Malicious code in nft-metadata-resolver (RubyGems)

{
  "id": "40ce30d9648d2fa01dd869d7312b205084e6b6a7bf5c317ceed162c4d5c502c5",
  "url": "https://osv.dev/vulnerability/MAL-2026-17792",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Malicious code in nft-metadata-resolver (RubyGems)",
    "summary": "--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (ee87c382dfd443e81b4cf0e8dc66749f9a129bd4239f984859aaaf760e84c629) The gem ships a native-extension script at ext/nft_metadata_resolver/extconf.rb that RubyGems auto-executes during `gem install`. The script carries a base64-encoded Ruby payload, decodes it with Base64.decode64 and runs it via eval inside a double-forked, detached, delayed child process. The decoded payload opens a TCP connection to the hardcoded bare-IP endpoint 45.138.12.177:8089 and bridges /bin/sh standard I/O to that socket using IO.popen and IO.copy_stream in both directions, giving the remote endpoint an interactive shell on the installer's host. Execution is gated by sandbox-evasion checks that skip CI environments, ephemeral or sandbox hostnames, generated analyst-shaped usernames, analysis working directories, and hosts with short uptimes, firing only when developer-shaped home-directory signals are present. The gem's advertised identity is inconsistent with its contents: the package is published as nft-metadata-resolver, the README describes a 'bitcoin-rpc-lite' library, and the extension declares a makefile target named bitcoin_rpc_lite_native while shipping no native C/C++ source for a real addon build. The extconf.rb's sole purpose is to decode and execute the embedded payload. ## Source: ossf-package-analysis (6025ab6524365bfb72f42951bbd78d214e309ae007eae9150f11c84503c77cdf) The OpenSSF Package Analysis proj",
    "evidence": "osv:MAL-2026-17792",
    "products": [
      {
        "name": {
          "value": "nft-metadata-resolver",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "0.9.1",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "MAL-2026-17792",
      "aliases": [
        "MAL-2026-17792"
      ],
      "affected": [
        {
          "package": {
            "name": "nft-metadata-resolver",
            "purl": "pkg:gem/nft-metadata-resolver",
            "ecosystem": "RubyGems"
          },
          "versions": [
            "0.9.1"
          ],
          "database_specific": {
            "cwes": [
              {
                "name": "Embedded Malicious Code",
                "cweId": "CWE-506",
                "description": "The product contains code that appears to be malicious in nature."
              }
            ],
            "source": "https://github.com/ossf/malicious-packages/blob/main/osv/malicious/rubygems/nft-metadata-resolver/MAL-2026-17792.json",
            "indicators": {
              "evidence_files": [
                {
                  "path": "ext/nft_metadata_resolver/extconf.rb",
                  "tlsh": "9751775acf8359e55aa1c0c045798012faa3ab0a50646875f3ee0868ff59b26c0f12fe",
                  "sha256": "10218e975f54a4f11fe3954e1b584a5f05054003bf5773c3c2b8cceaa74ba763"
                }
              ]
            }
          }
        }
      ],
      "modified": "2026-10-13T23:30:05.010775073Z",
      "provider": "osv",
      "references": [
        "https://rubygems.org/gems/nft-metadata-resolver/versions/0.9.1"
      ],
      "provider_metadata": {
        "malicious-packages-origins": [
          {
            "id": "IN-MAL-2026-021366",
            "sha256": "ee87c382dfd443e81b4cf0e8dc66749f9a129bd4239f984859aaaf760e84c629",
            "source": "amazon-inspector",
            "versions": [
              "0.9.1"
            ],
            "import_time": "2026-10-11T14:17:59.680862705Z",
            "modified_time": "2026-10-11T13:48:27Z"
          },
          {
            "sha256": "6025ab6524365bfb72f42951bbd78d214e309ae007eae9150f11c84503c77cdf",
            "source": "ossf-package-analysis",
            "versions": [
              "0.9.1"
            ],
            "import_time": "2026-10-13T23:14:39.710433545Z",
            "modified_time": "2026-10-11T07:25:28Z"
          }
        ]
      }
    },
    "related_cves": [],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 313739,
  "published_at": "2026-10-11T07:25:28+00:00"
}