{"items":[{"id":"NVI-00009647","kind":"supply_chain_event","title":"Malicious code in base58-check-helper (RubyGems)","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-x2ww-x56w-2rx4"],"plain_summary":"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.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-1dab3d1f82bd234b0dc3fa904dead302"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-1dab3d1f82bd234b0dc3fa904dead302","url":"https://github.com/advisories/GHSA-x2ww-x56w-2rx4","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-x2ww-x56w-2rx4","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T22:07:22.853Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-1dab3d1f82bd234b0dc3fa904dead302"],"technology":"base58-check-helper","known_exclusions":[],"conditions_summary":"## Source: amazon-inspector (1fe852f0d3458d12270208daca66a3f83046929fcf8434d556261f89d578c06a)\nThe 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","public_affected_ranges":["= 1.0.0"]}],"null_published_at":"2026-10-31T22:13:39.927Z","source_updated_at":"2026-10-06T03:32:26.000Z","source_disclosed_at":"2026-10-05T18:34:13.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-10-31T22:07:22.853Z"}],"next_cursor":null,"snapshot_revision":"42594"}