{"answers":{"affected":"1 open source package ship an affected version, including bigint.fs.","exploited":"There is no known exploitation of MAL-2026-3750 in the wild and no public exploit code.","fix":"Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.","what":"MAL-2026-3750 is a malicious package in bigint.fs, published on 14 May 2026."},"fix_prompt":"MAL-2026-3750 is a malicious package: bigint.fs (npm). Every version was published to cause harm.\n\nTask:\n1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.\n2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.\n3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.\n4. If the package is not used anywhere, say so and change nothing.\n\nReference: https://insights.sbomify.com/MAL-2026-3750/ (Markdown: https://insights.sbomify.com/MAL-2026-3750/index.md)","id":"MAL-2026-3750","markdown":"https://insights.sbomify.com/MAL-2026-3750/index.md","name":"MAL-2026-3750","record":{"aliases":["GHSA-pcvf-7w5m-j39j"],"analysis":null,"analysis_generated_by":null,"assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"On require()/import, index.js runs an IIFE that POSTs a getAccountInfo RPC call to https://api.devnet.solana.com for Solana account 4WF8QCFEnVD7BLs3QAVe2SjxRZ4n3EboCsdhj363VAqZ, base64-decodes the returned account data, reads a length prefix at offset 32, extracts the payload bytes at offset 36, and passes the resulting UTF-8 source to `new Function('require','module','exports', src)` — executing arbitrary JavaScript with the full privileges of the importing Node.js process. The payload is mutable (the attacker can rewrite the on-chain account data at any time), unpinned, not hash- or signature-verified, and delivered from infrastructure the attacker controls. The use of a public blockchain RPC endpoint as a C2 channel is designed to evade simple domain/IP blocking while remaining fully attacker-rewritable. The package name masquerades as a BigInt/filesystem utility; there is no legitimate reason for such a library to fetch and eval remote code on load.\n\nAny 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.","ecosystems":["npm"],"exploits":{"exploitdb":null,"first_seen":null,"github_poc":null,"max_poc_stars":null,"metasploit":null,"nuclei":null,"refs":[],"tier":null},"has_fix":false,"headline":"Malicious code in bigint.fs (npm)","id":"MAL-2026-3750","indexable":true,"kev":null,"kind":"malicious","links":{"ecosystem":"npm","product":null,"products":[],"type":null,"year":"2026"},"n_packages":1,"n_references":null,"packages":[{"ecosystem":"npm","fixed":[],"introduced":[],"last_affected":[],"package":"bigint.fs","purl":"pkg:npm/bigint.fs","source":"MAL-2026-3750"}],"products":null,"published":"2026-05-14","related":[],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"OpenSSF Malicious Packages","prefix":"MAL"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":null,"updated":null,"vendors":null},"summary":null,"url":"https://insights.sbomify.com/MAL-2026-3750/"}