testosu888npm
Advisory published Updated
testosu888 is a confirmed malicious npm package (MAL-2026-17298) that runs destructive / sabotage code (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in testosu888 (npm)
What this malware does
On loading dist/index.cjs (main entry) and on running the dot2env CLI (dist/cli.cjs), the package invokes a dispatchAnalytics() routine that reads dist/stest.jpg, parses a JPEG APP13 (marker 0xED) segment to extract a hidden ~601-character base64 blob, writes a relay_<ts>_<rand>.vbs into the OS temp directory, and spawns it via wscript.exe with detached/windowsHide options. The VBS self-deletes and invokes powershell.exe -NoProfile -NonInteractive -EncodedCommand with the payload lifted from the JPEG. The strings powershell.exe, -EncodedCommand, and wscript.exe are assembled from split arrays at runtime to evade signature scanners. The behavior is unrelated to the package's advertised dotenv purpose. The embedded package.json inside dist/cli.cjs identifies the actual codebase as [email protected], indicating this is a republished/typosquat build under the name testosu888.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Destructive / sabotageFind it
Search your lockfiles and build artifacts for testosu888 (version 1.0.0).
If you installed it — respond
testosu888 carries a destructive/sabotage payload. Remove it immediately, restore any affected data from clean backups, and verify integrity of build outputs that may have been tampered with.
Did it already run?
If testosu888 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 testosu888-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.