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Malicious code in crypti-toolbox (RubyGems)

Type: advisorySource: OSV1 source record

RubyGems runs this gem's native extension script `ext/crypti-toolbox/extconf.rb` during `gem install`. The script exits without action on CI runners and sandboxes, based on CI environment variables, the hostname, the username and the working directory. It continues if the system uptime is over 30 minutes and the home directory holds `.ssh`, `.gitconfig`, `.npmrc`, `.gem/credentials` or `.bundle`. It then decodes a Base64 Ruby payload and forks twice into a detached process. After 20 to 40 minutes the payload downloads `http://45.138.12.177:8092/wgkit.tar.gz` to `/tmp/.w1.tgz` with `curl`, extracts it to `/tmp/.w1/`, runs `wg_install.sh` with `bash` and deletes both. The payload stores the URL XOR-encoded with the key `usv\x9a`. The Ruby code in `lib/` is a decoy. The RubyGems account `reqthrottle_3474` published this gem and 41 others with the same loader on 2026-10-05. --- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (5ec4d5d5915335d90b2f18b45b050936fa5d2db9d176d7d081bd8c292c7c6795) On `gem install`, the native extension script ext/crypti-toolbox/extconf.rb runs an environment-fingerprinting routine that bails out on CI runners, ephemeral/sandbox hostnames, generated or analysis-shaped usernames, analysis path prefixes (/opt/rubygems, /tmp, /workspace), low machine uptime, and hosts lacking developer artifacts (~/.ssh, ~/.gitconfig, ~/.gem/credentials). On hosts that pass those checks, the script base64-decodes a Ruby snippet and passes

Announced Source revision 1
Original source ↗

MAL-2026-17593

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:MAL-2026-17593

crypti-toolbox

Source reference: /affected/0/package/name

Affected versions
1.0.0

Source reference: /affected/0/versions

Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "crypti-toolbox",
      "purl": "pkg:gem/crypti-toolbox",
      "ecosystem": "RubyGems"
    },
    "versions": [
      "1.0.0"
    ],
    "database_specific": {
      "cwes": [
        {
          "name": "Embedded Malicious Code",
          "cweId": "CWE-506",
          "description": "The product contains code that appears to be malicious in nature."
        },
        {
          "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/crypti-toolbox/MAL-2026-17593.json",
      "indicators": {
        "evidence_files": [
          {
            "path": "ext/crypti-toolbox/extconf.rb",
            "tlsh": "e351ba568b8395f54db1d0d044359412fb66bb0d6068ad64f3de0868ab5af2ac4f02fd",
            "sha256": "28f8c3f8d138d2bfd8c6a23ec1124210d1e14113f452330332e06a0d4727a8a4"
          }
        ]
      }
    }
  }
]

Publisher severity

No explicit severity was provided.

Event
#85976 · Revision 1
Added to Heist Feed
Publisher date
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