# MAL-2026-17598: Malicious code in eth-keystore-utils (RubyGems)


- **Type:** Malicious package
- **Package:** `eth-keystore-utils` (RubyGems)
- **Published:** 5 Oct 2026

## What is MAL-2026-17598?

MAL-2026-17598 is a malicious package in eth-keystore-utils, published on 5 Oct 2026. 

### Official description

RubyGems runs this gem's native extension script `ext/req_throttle_mini/extconf.rb` during `gem install`. The script exits without action on CI runners and sandboxes, based on CI environment variables, the hostname, the username and the working directory. It continues if the system uptime is over 30 minutes and the home directory holds `.ssh`, `.gitconfig`, `.npmrc`, `.gem/credentials` or `.bundle`. It then decodes a Base64 Ruby payload, forks twice into a detached process, waits 20 to 40 minutes and opens a reverse shell that connects `/bin/sh` to 45.138.12.177 on TCP port 8090. The shell reconnects every 30 seconds. The Ruby code in `lib/` is a decoy. The RubyGems account `reqthrottle_3474` published this gem and 41 others with the same loader on 2026-10-05.

The gem advertises itself as an Ethereum keystore helper but ships a native extension (ext/req_throttle_mini/extconf.rb) whose sole purpose is to execute a malicious payload during `gem install`. The extconf script base64-decodes an embedded Ruby payload and `eval`s it inside a double-forked, detached child process, then writes an empty Makefile via create_makefile with no C sources present. The decoded payload opens a TCP connection to the hardcoded bare-IP C2 at 45.138.12.177:8090, pipes the socket to `/bin/sh` via IO.popen and IO.copy_stream in both directions, and reconnects on failure in a loop, giving the operator a persistent remote shell on the installer's host. The dropper is gated by anti-analysis checks: it refuses to fire inside CI, ephemeral or sandbox-shaped hostnames, generated usernames, or analysis path prefixes, requires the presence of developer secrets (~/.ssh, ~/.gitconfig, ~/.npmrc, ~/.gem/credentials, ~/.bundle) and sufficient machine uptime, and sleeps 20–40 minutes after detaching before executing to evade install-time scanners. The lib/ module is a thin JSON reader that serves as cover; the native extension ships no real build sources. Package naming targets Ethereum developers likely to hold wallet material and cloud/VCS credentials on their workstations.

The OpenSSF Package Analysis project identified 'eth-keystore-utils' @ 1.0.0 (rubygems) as malicious.

It is considered malicious because:

- The package executes one or more commands associated with malicious behavior.

## What should I do about MAL-2026-17598?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-17598 is a malicious package: eth-keystore-utils (RubyGems). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-17598/ (Markdown: https://insights.sbomify.com/MAL-2026-17598/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-17598

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-17598/
Summaries are generated and may contain mistakes; the official description above is the record.