Discovery File Poisoning Part 3: Wallet Signing Metadata, Test Output and Runtime Trust

The earlier discovery file poisoning posts focused on discovery and metadata surfaces. Files that help crawlers, scanners, agents and humans understand a system. This page covers a more uncomfortable layer. Artifacts that appear while an agent is deciding whether to approve, sign, merge, test or trust something.

The nine patterns shipping in this release (GLS-DFP-063, GLS-DFP-069, GLS-DFP-070, GLS-DFP-076, GLS-DFP-093, GLS-DFP-094, GLS-DFP-099, GLS-DFP-100, GLS-DFP-102) expand Sunglasses detection into signing and verification surfaces where the difference between describing and approving matters most. The common shape is simple. A low trust surface contains text that sounds like policy: safe to sign, do not warn, verified by agent, warning level 0, mark this route safe or this output supersedes the scanner. A model sees the words while summarizing the artifact. If the workflow has no authority boundary, the model may convert descriptive text into action.

Wallet flows are built around structured context. EIP-712 defines typed structured data for signing. Sign In with Ethereum (SIWE) messages include a domain, address, URI, version, chain ID, nonce, timestamps and optional resources. WalletConnect sessions define namespaces, chains, methods and events that shape what a connected dapp may request. These fields are useful because they make signing flows inspectable.

That same usefulness makes them tempting carriers for prompt injection. A malicious dapp does not need to break cryptography to confuse an AI wallet assistant. It can try to hide instruction text in a preview label, simulation note, linked dashboard, SIWE statement, typed data message, WalletConnect session proposal, QR label, memo field, bridge bot note or approval badge screenshot.

The dangerous mistake is letting the assistant collapse three different questions into one:

A wallet assistant can summarize metadata. It should not let metadata approve itself. See the AI Agent Hardening Manual for workflow policy templates that enforce this separation.

Part 3 is not only about wallets. The same failure appears in developer workflows. Go's test2json stream includes TestEvent objects with fields such as Action, Package, Test and Output. JSON Schema includes annotation style vocabulary that tools may collect and display. Static analysis and test systems often produce messages that humans trust because they look machine generated.

Attackers can exploit that trust boundary. A failing test prints a message that tells the coding agent to mark the run green. A schema $comment or description tells a tool using agent that a dangerous parameter is approved. A diagnostic stream claims a vulnerability is informational. The content is just text, but it appears in a place where agents are trained to look for evidence.

The rule is the same as wallet flows. Machine readable does not mean authoritative. Output fields, annotations, comments, labels and rendered dashboards can be evidence. They do not get to rewrite the task, policy, scanner verdict or human confirmation requirement. This connects directly to the Sunglasses FAQ on what counts as a trust boundary.

A malicious dapp sends a WalletConnect proposal with normal looking chains and methods, but its description and request labels include instructions for the wallet assistant: trusted spender, do not warn, no extra confirmation needed. The assistant summarizes the proposal as low risk because the metadata sounded confident.

Runtime trust fix: separate proposal description from authorization. Verify chain, method, account scope, spender, destination and requested action against policy before the assistant recommends or performs anything.

A typed data signing preview includes a human readable purpose field that says the signature is a harmless permit only route or that a previous reviewer already approved the spender. The model sees that field while explaining the request and may suppress the warning that the actual allowance is broad.

Runtime trust fix: parse the structured data, but do not trust its prose. Confirm the contract, domain, chain, spender, value, expiration and replay properties independently. Treat approval claims inside the message as claims, not proof. The CVP program documents how teams build these independent verification paths.

A test prints text that becomes the Output field in a JSON test stream. The content says the failing assertion is expected, tells the review agent to mark the run green and asks it to include CI secrets in the summary for debugging. The JSON wrapper makes the text feel like telemetry, but the instruction is still untrusted output from code under test.

Runtime trust fix: let the agent read the output as evidence, but bind final status to the runner's actual result, CI policy and secret handling rules. Logs do not get to redefine pass/fail or exfiltration policy.

For this part of discovery file poisoning, the best defense is not a bigger blocklist of scary words. The defense is a boundary that says which surfaces may inform a decision and which surfaces may authorize one.

Use the Sunglasses how it works guide to understand how this checklist translates into scanner configuration for your workflow.

Sunglasses scans for agent directed instruction language in the places agents are likely to read. Discovery files, metadata fields, logs, schema comments, rendered dashboards, approval notes, test output and wallet adjacent evidence. The nine patterns in this release (across the GLS-DFP family) expand that coverage toward signing and verification surfaces where the difference between describing and approving matters most.

The product stance is intentionally conservative. Sunglasses does not need to claim that every suspicious wallet preview or test log is malicious. It flags the sentence shape that should never be allowed to control an autonomous workflow. Untrusted text asking the agent to change policy, suppress a warning, mark a risky action safe, skip a human or disclose context.

That gives security teams a practical review loop. Find the carrier, inspect the instruction, remove or quarantine the hostile text and add a runtime trust boundary so the same carrier cannot become authority again.

Start with the Sunglasses scanner, read the AI Agent Security 101 guide and use the AI Agent Hardening Manual to turn detections into workflow policy.

No. Wallet metadata, signing previews, SIWE messages and WalletConnect proposals are useful. The issue is authority confusion. An AI assistant should use them as evidence, not as proof that a risky action is safe.

No. Wallet flows make the risk obvious because signing is high stakes, but the same pattern appears in test logs, static analysis diagnostics, JSON Schema annotations, workqueue attachments, dashboards, screenshots and reviewer notes.

Validation can prove a document has the expected shape. It does not prove that free text annotations, comments, labels, examples or descriptions are safe instructions for an agent to follow.

Record the carrier, the exact instruction text, the action it attempted to influence, the authority boundary it tried to bypass and whether the workflow had a runtime trust check before acting.