simple-date-formatter-util-7npm
Advisory published Updated
simple-date-formatter-util-7 is a confirmed malicious npm package (MAL-2026-11998) that opens a backdoor for remote access (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in simple-date-formatter-util-7 (npm)
What this malware does
Package advertises itself as a date formatter utility but ships a malicious postinstall payload. package.json declares a postinstall lifecycle script that spawns an interactive bash reverse shell over /dev/tcp to 124.221.154.135:4444, giving a remote party command execution on the installer's host immediately after npm install. A bundled postinstall.js additionally enumerates the installer's ~/.ssh directory and POSTs the listing along with username and platform metadata to the same host at 124.221.154.135 over HTTPS. Advertised purpose (date formatting) does not require network access, shell execution, or SSH directory reads.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for simple-date-formatter-util-7 (version 1.0.0).
If you installed it — respond
simple-date-formatter-util-7 establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If simple-date-formatter-util-7 was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks simple-date-formatter-util-7-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.