EtherRAT — Node.js Backdoor with Ethereum Blockchain C2 (EtherHiding) Linked to DPRK Contagious Interview — Threadlinqs Intelligence
As of 2026-05-30, EtherRAT — Node.js Backdoor with Ethereum Blockchain C2 (EtherHiding) Linked to DPRK Contagious Interview is a critical-severity malware threat attributed to DPRK APT (North Korea), tracked by Threadlinqs Intelligence with 9 detection rules (Splunk SPL, Microsoft KQL, Sigma) and 36 indicators of compromise.
Threat ID: TL-2026-0293 · Severity: CRITICAL · CVSS: 9.1 · Status: ACTIVE · Category: MALWARE
Attribution: DPRK APT · North Korea · FINANCIAL
EtherRAT is a multi-platform Node.js backdoor linked to North Korean APT operations (Contagious Interview / Jade Sleet). It uses Ethereum smart contracts to store and rotate C2 addresses (EtherHiding
EtherRAT is a sophisticated Node.js-based remote access trojan (RAT) that represents a significant evolution in North Korean cyber operations, combining blockchain-based command and control infrastructure with multi-platform targeting capabilities.
## Architecture & Capabilities
EtherRAT operates as a modular Node.js implant with the following core capabilities: arbitrary command execution via AsyncFunction constructor providing full Node.js context (require, process, Buffer), comprehensive system fingerprinting through the SYS_INFO module, cryptocurrency wallet and cloud credential theft, self-reobfuscation by POSTing its own source code to C2 for server-side transformation, and an interactive JavaScript shell with complete module access.
The SYS_INFO module performs extensive host profiling including: public IP retrieval via ipify.org APIs, CPU model/username/hostname/OS platform/release/architecture enumeration, RAM metrics and uptime, MAC address extraction via os.networkInterfaces(), GPU identification (PowerShell WMI on Windows, lspci/glxinfo on Linux), antivirus detection via WMI queries or process enumeration, domain membership and administrative privilege checks, and Machine Hardware ID retrieval from registry or system files.
## EtherHiding — Blockchain C2 Infrastructure
EtherRAT's most notable innovation is its use of Ethereum smart contracts for C2 address storage and rotation (EtherHiding technique). Two smart contracts have been identified: 0xe26c57b7fa8de030238b0a71b3d063397ac127d3 (eSentire campaign, Windows) and 0x22f96d61cf118efabc7c5bf3384734fad2f6ead4 (Sysdig campaign, Linux). C2 addresses are stored via the setString function and can be rotated by conducting additional blockchain transactions at minimal cost.
The implant queries nine public Ethereum RPC endpoints concurrently (eth.llamarpc.com, mainnet.gateway.tenderly.co, rpc.flashbots.net/fast, rpc.mevblocker.io, eth-mainnet.public.blastapi.io, ethereum-rpc.publicnode.com, rpc.payload.de, eth.drpc.org, eth.merkle.io) and uses majority-vote consensus to determine the authoritative C2 address, preventing single-endpoint poisoning attacks. This architecture makes traditional takedown methods ineffective since C2 addresses reside on immutable, distributed blockchain infrastructure.
## CDN-Like Beacon URLs
Network communications use randomized CDN-like beacon URLs following the pattern: <C2_ADDRESS>/api/<8_HEX>/<UUID>/<8_HEX>.<EXT>?<PARAM>=<BUILD_ID>. File extensions are randomly selected from png, jpg, gif, css, ico, and webp, while query parameters rotate through id, token, key, b, q, s, and v. All communications use HTTPS with TLS 1.3, and the C2 polling interval is 500 milliseconds. Responses exceeding 10 characters are treated as JavaScript code and executed with full Node.js context.
## Delivery Chains
**Windows (ClickFix/IT Support Scam):** Initial access via ClickFix social engineering or Microsoft Teams IT support scams with QuickAssist for unauthorized remote access. Stage 1 uses the LOLBin chain pcalua.exe -> mshta.exe with caret obfuscation to retrieve an HTA script from compromised infrastructure (shepherdsestates.uk). The HTA downloads a Node.js runtime (v18.17.0) and encrypted payloads. Stage 2 decrypts the stager using AES-256-CBC via module._compile() for in-memory execution and establishes HKCU Run key persistence with a random 12-character hex value name. Stage 3 launches EtherRAT via conhost.exe --headless node.exe.
**Linux (React2Shell / CVE-2025-55182):** Exploits an unsafe deserialization vulnerability in React Server Components affecting React 19.x and Next.js 15.x/16.x with App Router. A single HTTP request triggers unauthenticated RCE. A Base64-encoded shell command executes a persistent download loop using curl/wget/python3 fallbacks to retrieve a shell script (s.sh) from 193.24.123.68:3001. The script creates a hidden directory structure in $HOME/.local/share/.05bf0e9b, downloads Node.js v20.10.0, writes encrypted payloa
Weaknesses (CWE)
CWE-502, CWE-94
Detections & IOCs
As of 2026-07-27, this threat has 9 detection rule(s) across Splunk SPL, Microsoft KQL and Sigma, and 36 indicator(s) of compromise. Detection query text and full IOC values are available to authenticated users and programmatically via the Threadlinqs MCP server (Purple tier). View plans.
MALWARE, CRITICAL, threat intelligence, cybersecurity, CVE-2025-55182, T1190, T1566.003, T1059.001, T1059.004, T1059.007, T1204.001, T1202, T1569.002, T1547.001, T1547.013