MAL-2026-17588

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/rubygems/blockchain-sync-utils/MAL-2026-17588.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-17588
Published
2026-10-05T07:30:41Z
Modified
2026-10-06T01:00:16Z
Summary
Malicious code in blockchain-sync-utils (RubyGems)
Details

RubyGems runs this gem's native extension script ext/blockchain-sync-utils/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 (78a8b7d5a56c33e17464f8129001559f02bd245cd299cb8cb07ccc334eb5af65)

The gem's native-extension build script (ext/.../extconf.rb) is a dropper rather than a real build step. The accompanying C source is a no-op stub, so the extension exists only to run install-time code. The script decodes a base64-wrapped Ruby payload and eval()s it inside a detached double-fork (Process.setsid), after gating on anti-analysis checks (CI environment variables, hostname regex, /proc/uptime greater than 1800 seconds, jittered sleep) and on the presence of developer-credential artifacts on the host (~/.ssh, ~/.gitconfig, ~/.npmrc, ~/.gem/credentials, ~/.bundle) so the payload only fires on real developer workstations. The payload's destination URL is stored as a hex blob XORed with a 4-byte key and resolves to http://45.138.122.177:8092/wgkit.tar.gz; the decoded command curls that tarball to /tmp/.w1.tgz, extracts it to /tmp/.w1, and executes bash /tmp/.w1/wg_install.sh. Installing the gem runs attacker-controlled shell code on the installer's machine from a bare-IP endpoint over plain HTTP, with no pinning or integrity check and with explicit sandbox evasion.

Source: ossf-package-analysis (390a0dfcd99333f84570132510c68c56e6d109cbb9a5b1ca1edee83696122c5e)

The OpenSSF Package Analysis project identified 'blockchain-sync-utils' @ 1.0.0 (rubygems) as malicious.

It is considered malicious because:

  • The package executes one or more commands associated with malicious behavior.
Database specific 
{
    "iocs":  {
        "files":  [
            {
                "digests":  {
                    "sha256":  "4c4f9bbbc7fb381c1185255fef4698474ba78f8758aed6618e59933678f9cad0"
                },
                "note":  "Native extension script that RubyGems runs at install time. It gates on the environment and starts the payload.",
                "paths":  [
                    "ext/blockchain-sync-utils/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-2026-021068",
            "import_time":  "2026-10-05T16:22:56.279235652Z",
            "modified_time":  "2026-10-05T15:59:31Z",
            "sha256":  "78a8b7d5a56c33e17464f8129001559f02bd245cd299cb8cb07ccc334eb5af65",
            "source":  "amazon-inspector",
            "versions":  [
                "1.0.0"
            ]
        },
        {
            "import_time":  "2026-10-06T00:50:53.05277237Z",
            "modified_time":  "2026-10-05T07:30:41Z",
            "sha256":  "390a0dfcd99333f84570132510c68c56e6d109cbb9a5b1ca1edee83696122c5e",
            "source":  "ossf-package-analysis",
            "versions":  [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

RubyGems / blockchain-sync-utils

Package

Name
blockchain-sync-utils
Purl
pkg:gem/blockchain-sync-utils

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/blockchain-sync-utils/extconf.rb",
            "sha256":  "4c4f9bbbc7fb381c1185255fef4698474ba78f8758aed6618e59933678f9cad0",
            "tlsh":  "ac51da568b8395f54db1d0d004395412fb66bb0d6068ac64f3de0868bb4af2ac4f02fd"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/rubygems/blockchain-sync-utils/MAL-2026-17588.json"