Malicious code in @appupdate/cdn-sync (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (445a7b613694730e29915d732e3df0700d145622b279b62b0a141c76211e6f14) Package @appupdate/cdn-sync ships as a thin koffi wrapper around prebuilt Go cgo native libraries (~12MB linux.so, ~11MB darwin.dylib for x64/arm64). The JS surface exports `ProbeStart(knock)` / `ProbeStop` / `ProbeRunning` / `ProbeLastError`, where `ProbeStart` requires a caller-supplied passphrase that must match a value compiled into the native binary (per the source comment: 'knock must match the BuiltinKnock compiled into native'). The README explicitly states that endpoints and authentication are encapsulated inside the native binary so installers cannot inspect them. Strings inside the shipped binaries reference Tencent Cloud Object Storage endpoints (`cos.myqcloud.com`, `tencentcos.cn`, `https://%s.cos.%s.myqcloud.com`), indicating the worker is linked against the Tencent COS SDK with destination bucket and credentials embedded in opaque bytes. The advertised purpose (CDN static-asset sync) does not match the only exported symbol family (`Probe*`), and publisher metadata is an unfilled placeholder (`github.com/your-org/appupdate.git`, license UNLICENSED, generic `@appupdate` scope) providing no verifiable identity. The combination of a passphrase-gated activation path, deliberately hidden destination and credentials inside a shipped binary, doc-mismatched cover story, and placeholder publisher metadata is the structural shape of a covert uploader / backdoor: once an installer or downstream caller invokes `ProbeStart` with the right knock, attacker-controlled code executes on the installer's machine against a Tencent COS bucket the installer cannot see or audit.
AI Analysis
Technical Summary
The @appupdate/cdn-sync npm package (version 1.0.2) includes a thin JavaScript wrapper around large prebuilt native Go cgo libraries containing embedded Tencent Cloud Object Storage endpoints and credentials. The package exports functions such as ProbeStart that require a passphrase matching a compiled-in secret to activate. This activation enables covert uploading of data to attacker-controlled Tencent COS buckets, which are opaque and cannot be audited by the installer. The package metadata is incomplete and generic, and the README's stated purpose (CDN static-asset sync) does not align with the actual exported functionality, indicating the package is a malicious backdoor rather than a legitimate utility.
Potential Impact
If installed and activated by supplying the correct passphrase, the package enables execution of attacker-controlled code on the host machine, allowing unauthorized data exfiltration to Tencent Cloud Object Storage. This compromises confidentiality and potentially integrity of the affected system. The malicious functionality is hidden inside native binaries, making detection and auditing difficult for users.
Mitigation Recommendations
No official patch or remediation is currently available. Users should avoid installing or using version 1.0.2 of @appupdate/cdn-sync. Since this is a malicious package, the best mitigation is to remove it from any environments where it is present and audit for any signs of compromise. Monitor package sources carefully and prefer verified packages with known publisher identities.
Malicious code in @appupdate/cdn-sync (npm)
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (445a7b613694730e29915d732e3df0700d145622b279b62b0a141c76211e6f14) Package @appupdate/cdn-sync ships as a thin koffi wrapper around prebuilt Go cgo native libraries (~12MB linux.so, ~11MB darwin.dylib for x64/arm64). The JS surface exports `ProbeStart(knock)` / `ProbeStop` / `ProbeRunning` / `ProbeLastError`, where `ProbeStart` requires a caller-supplied passphrase that must match a value compiled into the native binary (per the source comment: 'knock must match the BuiltinKnock compiled into native'). The README explicitly states that endpoints and authentication are encapsulated inside the native binary so installers cannot inspect them. Strings inside the shipped binaries reference Tencent Cloud Object Storage endpoints (`cos.myqcloud.com`, `tencentcos.cn`, `https://%s.cos.%s.myqcloud.com`), indicating the worker is linked against the Tencent COS SDK with destination bucket and credentials embedded in opaque bytes. The advertised purpose (CDN static-asset sync) does not match the only exported symbol family (`Probe*`), and publisher metadata is an unfilled placeholder (`github.com/your-org/appupdate.git`, license UNLICENSED, generic `@appupdate` scope) providing no verifiable identity. The combination of a passphrase-gated activation path, deliberately hidden destination and credentials inside a shipped binary, doc-mismatched cover story, and placeholder publisher metadata is the structural shape of a covert uploader / backdoor: once an installer or downstream caller invokes `ProbeStart` with the right knock, attacker-controlled code executes on the installer's machine against a Tencent COS bucket the installer cannot see or audit.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The @appupdate/cdn-sync npm package (version 1.0.2) includes a thin JavaScript wrapper around large prebuilt native Go cgo libraries containing embedded Tencent Cloud Object Storage endpoints and credentials. The package exports functions such as ProbeStart that require a passphrase matching a compiled-in secret to activate. This activation enables covert uploading of data to attacker-controlled Tencent COS buckets, which are opaque and cannot be audited by the installer. The package metadata is incomplete and generic, and the README's stated purpose (CDN static-asset sync) does not align with the actual exported functionality, indicating the package is a malicious backdoor rather than a legitimate utility.
Potential Impact
If installed and activated by supplying the correct passphrase, the package enables execution of attacker-controlled code on the host machine, allowing unauthorized data exfiltration to Tencent Cloud Object Storage. This compromises confidentiality and potentially integrity of the affected system. The malicious functionality is hidden inside native binaries, making detection and auditing difficult for users.
Mitigation Recommendations
No official patch or remediation is currently available. Users should avoid installing or using version 1.0.2 of @appupdate/cdn-sync. Since this is a malicious package, the best mitigation is to remove it from any environments where it is present and audit for any signs of compromise. Monitor package sources carefully and prefer verified packages with known publisher identities.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-6531
- Osv Schema Version
- 1.7.4
- Aliases
- []
- Ecosystems
- ["npm"]
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a3ef79227e9c79719ff7b19
Added to database: 06/26/2026, 22:05:06 UTC
Last enriched: 07/10/2026, 12:07:49 UTC
Last updated: 07/29/2026, 07:25:02 UTC
Views: 45
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