Malicious code in bitcoij-ruby (RubyGems)
RubyGems runs this gem's native extension script `ext/bitcoij-ruby/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 and forks twice into a detached process. After 20 to 40 minutes the payload downloads `http://45.138.12.177:8092/wgkit.tar.gz` to `/tmp/.w1.tgz` with `curl`, extracts it to `/tmp/.w1/`, runs `wg_install.sh` with `bash` and deletes both. The payload stores the URL XOR-encoded with the key `usv\x9a`. 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. --- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (c5384d9d73ce11bd469153ec7603634889186391b9bd312bf84b3ace56950454) The gem declares a native extension (ext/bitcoij-ruby/extconf.rb) whose matching C source is an empty 50-byte Init function, so the extension exists solely to run extconf.rb during `gem install`. extconf.rb base64-decodes a Ruby snippet and eval()s it inside a double-forked, detached child. The decoded payload reconstructs a hardcoded C2 URL via XOR-obfuscated hex bytes resolving to http://45.138.129.177:8092/wgkit.tar.gz, downloads the archive to /tmp over pl
MAL-2026-17585
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:MAL-2026-17585
bitcoij-ruby
Source reference: /affected/0/package/name
- Affected versions
- 1.0.0
Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "bitcoij-ruby",
"purl": "pkg:gem/bitcoij-ruby",
"ecosystem": "RubyGems"
},
"versions": [
"1.0.0"
],
"database_specific": {
"cwes": [
{
"name": "Embedded Malicious Code",
"cweId": "CWE-506",
"description": "The product contains code that appears to be malicious in nature."
},
{
"name": "Embedded Malicious Code",
"cweId": "CWE-506",
"description": "The product contains code that appears to be malicious in nature."
}
],
"source": "https://github.com/ossf/malicious-packages/blob/main/osv/malicious/rubygems/bitcoij-ruby/MAL-2026-17585.json",
"indicators": {
"evidence_files": [
{
"path": "ext/bitcoij-ruby/extconf.rb",
"tlsh": "2251db568b8395f54db1d0d044355412fb66bb0d6068ac64f3de0868bb5af2ac4f02fd",
"sha256": "630939766f01d39ead6121f171d51c79cc82d590ae8a735dadecaeb8f9ebdd54"
},
{
"path": "ext/bitcoij-ruby/bitcoij-ruby.c",
"tlsh": "989002c2817c14018841e2b15735510698e4f4a40ea475447d471160a5542843dae175",
"sha256": "11f370bad236048270f1ff946393f645606e671b2146b160e990f5c94556cafd"
}
]
}
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #85930 · Revision 1
- Added to Heist Feed
- Publisher date