XCSSET v40: From Xcode Supply Chain to Memory-Resident and Browser/Telegram Hijacking

XCSSET v40: From Xcode Supply Chain to Memory-Resident and Browser/Telegram Hijacking 1. Basic Information Article Title : The Xcode Assassin Returns: A Deep Dive Into the Latest XCSSET Version Publisher : Unit 42 Publication Date : 2026-07-31 Severity : High Original Source : https://unit42.paloaltonetworks.com/xcsset-v40-malware-analysis/ Related Malware : XCSSET v40 Threat Actor : XCSSET operators (Unattributed) CVE : None Products/Environments : macOS, Xcode, Google Chrome, Telegram Related Sources Microsoft's 2025 XCSSET Analysis 2. Executive Summary A macOS supply chain attack that starts with building a legitimate Xcode project. After C2 approval, a multi-stage loader executes 17 modules in memory to hijack Chrome sessions and the Telegram app. 3. Attack Flow Xcode Supply Chain Infection Attackers inject a malicious run-script into a legitimate Xcode project on platforms like GitHub. A developer builds the project locally and runs the script, which is obfuscated using Hex/Base64. The script uses curl to connect to /a on the C2 server with p=xcode_phase , sending system info like uname and whoami . If the C2 server approves the target, the bash stager checks the serial number and creates /tmp/r and/or /tmp/p.app . It uses osascript to run the boot orchestrator in memory, then deletes the temporary files and staging processes. The boot orchestrator downloads encrypted modules from /s/<encoded_module_name> to steal browser data, log keys, access the clipboard, and exfiltrate information. It self-replicates into other existing Xcode projects on the infected machine to spread to the next developer and build artifacts. Chrome/Telegram Hijacking It wraps legitimate Chrome in a malicious wrapper to restart the boot orchestrator every time Chrome launches. It launches Chrome with CDP (Chrome DevTools Protocol) enabled arguments and a fixed local port. chrome_remote connects to CDP to run arbitrary JavaScript, extract cookie tokens, and control existing sessions. Anoth