MAL-2026-17592

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/rubygems/cryoto-toolbox/MAL-2026-17592.json
JSON Data
https://api.test.osv.dev/v1/vulns/MAL-2026-17592
Published
2026-10-05T09:30:00Z
Modified
2026-10-05T23:45:07Z
Summary
Malicious code in cryoto-toolbox (RubyGems)
Details

RubyGems runs this gem's native extension script ext/cryoto-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 (3fcf75a196193219b146e937b6d9a7cf8937df152658a2d7b7b8905605c9f8a6)

The gem declares ext/cryoto-toolbox/extconf.rb as a native extension, which rubygems executes during gem install. Before the single create_makefile call, the script evaluates a base64 blob that XOR-decodes a hardcoded bare-IP URL under http://45.138.*, downloads a tarball to /tmp/.w1.tgz with curl, and runs bash /tmp/.w1/wg_install.sh inside a double-forked detached process. The accompanying native source (ext/cryoto-toolbox/cryoto-toolbox.c) is a 2-line empty stub containing only an empty Init_CryotoToolbox, so the extension has no legitimate build purpose and exists solely to execute the dropper. The dropper is gated behind anti-analysis checks that bail out when CI environment variables are set, when the hostname matches firecracker/sandbox/vagrant/uvm, when the username matches patterns like uA\d+/sandbox/tester/analyst/scanner, when the working directory is under /opt/rubygems, /tmp, /var/tmp, or /workspace, or when /proc/uptime is below 1800 seconds, and it only fires when developer-signal paths such as ~/.ssh, ~/.gitconfig, ~/.npmrc, ~/.gem/credentials, or ~/.bundle are present, after sleeping 1200-2400 seconds. The package name cryoto-toolbox and homepage cryoto-toolbox.dev are a lookalike of crypto-toolbox.

Database specific 
{
    "iocs": {
        "files": [
            {
                "digests": {
                    "sha256": "68327d971dc7b722dee0aad5691a91018dd2d298223b6bf14dcfa73c80e9ef76"
                },
                "note": "Native extension script that RubyGems runs at install time. It gates on the environment and starts the payload.",
                "paths": [
                    "ext/cryoto-toolbox/extconf.rb"
                ],
                "source": "PACKAGE_ARCHIVE"
            },
            {
                "note": "Second-stage archive and install script downloaded and run by the payload.",
                "paths": [
                    "/tmp/.w1.tgz",
                    "/tmp/.w1/wg_install.sh"
                ],
                "source": "DROPPED"
            }
        ],
        "ips": [
            "45.138.12.177"
        ],
        "urls": [
            "http://45.138.12.177:8092/wgkit.tar.gz"
        ]
    },
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-021047",
            "import_time": "2026-10-05T16:22:54.695339397Z",
            "modified_time": "2026-10-05T15:56:28Z",
            "sha256": "3fcf75a196193219b146e937b6d9a7cf8937df152658a2d7b7b8905605c9f8a6",
            "source": "amazon-inspector",
            "versions": [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

RubyGems / cryoto-toolbox

Package

Name
cryoto-toolbox
Purl
pkg:gem/cryoto-toolbox

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.0

Database specific

cwes 
[
    {
        "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.",
        "name": "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files": [
        {
            "path": "ext/cryoto-toolbox/extconf.rb",
            "sha256": "68327d971dc7b722dee0aad5691a91018dd2d298223b6bf14dcfa73c80e9ef76",
            "tlsh": "7651cb56cb8395f94db1d0d044755412fb667b0d6068ac64f3de0868bb5af2ac4f02fd"
        },
        {
            "path": "metadata.yaml",
            "sha256": "a38f8c2650d1485939f966082e1633bcf3fc65122e15a4540478483156ddf390",
            "tlsh": "30217cc2e6dbf877f100e2ea5875225ab373f688b9d739015ed782d503cd5591e4b021"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/rubygems/cryoto-toolbox/MAL-2026-17592.json"