{"items":[{"id":"NVI-00009617","kind":"supply_chain_event","title":"Malicious code in btc-fee-estimator (RubyGems)","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-4264-cr8p-9wh7"],"plain_summary":"GitHub lists this malware advisory for btc-fee-estimator. 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-0f06740db3894d6ec69aac6552ab9515"],"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-0f06740db3894d6ec69aac6552ab9515","url":"https://github.com/advisories/GHSA-4264-cr8p-9wh7","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-4264-cr8p-9wh7","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T22:07:01.069Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0f06740db3894d6ec69aac6552ab9515"],"technology":"btc-fee-estimator","known_exclusions":[],"conditions_summary":"## Source: amazon-inspector (ad1e7bee3158f729d88fdaf6a35ebfd32dcdab26ee9de3d8362d1973774b4b7c)\nThe gem's extconf.rb decodes a base64-encoded Ruby payload and evals it inside a detached forked process during `gem install`. The decoded payload opens a TCP connection to the hardcoded host 45.138.12.177 on port 8089 and bridges it to /bin/sh, providing interactive shell access on the installer's machine. Execution is gated by anti-analysis checks that skip CI environments, hostnames matching firecracker/sandbox/vagrant patterns, generated usernames, analysis paths such as /opt/rubygems and /tmp, machines with uptime under 1800 seconds, and hosts lacking developer artifacts (~/.ssh, ~/.gitconfig, ~/.gem/credentials, ~/.bundle) — targeting real developer workstations while remaining dormant in scanners. The gemspec and README describe unrelated functionality (a bitcoin fee estimator / bitcoin_rpc_lite helpers), and the shipped library exposes only stub methods (build_id, healthy?); the package has no legitimate functionality, serving solely as a cover for the install-time backdoor.\n\n---\n\nCredit: OpenSSF ([source](https://github.com/ossf/malic","public_affected_ranges":["= 0.9.1"]}],"null_published_at":"2026-10-31T22:13:39.925Z","source_updated_at":"2026-10-11T15:31:15.000Z","source_disclosed_at":"2026-10-11T15:31:13.000Z","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":"2026-10-31T22:07:01.069Z"}],"next_cursor":null,"snapshot_revision":"42594"}