Security audit

Expense Tracker

Security checks for vulnerabilities and agentic risk

Overview

This expense-tracking skill is mostly upfront about what it does, but it sets up recurring automation and sends financial data to a hardcoded Google Sheet using local credentials.

Review this carefully before installing. It is designed to keep asking for expenses, write local ledger files, and sync those financial records to a specific Google Sheet using a local Google service-account credential. Only use it if you control the sheet and credential, understand the recurring jobs it will create, and have a way to disable the cron jobs and external sync.

A.I.G

Vulnerability Patterns

System PersistenceInstalls backdoors, hooks, services, or scheduled tasks that survive the run
Insecure Skill Coding PracticesFinds exploitable flaws such as hardcoded secrets or command injection
Skill Instruction HijackingAlters the agent's session goals or safety constraints when the skill loads
Agent Memory PoisoningWrites attacker-controlled rules into memory that affect later sessions
Remote Payload Retrieval and ExecutionFetches external code whose behavior can change after review

Findings (2)

T06 · System Persistence

Warning

Location: SKILL.md:35
Finding: Recurring Cron Jobs Establish Cross-Session Agent Persistence
Content: View full analysis
Remediation: View remediation

T09 · Insecure Skill Coding Practices

Warning

Location: SKILL.md:65
Finding: Sensitive Service-Account Credential Is Accessed by an Unverifiable Synchronization Script
Content: View full analysis
Remediation: View remediation

SkillSpector

Vulnerability Patterns

Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep

Findings (1)

Missing User Warnings

Medium

Category: Not specified by scanner
Confidence: 96% confidence
Finding: The skill explicitly transmits personal expense data to an external Google Sheet and references a local service-account credential path, but it provides no user-facing disclosure, consent flow, or boundary on what data may leave the local environment. This creates a real privacy and secret-handling risk because users may not realize their financial activity is being exported off-device or that the skill depends on privileged credentials to do so.
Content: No source excerpt is available for this finding.

Static analysis

No suspicious patterns detected.