registry / Remote code execution / datefmt-helper
datefmt-helper
This report shows the evidence for datefmt-helper@1.0.1. 2 of 3 known versions are blocked or flagged. The newest version, 0.0.1-security, is allowed. See all versions.
OpenSSF/OSV Malicious Advisory
imported 4mo ago · by OpenSSF/OSVOpenSSF/OSV advisory MAL-2026-6788 confirms this npm version as malicious.
Advisory
MAL-2026-6788
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in datefmt-helper (npm)
Details
The npm package `datefmt-helper` is a supply-chain dropper disguised as a benign date-formatting utility (its `description` reads "dates formatting utility with locale support"). The package ships no source repository and places its real behaviour in an install script.
A `postinstall` lifecycle hook (`postinstall: node postinstall.js`) executes automatically on `npm install`, before the package is ever imported. The install script uses HTTP / `curl` / `wget` primitives to download a second-stage payload from the hardcoded external IP `115.190.124.243`, then executes it via a Node child process — the classic download-and-execute pattern. Any developer workstation or CI runner that installs the package (directly or transitively) hands arbitrary code execution to the operator of that endpoint. ---
## Source: amazon-inspector (d92b853245953aa75db608f0ae2e5de2321301b94ca6b48f55746a1bd60b6ea4) On `npm install`, the package's postinstall script fetches an unauthenticated payload over plain HTTP from a hardcoded bare IP (115.190.124.243:8761) and executes it. On Unix, `curl`/`wget` output is piped directly to `sh`. On Windows, `certutil.exe -urlcache -split -f` downloads a batch file to C:\Users\Public\run.bat and executes it. The fetched content is unpinned, unverified, and mutable — the operator of the endpoint can serve arbitrary code at any time. The package advertises itself as a lightweight date formatter (`date-fns-lite` branding, impersonating the date-fns ecosystem), but the payload has no relationship to date formatting. The typosquat/impersonation branding combined with an install-time dropper is a supply-chain attack lure.
## Source: ghsa-malware (6c9b82c471edb6b2caeb78c78887556e4c313efc0ba29a88a482b0f93d378807) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Source & flagged code
0 flagged · loading sourceNo flagged code excerpts are attached to this scan.
Findings
1 High
HighOsv Malicious Advisory
Affected versions and remediation
This report applies to datefmt-helper@1.0.1.
The versions list below shows the verdict for each recorded version.
- Avoid installing datefmt-helper@1.0.1. 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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