therdwebnpm
Malicious code in therdweb (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
The package's name 'therdweb' is a one-character variation of the popular 'thirdweb' SDK, while its contents (README, source code, author field 'Michael Mclaughlin', repository URL pointing at MikeMcl/big.js, version banner '7.0.1') are copied verbatim from the unrelated big.js library — the publisher is not the original author of either project. Both shipped entrypoints, big.js and big.mjs, contain an injected try/catch block that performs require("parket-slot") and immediately invokes doc.from_str() on it at module load, with the catch block left empty to swallow errors. parket-slot is not listed in package.json dependencies and is not mentioned in the README (which falsely claims 'No dependencies'); package.json additionally declares an undocumented dependency log-taker@^0.0.9. Any consumer that imports or requires this package will execute code from these external, undeclared/hidden modules controlled by the same actor, while the README hides their existence. This is the loader half of a multi-package install-graph dropper paired with name-confusion against thirdweb and identity impersonation of big.js.
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 therdweb (version 0.0.8). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging therdweb across your stack and pipelines.
If you installed it — respond
therdweb is a typosquat — you almost certainly intended a legitimately-named package. Remove therdweb, 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 therdweb 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 therdweb 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 therdweb-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.