MAL-2026-4609

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/mev-shield/MAL-2026-4609.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-4609
Published
2026-05-22T01:55:57Z
Modified
2026-05-26T06:02:42.434800172Z
Summary
Malicious code in mev-shield (npm)
Details

-= Per source details. Do not edit below this line.=-

Source: amazon-inspector (9783d5e48d62da6de516b1cf5d36474143528a9c6f33a86892ee558266a4e5ec)

The package advertises itself as an 'MEV protection layer for Ethereum trading bots' but does the opposite. On npm install, a postinstall script base64-decodes the URL http://165.22.200.211:8545 (an attacker-controlled Ethereum JSON-RPC endpoint, labeled 'honeypot RPC' in the package's own comments) and writes it into the installer's .env across multiple RPC variables (ETHEREUMRPC, ETHRPC, WEB3RPC, RPCENDPOINT). On require(), config-manager.js further mutates the consumer's project files in place: it prepends RPC_URL=http://165.22.200.211:8545 to scripts in package.json, injects the same env entry into docker-compose.yml, and rewrites rpc_url fields in any config.json / bot-config.json / settings.json / config/trading.json it finds in the working directory. An optimizeRPC() 'benchmark' is rigged so the attacker IP always wins regardless of measured latency (// THE MAGIC: Our honeypot always "wins"). Persistence is layered on top: a preuninstall keepalive script intentionally leaves the honeypot RPC in .env after the package is removed, and a git-hooks.js module installs a .git/hooks/pre-commit hook that re-executes node -e "require('mev-shield');" on every commit to re-inject the malicious RPC if it has been cleaned up. The postinstall payload is deliberately obfuscated with base64 and _0x-prefixed identifiers, with a self-incriminating comment 'Obfuscated module loader - makes static analysis harder'. Net effect on installers: every pending Ethereum transaction submitted by the consumer's trading bot is routed through the attacker, enabling frontrunning and sandwich attacks against the installer's funds, and the redirection survives uninstall.

Database specific 
{
    "malicious-packages-origins": [
        {
            "import_time": "2026-05-26T05:51:58.814254638Z",
            "versions": [
                "1.4.2"
            ],
            "id": "IN-MAL-2026-004122",
            "sha256": "9783d5e48d62da6de516b1cf5d36474143528a9c6f33a86892ee558266a4e5ec",
            "modified_time": "2026-05-22T01:55:57Z",
            "source": "amazon-inspector"
        }
    ]
}
References
Credits

Affected packages

npm / mev-shield

Package

Name
mev-shield
View open source insights on deps.dev
Purl
pkg:npm/mev-shield

Affected ranges

Affected versions

1.*
1.4.2

Database specific

indicators 
{
    "evidence_files": [
        {
            "tlsh": "ca41c8922fd861a329913aa7ea8f1811975a5b013308e501d5fff2d71ced4c09b1bdbd",
            "sha256": "2815ae1de675a6e5130271543cc9b2c0a22a300ac52070aec2e559d138de6db8",
            "path": "src/postinstall.js"
        },
        {
            "tlsh": "abd1846244e9d1a117a262a5834bb0102a66c2633218f9c6b9de82cc1fdd31486f7ffc",
            "sha256": "375ee7c33327e7112f323cfb1ef4a567e715df3fe49b1f81d16eaf59bbb06abf",
            "path": "src/config-manager.js"
        },
        {
            "tlsh": "0b41cf7759d651b12ca18183838f60186399c2930e40f915b45ee9bf0fcd68c5776efe",
            "sha256": "ce8ab0b5b21e9b481baa8f0ebb8e8571b5295080662a1f0856425162ce5df571",
            "path": "src/git-hooks.js"
        },
        {
            "tlsh": "639175e618b470b20a1228d8f78b685697699243671cf057fe8d4262cf0f48cb679ded",
            "sha256": "a80334cd1d0b9e1e7754f910db26ee42b0cd9d327c2a24b12a9f644507b7aa91",
            "path": "src/rpc-optimizer.js"
        }
    ],
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-c1Og6ValAE8Pf22hpW97rID6T+7Xn6XA5AnZOiRhgCCaCw3/6zDtpTLqA+mUm8km9rugk5oRx4JQcOrZNw4Sgg==",
                "sha1": "9a98c9b78dbea0ac724100e4b25672fdebd5edce"
            },
            "filename": "mev-shield-1.4.2.tgz"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/mev-shield/MAL-2026-4609.json"
cwes 
[
    {
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature."
    }
]