Which versions of checkmarx-claude-cache are malicious?

The following npm versions of checkmarx-claude-cache are flagged malicious: 1.0.0, 1.0.1. Treat any of these as compromised.

How do I remediate checkmarx-claude-cache if I installed it?

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

I already installed checkmarx-claude-cache — how do I know if it already compromised me?

If checkmarx-claude-cache was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Is checkmarx-claude-cache part of a known attack campaign?

Yes — checkmarx-claude-cache is associated with the IN-MAL-2026-007761, IN-MAL-2026-009334 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 checkmarx-claude-cache across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for checkmarx-claude-cache (2 malicious versions).

Malicious package

checkmarx-claude-cachenpm

Advisory published Jun 29, 2026Updated Jul 9, 2026

checkmarx-claude-cache is a confirmed malicious npm package (MAL-2026-6576) that typosquats a legitimate package to trick installs (malicious versions 1.0.0, 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in checkmarx-claude-cache (npm)

MAL-2026-6576

Immediate action

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

npm uninstall checkmarx-claude-cache

What this malware does

When the CLI runs (the documented npx checkmarx-claude-cache invocation pattern), bin/cli.js performs an HTTPS GET to a hardcoded URL on a lookalike host — https://download.east-1.us.com/release/{windows,mac}/install — and pipes the response body directly into a shell interpreter via execSync: bash on macOS/Linux and powershell -NoProfile -NonInteractive -Command - on Windows. The response bytes are opaque, unpinned, and not verified via hash or signature, so whatever the server returns at fetch time runs on the installer's machine with the user's privileges. The request uses a forged curl/PowerShell User-Agent to blend with legitimate installer traffic. The package name and README impersonate Checkmarx (a security vendor) and Anthropic's Claude product to make the npx invocation appear trustworthy; neither vendor publishes this package, and download.east-1.us.com mimics AWS region naming but has no relation to Checkmarx's real infrastructure at checkmarx.com. The package contains no other functionality — the brand impersonation is the lure and the remote fetch-and-exec is the payload.

Malicious versions

2 flagged

1.0.01.0.1

Indicators of compromise (SHA-256)

4cbdcac8329a6ad9662ef7af8e0f68cd616f5451dc0a1fce9d2bcab5a7943c8a

26a16e61d88e467ada75205ee93a9339cdf2fb65f3ded068282b4d83b6cb05e9

Detection & response playbook

Typosquat

Find it
Search your lockfiles and build artifacts for checkmarx-claude-cache (2 malicious versions).
If you installed it — respond
checkmarx-claude-cache is a typosquat — you almost certainly intended a legitimately-named package. Remove checkmarx-claude-cache, 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 checkmarx-claude-cache was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. checkmarx-claude-cache on npm has been identified as a malicious package (versions 1.0.0, 1.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-007761IN-MAL-2026-009334

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks checkmarx-claude-cache-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