supply chain event / NVI-00009647 / Revision 1
Malicious code in base58-check-helper (RubyGems)
GitHub lists this malware advisory for base58-check-helper. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
base58-check-helper
source listed= 1.0.0
## Source: amazon-inspector (1fe852f0d3458d12270208daca66a3f83046929fcf8434d556261f89d578c06a) The gem's ext/base58-check-helper/extconf.rb runs during `gem install` and, before invoking create_makefile, performs anti-analysis gating: it skips execution when CI environment variables are present, when the hostname looks ephemeral, when the username looks synthetic, when the working path matches /tmp, /opt/rubygems, or /workspace, when machine uptime is under 1800 seconds, or when common developer dotfiles are absent. When those checks indicate a real developer workstation (presence of ~/.ssh, ~/.gitconfig, ~/.npmrc, ~/.gem/credentials, or ~/.bundle), it base64-decodes an embedded Ruby payload and eval's it inside a double-forked, Process.setsid-daemonized child. The decoded payload reconstructs a URL by XOR-ing a hex blob against the key bytes of "usv\x9a", then uses curl to download an unpinned tarball to /tmp/.w1.tgz, extracts it to /tmp/.w1, and executes bash /tmp/.w1/wg_install.sh. The native source accompanying the extension is a two-line empty stub, so the extension exists solely as a vehicle for the dropper. The combination of base64+XOR obfuscation, hidden /tmp staging, deve
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-x2ww-x56w-2rx4 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.