Malicious code in @marketfront/mychatspreloader (npm)
The @marketfront/mychatspreloader package is part of a 25-package malicious campaign batch-published to the @marketfront npm scope by npm user 'marketfront' ([email protected]) within a roughly 3-minute window on 2026-07-01. All packages in the campaign were published at version 7.0.0 and use e-commerce/marketing frontend component names as cover.
The package declares a postinstall hook (node scripts/postinstall.js) that executes heavily obfuscated (obfuscator.io-style) code automatically at npm install time. Static analysis of the decoded payload revealed a credential harvester that dynamically requires fs, os, http, https, zlib, path and dns, then reads approximately 20 sensitive credential files including ~/.ssh, ~/.aws/credentials, ~/.kube/config, ~/.docker/config.json, ~/.npmrc, ~/.netrc, ~/.pgpass, ~/.git-credentials, ~/.env and ~/.bash_history. Collected data is exfiltrated via a gzip-compressed HTTPS POST with a custom X-Secret header to the path /api/v1/events, alongside a DNS resolver beacon. The command-and-control host is concealed behind an additional RC4+XOR encryption layer around an embedded configuration blob and was not statically resolved.
The decoded behavioral payload (module requires, credential-file target list, exfiltration headers and endpoint) is byte-for-byte identical across sampled packages in the campaign. The campaign shares tooling and infrastructure patterns (obfuscated postinstall credential harvester, X-Secret header, /api/v1/events exfiltration path, RC4-concealed C2) with the earlier @emcd-vue campaign, indicating the same actor rotating scopes and disposable maintainer emails.
Source: amazon-inspector
The package ships a heavily obfuscated postinstall.js (obfuscator.io-style: rotated string array of length 213, RC4/base64 decoders, numeric-charcode arrays decoded at runtime) that runs automatically on npm install. On execution it enumerates the entire process.env, collects OS identifiers via os.hostname(), os.userInfo(), os.networkInterfaces(), and os.cpus(), and reads Windows-specific environment variables (USERDOMAIN, COMPUTERNAME, APPDATA, LOCALAPPDATA, TEMP, PROGRAMDATA). It then reads files under the user's APPDATA/LOCALAPPDATA/TEMP/PROGRAMDATA directories — where browser profiles, wallet stores, and app credential files reside on Windows — and includes their contents in the outbound payload. The collected data is exfiltrated over two channels: an HTTPS POST and DNS-subdomain queries via dns.Resolver (a classic DNS-tunnel exfil channel used to bypass HTTP egress filtering). The package has no library functionality: main points to dist/index.js which requires ../src/index.js, and no src/ directory is shipped in the tarball — the only effect of installing the package is the malicious postinstall. The @marketfront scope and README (referencing marketfront.io / npm.marketfront.io / jira.marketfront.io as an internal registry) present a dependency-confusion cover story targeting an organization that expects a private @marketfront/* package from an internal registry.
