Threat Advisory

GlassWASM Malware Hidden in Open VSX Extensions

Threat: Malware
Targeted Region: Global
Targeted Sector: Technology & IT
Criticality: High
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EXECUTIVE SUMMARY:

Malicious Open VSX extensions, specifically exargd/[email protected] and noellee-doc/[email protected], were discovered to be trojanized with WebAssembly malware embedded in a renamed TinyGo loader. The malware uses ChaCha20 string encryption to conceal its command-and-control infrastructure, which is resolved from the Solana mainnet blockchain via getSignaturesForAddress and getTransaction RPC calls. The second-stage host is retrieved from an on-chain SPL Memo instruction and used to build a cross-platform download-and-execute command via child_process in a script payload. The malware's use of WebAssembly as a stager suggests a new pivot to binary loading for obfuscation purposes. The malware's ChaCha20 string encryption makes it difficult to detect by signatures simply using natural language or readable strings.[/subscribe_to_unlock_form]

EXECUTIVE SUMMARY:

Malicious Open VSX extensions, specifically exargd/[email protected] and noellee-doc/[email protected], were discovered to be trojanized with WebAssembly malware embedded in a renamed TinyGo loader. The malware uses ChaCha20 string encryption to conceal its command-and-control infrastructure, which is resolved from the Solana mainnet blockchain via getSignaturesForAddress and getTransaction RPC calls. The second-stage host is retrieved from an on-chain SPL Memo instruction and used to build a cross-platform download-and-execute command via child_process in a script payload. The malware's use of WebAssembly as a stager suggests a new pivot to binary loading for obfuscation purposes. The malware's ChaCha20 string encryption makes it difficult to detect by signatures simply using natural language or readable strings.[emaillocker id="1283"]

Once deobfuscated, the module's purpose is unambiguous: it polls the Solana mainnet JSON-RPC API for transactions sent to an attacker-controlled wallet, reads the attacker's instructions out of the on-chain SPL Memo field, and uses that to build and execute an OS-specific download-and-execute command via Node's child_process. The Solana blockchain is used as a takedown-resistant command-and-control (C2) dead-drop: there is no hardcoded server to seize or sinkhole, and the operator can rotate second-stage infrastructure simply by posting a new transaction.

The tradecraft in this module overlaps significantly with the GlassWorm supply-chain campaign, which compromised 400+ components across npm, the VS Code Marketplace, Open VSX, and GitHub between and. The use of Solana transaction memos sent to a watched wallet as a takedown-resistant C2 dead-drop that resolves a rotating second-stage host is a defining innovation of GlassWorm. This sample matches the vector exactly: a single account published identity-cloned trojanized extensions to Open VSX under impersonated namespaces (ExarGD, noellee-doc) on /10, reusing the names, versions, and repo links of legitimate, verified VS Code Marketplace extensions.

THREAT PROFILE:

Tactic Technique Id Technique Sub-technique
Initial access T1195 Supply Chain Compromise -
Initial access T1195.002 Supply Chain Compromise Compromise Software Supply Chain
Execution T1059.001 Command and Scripting Interpreter PowerShell
Execution T1059.003 Command and Scripting Interpreter Windows Command Shell
Defence Evasion T1027.002 Obfuscated Files or Information Software Packing
Defence Evasion T1140 Deobfuscate/Decode Files or Information -
Command and control T1071.001 Application Layer Protocol Web Protocols
Command and control T1573.001 Encrypted Channel Symmetric Cryptography
Exfiltration T1041 Exfiltration Over C2 Channel -

MBC MAPPING:

Objective Behavior ID Behavior
Command & Control B0030 C2 Communication
Anti-Static Analysis B0032 Executable Code Obfuscation
Execution E1204 User Execution
Impact B0022 Remote Access
Exfiltration E1020 Automated Exfiltration
Anti-Static Analysis E1027 Obfuscated Files or Information
Command & Control E1105 Ingress Tool Transfer

REFERENCES:

The following reports contain further technical details:
https://socket.dev/blog/glasswasm-malware-open-vsx-extensions

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