mal-2026-4420
Vulnerability from ossf_malicious_packages
-= Per source details. Do not edit below this line.=-
Source: amazon-inspector (f93cf8dde7e6a1252424fc82f38e8502a37d9e427d92d412fd8944c91b8ee5a4)
On npm install, scripts/postinstall.js downloads a per-OS payload from https://oob.moika.tech/payload/{linux|mac|win}, writes it to /tmp/._polka-ui_init.sh (or.bat), chmods 0755, and spawns it via /bin/sh or cmd.exe with no integrity verification. The same script enumerates process.env for credential-shaped keys (npm_token, github_token, aws_access_key_id, aws_secret_access_key, aws_session_token, artifactory_token, nexus_token, node_auth_token, npm_config__auth), reads the first 15 lines of ~/.npmrc, /etc/npmrc,./.npmrc, and../.npmrc, and POSTs a JSON report containing hostname, username, cwd, PATH, the harvested env values, npmrc contents, and npm registry config to https://oob.moika.tech/report with an X-Secret header. The package self-describes as a dependency-confusion PoC under the @polka-ui scope; regardless of stated intent, any installer who resolves this from public npm receives full install-time RCE and credential exfiltration.
Source: ghsa-malware (1563c5a344109d7c86e90afa23b70aebf0ad1c876f648d0bdba11975c064b3f4)
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
{
"affected": [
{
"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": {
"domains": [
"oob.moika.tech"
],
"evidence_files": [
{
"path": "scripts/postinstall.js",
"sha256": "26bf62d9dabf1e50ebad953065036714e492824a321cb0f3c27434f37d144fd7",
"tlsh": "5fc1eadb22fb553403d6a2e6e51f6412e227b1033905e9e0f95c91145f8a6bcd2b3eec"
}
],
"package_integrity": [
{
"filename": "loader-9.9.10.tgz",
"hashes": {
"sha1": "c59a95881d6ea38188601ac294eb2ded3bef4737",
"sha512_sri": "sha512-cva0rVuPbEg/KgOQWVE/Me+W6zAFTJ05KTnR8l7TLPFxgEqDd8AabIvvjbXNdPmCnmRh53iJPxaD1ZBb2189Tg=="
}
}
]
}
},
"package": {
"ecosystem": "npm",
"name": "@polka-ui/loader"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "SEMVER"
}
],
"versions": [
"9.9.10"
]
}
],
"aliases": [
"GHSA-j263-hx4f-ph92"
],
"credits": [
{
"contact": [
"actran@amazon.com"
],
"name": "Amazon Inspector",
"type": "FINDER"
}
],
"database_specific": {
"malicious-packages-origins": [
{
"id": "IN-MAL-2026-004712",
"import_time": "2026-05-26T05:53:08.302448288Z",
"modified_time": "2026-05-25T15:39:02Z",
"sha256": "599a7dd2ffe3f950a7dcf18279f01e9e4e6e457741b73fff5ace7a283b9c9539",
"source": "amazon-inspector",
"versions": [
"9.9.10"
]
},
{
"id": "IN-MAL-2026-004711",
"import_time": "2026-05-26T05:53:08.19150824Z",
"modified_time": "2026-05-25T15:39:02Z",
"sha256": "f93cf8dde7e6a1252424fc82f38e8502a37d9e427d92d412fd8944c91b8ee5a4",
"source": "amazon-inspector",
"versions": [
"9.9.10"
]
},
{
"id": "GHSA-j263-hx4f-ph92",
"import_time": "2026-05-28T15:25:19.330336332Z",
"modified_time": "2026-05-28T13:39:49Z",
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "SEMVER"
}
],
"sha256": "1563c5a344109d7c86e90afa23b70aebf0ad1c876f648d0bdba11975c064b3f4",
"source": "ghsa-malware"
}
]
},
"details": "\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (f93cf8dde7e6a1252424fc82f38e8502a37d9e427d92d412fd8944c91b8ee5a4)\nOn `npm install`, scripts/postinstall.js downloads a per-OS payload from https://oob.moika.tech/payload/{linux|mac|win}, writes it to /tmp/._polka-ui_init.sh (or.bat), chmods 0755, and spawns it via /bin/sh or cmd.exe with no integrity verification. The same script enumerates process.env for credential-shaped keys (npm_token, github_token, aws_access_key_id, aws_secret_access_key, aws_session_token, artifactory_token, nexus_token, node_auth_token, npm_config__auth), reads the first 15 lines of ~/.npmrc, /etc/npmrc,./.npmrc, and../.npmrc, and POSTs a JSON report containing hostname, username, cwd, PATH, the harvested env values, npmrc contents, and npm registry config to https://oob.moika.tech/report with an X-Secret header. The package self-describes as a dependency-confusion PoC under the @polka-ui scope; regardless of stated intent, any installer who resolves this from public npm receives full install-time RCE and credential exfiltration.\n\n## Source: ghsa-malware (1563c5a344109d7c86e90afa23b70aebf0ad1c876f648d0bdba11975c064b3f4)\nAny computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.\n",
"id": "MAL-2026-4420",
"modified": "2026-05-28T15:26:36Z",
"published": "2026-05-25T15:39:02Z",
"references": [
{
"type": "PACKAGE",
"url": "https://www.npmjs.com/package/@polka-ui/loader/v/9.9.10"
},
{
"type": "ADVISORY",
"url": "https://github.com/advisories/GHSA-j263-hx4f-ph92"
}
],
"schema_version": "1.7.4",
"summary": "Malicious code in @polka-ui/loader (npm)"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.