Claude Code

Ghostcommit Attack: Malicious Prompts Hidden in PNG Images Hijack AI Coding Agents to Steal .env Secrets

A novel supply-chain attack called Ghostcommit allows attackers to embed prompt-injection instructions inside PNG images, bypassing AI-powered code review tools and tricking coding agents into leaking sensitive .env configuration files and API keys. Researchers from the ASSET Research Group demonstrated that direct plaintext instructions are immediately flagged by tools such as Cursor and CodeRabbit, but splitting the payload across an AGENTS.md file and a seemingly innocuous image evades detection. The attack remains dormant until a developer later asks the agent to perform normal development tasks, at which point the agent reads the image, extracts the .env contents byte-by-byte, and outputs them as a long tuple of ASCII numbers. Testing across 11 tool-model combinations revealed that success depends primarily on the runtime framework rather than the underlying LLM, with Cursor and Antigravity leaking secrets while Claude Code successfully blocked the attack in most cases. The team also released an open-source multimodal defense prototype based on Gemma 4 that runs on a single 4 GB GPU and achieved near-perfect detection rates on both known and unknown attack samples.