Which versions of postcss-initialize-plugin are malicious?

The following npm versions of postcss-initialize-plugin are flagged malicious: 3.0.4. Treat any of these as compromised.

How do I remediate postcss-initialize-plugin if I installed it?

postcss-initialize-plugin is a typosquat — you almost certainly intended a legitimately-named package. Remove postcss-initialize-plugin, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.

I already installed postcss-initialize-plugin — how do I know if it already compromised me?

If postcss-initialize-plugin 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 postcss-initialize-plugin part of a known attack campaign?

Yes — postcss-initialize-plugin is associated with the IN-MAL-2026-017640 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 postcss-initialize-plugin 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 postcss-initialize-plugin (version 3.0.4). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging postcss-initialize-plugin across your stack and pipelines.

Malicious package

postcss-initialize-pluginnpm

postcss-initialize-plugin is a confirmed malicious npm package (MAL-2026-13957) that typosquats a legitimate package to trick installs (malicious version 3.0.4). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in postcss-initialize-plugin (npm)

MAL-2026-13957

Immediate action

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

npm uninstall postcss-initialize-plugin

What this malware does

postcss-initialize-plugin is a typosquat of postcss-initial. Its README, repository URL, and author metadata are copied verbatim from maximkoretskiy/postcss-initial, and the legitimate plugin source is present, but index.js has an appended obfuscator.io payload (rotating string array _0x240a, control-flow flattening) that runs on require. Deobfuscation recovers imports of http, https, zlib, and child_process, along with a hardcoded list of Ethereum RPC endpoints (eth.drpc.org, ethereum-rpc.publicnode.com, 1rpc.io/eth, blastapi.io, plus process.env.ETH_RPC_URL) and Etherscan-style txlist query parameters for a hardcoded address beginning 0xa322E5f3. On load the payload queries these endpoints for transaction data tied to that address, decompresses the returned bytes with zlib (gzip/deflate/br), stashes require and module on global, and passes the decoded content to child_process.spawn — giving the operator of that Ethereum address arbitrary code execution on any machine that installs or requires this package. A legitimate PostCSS plugin has no reason to contact Ethereum RPCs, spawn child processes, or bury its logic behind a string-array decoder.

Malicious versions

1 flagged

3.0.4

Indicators of compromise (SHA-256)

c75b316d71a07c70e033fe47d5a3efbd6c3dbccb3b1ae8466a4d325c0d1ada79

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 postcss-initialize-plugin (version 3.0.4). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging postcss-initialize-plugin across your stack and pipelines.
If you installed it — respond
postcss-initialize-plugin is a typosquat — you almost certainly intended a legitimately-named package. Remove postcss-initialize-plugin, 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 postcss-initialize-plugin 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 postcss-initialize-plugin 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. postcss-initialize-plugin on npm has been identified as a malicious package (version 3.0.4 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-017640

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks postcss-initialize-plugin-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

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