solidity-testing-utilsnpm
solidity-testing-utils is a confirmed malicious npm package (MAL-2026-14375) that opens a backdoor for remote access (malicious version 1.2.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in solidity-testing-utils (npm)
What this malware does
Package presents itself as a chai/solidity testing helper and pino-style logger, but its exported middleware factory in index.js silently spawns lib/caller.js via child_process.spawn('node', [...], { detached: true, stdio: 'ignore' }) followed by child.unref(). lib/caller.js base64-decodes a hardcoded URL to https://api.jsonstorage.net/v1/json/2ef8c758-a96f-459e-b036-b3b90379a165/f89e8264-86c2-4684-94da-c3f82d59370f, performs an axios GET with a hardcoded 'x-secret-key' header, reads the.data.cookie field from the response, and passes it to new Function.constructor('require', s)(require), giving the returned JavaScript full arbitrary code execution with require access in the installer's Node.js process. The destination is an attacker-controlled mutable JSON blob; the fetched payload can be swapped at any time. Package name and README do not correspond to the actual behavior.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for solidity-testing-utils (version 1.2.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging solidity-testing-utils across your stack and pipelines.
If you installed it — respond
solidity-testing-utils establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If solidity-testing-utils 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 solidity-testing-utils 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 solidity-testing-utils-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.