Four npm packages found opening shells and collecting info on Linux, Windows systems

On Thursday, four JavaScript packages have been removed from the npm portal because they have been found containing malicious code.

NPM staff removed four JavaScript packages from the npm portal because were containing malicious code. Npm is the largest package repository for any programming language.

The four packages, which had a total of one thousand of downloads, are:

“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 npm security team said.

“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,”

The researcher AX Sharma, who analyzed the packages, revealed that plutov-slack-client, nodetest1010, and nodetest199 share identical code.

Experts warn that systems running applications that imported one of these packages should be potentially compromised because the three JavaScript libraries opened web shells on the computers running them.

A web shell is a code, often written in typical web development programming languages (e.g., ASP, PHP, JSP), that attackers implant on web servers to gain remote access and code execution.

The npmpubman, unlike the other packages, was found collecting user data from the environment variables and uploads the gathered info to a remote host.

The malicious code could work on both Windows and *nix operating systems, including major distros, including Linux, FreeBSD, OpenBSD.

One of the packages was uploaded on the npm portal in May, while the remaining ones were uploaded in September 2018.

“It is possible that all four packages were authored by the same attacker(s) despite conflicting data provided in the package.json manifests.” reported Bleeping Computer.

“In a real-world scenario, npmpubman could be used as a part of an attacker’s reconnaissance efforts to collect information about a system, whereas the other packages establish a direct connection between the attacker’s and the victim’s computers.”

In August, the npm security team has removed the JavaScript library “fallguys” from the npm portal because it was containing a malicious code used to steal sensitive files from an infected users’ browser and Discord application.

Pierluigi Paganini

(SecurityAffairs – hacking, malware)