of these as compromised.

How do I remediate tcb-web-copy-to-clipboard if I installed it?

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.

I already installed tcb-web-copy-to-clipboard — how do I know if it already compromised me?

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.

Is tcb-web-copy-to-clipboard part of a known attack campaign?

Yes — tcb-web-copy-to-clipboard is associated with the IN-MAL-2026-014677 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find tcb-web-copy-to-clipboard across my projects, lockfiles, and CI pipelines?

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.

Malicious package

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)

MAL-2026-12475

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall tcb-web-copy-to-clipboard

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.

Malicious versions

1 flagged

20.1.2

Indicators of compromise (SHA-256)

e17b4feb97874ea6bf112238baf911ef3ebb815f12034b726c8b1a5d1705adbb

Detection & response playbook

Typosquat

Find 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

No. tcb-web-copy-to-clipboard on npm has been identified as a malicious package (version 20.1.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-014677

References

npmjs.com

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.

Malware detection Runtime egress monitoring

Explore

All malware advisories How O3 detects malware Vulnerability database