Cron Scheduler

• Outcome: Review
• Latest audit: May 28, 2026 · 7:55 AM UTC
• Version: 1.0.0

Overview

This skill is not deceptive, but it gives an agent broad power to create, remove, and persist scheduled system commands with too few built-in safeguards.

Install only if you intentionally want the agent to manage real cron jobs on your machine. Before applying changes, review the exact cron line, back up the current crontab, require explicit approval, avoid broad deletion patterns, use absolute paths, and periodically audit or remove jobs because they can keep running after the conversation ends.

SkillSpector

By NVIDIA

Vulnerability Patterns

• Data Exfiltration: External Transmission, Env Variable Harvesting, File System Enumeration
• Rogue Agent: Self-Modification, Session Persistence
• Prompt Injection: Instruction Override, Hidden Instructions, Exfiltration Commands
• Privilege Escalation: Excessive Permissions, Sudo/Root Execution, Credential Access
• Supply Chain: Unpinned Dependencies, External Script Fetching, Obfuscated Code

Findings (7)

Missing User Warnings

Medium

• Confidence: 90% confidence
• Finding: The skill explicitly instructs the agent to add, edit, and remove cron jobs, which are persistent system changes that can alter behavior long after the session ends. Because it provides direct modification commands without clear confirmation, scope limits, or warnings about persistence and system impact, it creates a real safety risk of unintended scheduled execution or disruption.

Missing User Warnings

Medium

• Confidence: 86% confidence
• Finding: The examples include destructive and system-affecting actions such as deleting files from /tmp and restarting services automatically. In a scheduling skill, these are especially risky because automation amplifies mistakes: a bad command can repeatedly delete data or repeatedly disrupt services without further user interaction.

Session Persistence

Medium

• Category: Rogue Agent

Content

### Add a cron job
```bash
# Add to user crontab
(crontab -l 2>/dev/null; echo "SCHEDULE COMMAND") | crontab -

# Common schedules:

• Confidence: 97% confidence
• Finding: crontab (crontab -l 2>/

Session Persistence

Medium

• Category: Rogue Agent

Content

### Remove a cron job
```bash
# Edit crontab interactively
crontab -e

# Or remove a specific line
crontab -l | grep -v "PATTERN_TO_REMOVE" | crontab -

• Confidence: 83% confidence
• Finding: crontab -e

Session Persistence

Medium

• Category: Rogue Agent

Content

crontab -e

# Or remove a specific line
crontab -l | grep -v "PATTERN_TO_REMOVE" | crontab -
```

### Check cron logs

• Confidence: 90% confidence
• Finding: crontab -l

Session Persistence

Medium

• Category: Rogue Agent

Content

### Environment variables in cron
```bash
# Cron runs with minimal environment. Set what you need:
(crontab -l 2>/dev/null; echo "PATH=/usr/local/bin:/usr/bin:/bin
SHELL=/bin/bash
0 2 * * * /home/user/backup.sh >> /var/log/backup.log 2>&1") | crontab -
```

• Confidence: 95% confidence
• Finding: crontab -l

Session Persistence

Medium

• Category: Rogue Agent

Content

## Examples

**User:** "Run my backup script every night at 2am"
→ `(crontab -l 2>/dev/null; echo "0 2 * * * /home/user/backup.sh >> /var/log/backup.log 2>&1") | crontab -`

**User:** "Check disk space every hour and alert me if it's over 80%"
→ Create a check script + cron job

• Confidence: 96% confidence
• Finding: crontab -l

VirusTotal

66/66 vendors flagged this skill as clean.

Static analysis

No suspicious patterns detected.