Malicious code in evilpostinstall (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (846e500b06f58769a2cb833be8e726ab1db04b327f4c614da6642eb46ae7dfe5) The package's postinstall lifecycle hook pipes the output of `env` through `nc` to a host reconstructed at install time from the package version string via `cut -b 2-4` and `cut -b 5-`. For version 4127000.0.1 the destination decodes to 127.0.0.1:888; the sibling artifact evilpostinstall-192.168.1.100.tgz uses the same slicing scheme to target 192.168.1.100. On `npm install`, the full installer environment - including any CI secrets, tokens, and API keys present in environment variables - is transmitted to the reconstructed host over TCP port 888. package.json also declares a self-referencing dependency `evilpostinstall: ^4192168.1.100`, whose version field encodes a second destination IP under the same scheme, causing npm to resolve and install an additional package instance whose own postinstall repeats the exfiltration against that address. The destination is deliberately hidden from static scanners by being reconstructed from the version field rather than written as an IP literal, and no source files are shipped - the manifest itself is the payload. ## Source: ossf-package-analysis (c4f0004a363677a7dc0429c4cf4bacafcd3bbdab0c95e1e7851d44b543d7e486) The OpenSSF Package Analysis project identified 'evilpostinstall' @ 4127000.0.1 (npm) as malicious. It is considered malicious because: - The package executes one or more commands associated with malicious behavior.
Malicious code in evilpostinstall (npm)
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (846e500b06f58769a2cb833be8e726ab1db04b327f4c614da6642eb46ae7dfe5) The package's postinstall lifecycle hook pipes the output of `env` through `nc` to a host reconstructed at install time from the package version string via `cut -b 2-4` and `cut -b 5-`. For version 4127000.0.1 the destination decodes to 127.0.0.1:888; the sibling artifact evilpostinstall-192.168.1.100.tgz uses the same slicing scheme to target 192.168.1.100. On `npm install`, the full installer environment - including any CI secrets, tokens, and API keys present in environment variables - is transmitted to the reconstructed host over TCP port 888. package.json also declares a self-referencing dependency `evilpostinstall: ^4192168.1.100`, whose version field encodes a second destination IP under the same scheme, causing npm to resolve and install an additional package instance whose own postinstall repeats the exfiltration against that address. The destination is deliberately hidden from static scanners by being reconstructed from the version field rather than written as an IP literal, and no source files are shipped - the manifest itself is the payload. ## Source: ossf-package-analysis (c4f0004a363677a7dc0429c4cf4bacafcd3bbdab0c95e1e7851d44b543d7e486) The OpenSSF Package Analysis project identified 'evilpostinstall' @ 4127000.0.1 (npm) as malicious. It is considered malicious because: - The package executes one or more commands associated with malicious behavior.
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-15625
- Osv Schema Version
- 1.7.4
- Aliases
- []
- Ecosystems
- ["npm"]
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a984534acd9273b496aaa16
Added to database: 09/02/2026, 15:48:04 UTC
Last updated: 09/02/2026, 15:48:04 UTC
Views: 1
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.