Stealthy Npm Malware Backdoors Popular Ethereum Library

Security researchers at ReversingLabs have discovered a sophisticated malware campaign targeting the npm package repository.

The malicious packages, ethers-provider2 and ethers-providerz, secretly modify a widely used npm package, ethers, to create a backdoor on infected systems. The malware differs from standard npm malware because it uses complex multi-stage attacks to function.

These packages present themselves as real tools by duplicating the SSH2 package, which has received more than 350 million downloads, as noted by the researchers. The malware installs itself by stealing more harmful code, which transforms ethers to embed a concealed reverse shell feature for remote hacker access.

ReversingLabs detected the threat using its Spectra platform. The infection process begins when ethers-provider2 is installed. The downloaded script executes a second-stage malware file which self-deletes following its execution to prevent detection.

The malware checks for the presence of ethers until it detects the package then swaps provider-jsonrpc.js with a fake version that contains hidden malicious code.

The attack doesn’t stop there. The malware creates another file named  loader.js that keeps the infection active after the removal of ethers-provider2.

The attackers establish a reverse shell connection during the third phase of their attack, which enables hackers to execute commands remotely through compromised SSH clients. ReversingLabs described this approach as evidence of advanced threat actor capabilities that requires additional investigation.

The researchers identified ethers-providerz as a potential test version because its coding contained multiple errors but it followed the same pattern as the first malicious package.

The security experts discovered that ethers-provider2 remained accessible on npm at the time of reporting, even though ethers-providerz had been eliminated.

Developers need to check their systems for infection signs while exclusively using trusted npm packages according to security experts.