A file in Downloads folder made an AI coding assistant install malware

Forever caught an AI coding assistant installing the malicious function-color package from the MALFEX campaign after reading an instruction file in a customer's Downloads folder. In tests, Codex ran the malware and persisted the attacker's server, while a Claude Code attack succeeded about half the time.

• An attacker planted a Downloads file instructing the assistant to install the function-color package from the MALFEX campaign
• In an isolated test, Codex downloaded and ran the malware and changed settings to load the attacker's server
• The Claude Code attack worked about half the time and exposed a login token
• Forever advises keeping assistants out of Downloads and leaving sandboxes and approvals enabled