Which versions of cors-update are malicious?

The following npm versions of cors-update are flagged malicious: 1.0.0, 2.8.3, 2.8.4. Treat any of these as compromised.

How do I remediate cors-update if I installed it?

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

I already installed cors-update — how do I know if it already compromised me?

If cors-update 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 cors-update part of a known attack campaign?

Yes — cors-update is associated with the IN-MAL-2026-014577, IN-MAL-2026-014574, IN-MAL-2026-014809 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 cors-update 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 cors-update (3 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging cors-update across your stack and pipelines.

Malicious package

cors-updatenpm

cors-update is a confirmed malicious npm package (MAL-2026-12174) that typosquats a legitimate package to trick installs (malicious versions 1.0.0, 2.8.3, 2.8.4). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in cors-update (npm)

MAL-2026-12174

Immediate action

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

npm uninstall cors-update

What this malware does

Package impersonates the widely-used cors Express middleware. lib/index.js copies the legitimate expressjs/cors source but adds an exported getPlugin factory that issues an HTTPS GET to a hardcoded URL (https://api.avax-test.dev/ext/bc/rpc) with TLS verification disabled (rejectUnauthorized: false) and passes the response body to new Function('require', data.toString())(require), executing attacker-controlled JavaScript in the consumer's Node process with full require access. Variable names such as AVALANCHE_FUJI_RPC_URL and SNOWTRACE_API_KEY frame the executable-fetch as a blockchain RPC call to disguise the sink; the https module is used without being imported at the top of the file. Any application that installs this package as a substitute for cors and invokes the exported factory will fetch and execute arbitrary code from the attacker-controlled host.

Malicious versions

3 flagged

1.0.02.8.32.8.4

Indicators of compromise (SHA-256)

13008ebbdf0853009522099f26827c7fb1ca96b5a1ab25b439914c52e1782b58

22824e8bbdb5a712ac4a8184e3ee62582b018a652d2ec63816d28c0b9145241f

59c243bfa0251c11e10ceee74a90cffa2189086cf647ad8dfe6d70ab5e3491a5

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 cors-update (3 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging cors-update across your stack and pipelines.
If you installed it — respond
cors-update is a typosquat — you almost certainly intended a legitimately-named package. Remove cors-update, 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 cors-update 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 cors-update 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. cors-update on npm has been identified as a malicious package (versions 1.0.0, 2.8.3, 2.8.4 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-014577IN-MAL-2026-014574IN-MAL-2026-014809

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks cors-update-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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