@decoopus/claude-setup@1.0.0
OpenSSF/OSV Malicious Advisory
imported 22h ago · by OpenSSF/OSVOpenSSF/OSV advisory MAL-2026-18054 confirms this npm version as malicious.
Advisory
MAL-2026-18054
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in @decoopus/claude-setup (npm)
Details
The CLI prompts the user for an Anthropic API key (sk-ant-...) and writes it, together with a hardcoded gateway base URL https://api-anthropic.help, into Claude Desktop's configuration in every location it can reach: Windows registry policies at HKCU\SOFTWARE\Policies\Claude via reg.exe, macOS managed preferences for com.anthropic.claudefordesktop via `defaults write`, claude_desktop_config.json, and all profile JSON files under configLibrary. The domain api-anthropic.help is a lookalike of api.anthropic.com and is not operated by Anthropic, so after setup every Claude Desktop request — including the user's API key and all prompt/response traffic — is transparently relayed to an attacker-controlled endpoint. The package also kills running Claude.exe/Claude processes and recursively deletes Session Storage, Local Storage, IndexedDB, cookies, and host-creds/custom3p/probe-cache files across standard, Claude-3p, and Windows Store MSIX install locations, then relaunches Claude Desktop so the next authentication flow is forced through the attacker gateway. A comment references a prior gateway host api.vokes.in that the package explicitly overwrites, and the shipped DEFAULT_MODELS list contains fabricated model names (claude-fable-5-1, claude-opus-5-5, claude-sonnet-5-5, claude-haiku-5-5) under a 'Claude Max 20x · API Usage Billing' label that do not correspond to Anthropic's product lineup, consistent with an iterated phishing/relay operation.
## Source: ghsa-malware (e9c714cd8ba4dd623d5570083b71cdbc76991794df7b81833c282793dddfcbbd) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Independent LPM AI assessment
CleanIndependent AI assessment: clean. LPM AI assessed this version as clean; the assessments disagree.
The reviewed source implements an explicitly invoked gateway setup tool, with the destination shown to the user and configurable. Its publisher-selected default endpoint merits attention, but the source supports the stated third-party gateway purpose and shows no concealed credential transfer or automatic install-time action.
Static reason
No blocking static signals were detected.
Trigger
A user runs the setup CLI and supplies or enters a gateway API key.
Impact
Claude Desktop requests use the configured gateway; the inspected code does not secretly send the entered key elsewhere.
Mechanism
The CLI displays the gateway URL and saves that URL and the supplied key in Claude Desktop settings.
AI rationale
The reviewed source implements an explicitly invoked gateway setup tool, with the destination shown to the user and configurable. Its publisher-selected default endpoint merits attention, but the source supports the stated third-party gateway purpose and shows no concealed credential transfer or automatic install-time action.
Network endpoints1
api-anthropic.help
Independent scan evidence
public snapshotAI called this Clean at 91.0% confidence as Benign with low false-positive risk.
Evidence for AI clean decision
- The manifest provides a CLI entrypoint and only a start script; it declares no install lifecycle hook.
- The CLI prompts for an API key, displays the gateway URL, and stores the supplied key and URL in Claude Desktop settings as part of its setup function.
Evidence against
- The CLI selects https://api-anthropic.help as its default gateway, though it displays the destination and accepts a URL override.
Behavioral surface
ChildProcessEnvironmentVarsFilesystemShell
UrlStrings
Source & flagged code
5 flagged · loading sourcepackage.jsonView file
15"scripts": {
"start": "node ./bin/cli.js"
},
"keywords": [
"claude",
"claude-deskt
High
Suspicious Lifecycle Evidence
The manifest provides a CLI entrypoint and only a start script; it declares no install lifecycle hook.
package.jsonView on unpkg · L15bin/cli.jsView file
617if (!apiKey) {
log(`${colors.cyan}Please enter your API Key to configure Claude Desktop:${colors.reset}`);
apiKey = await askQuestion(`${colors.bold}API Key: ${colors.res
High
Ai Review Evidence
The CLI prompts for an API key, displays the gateway URL, and stores the supplied key and URL in Claude Desktop settings as part of its setup function.
bin/cli.jsView on unpkg · L617630log(` Gateway Base URL : ${colors.cyan}${gatewayUrl}${colors.reset}`);
log(` Auth Scheme : ${colors.cyan}${authScheme}${colors.reset}`);
log(` API Key : ${co
High
Ai Review Evidence
Findings
5 High1 Medium3 Low
HighSuspicious Lifecycle Evidencepackage.json
HighAi Review Evidencebin/cli.js
HighAi Review Evidencebin/cli.js
HighAi Review Evidencebin/cli.js
HighAi Review Evidencebin/cli.js
MediumEnvironment Vars
LowScripts Present
LowFilesystem
LowUrl Strings
Affected versions and remediation
This report applies to @decoopus/claude-setup@1.0.0.
See all versions of @decoopus/claude-setup for other recorded verdicts.
- Avoid installing @decoopus/claude-setup@1.0.0. Remove it from direct dependencies and check your lockfile for transitive copies.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.
- If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.
Evidence last updated: .
Source advisory published: .
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