Performing Vulnerability Scanning With Nessus

Performing Vulnerability Scanning With Nessus

Overview

Cybersecurity skill for performing vulnerability scanning with nessus. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "performing vulnerability scanning with nessus"

• "Performs authenticated and unauthenticated vulnerability scanning using Tenable "

• Conducting initial vulnerability assessment during the reconnaissance phase of a penetration test

• Performing periodic vulnerability scans to maintain compliance with PCI-DSS (requirement 11.2), HIPAA, or SOC 2 standards

• Validating that remediation efforts have successfully addressed previously identified vulnerabilities

• Establishing a baseline of known vulnerabilities before targeted manual exploitation

• Auditing patch compliance and configuration drift across server and workstation fleets

Do not use as a substitute for manual penetration testing, against systems without written authorization, or against fragile systems (medical devices, legacy SCADA) where scanning may cause service disruption.

When NOT to Use

• When you lack proper authorization for testing
• For production systems without change management
• When the task requires legal or compliance expertise beyond technical scope

Prerequisites

• Tenable Nessus Professional or Nessus Expert with current plugin updates (plugins should be less than 24 hours old)
• Network connectivity to all target hosts on all ports (no firewall restrictions between scanner and targets)
• Administrative credentials for authenticated scanning (domain admin or local admin for Windows, root/sudo for Linux, SNMP community strings for network devices)
• Target IP ranges and hostnames documented in the scope agreement
• Change management approval for scanning during authorized windows

Workflow

# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs(text: str) -> dict:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}

1. Plan Operations — Define objectives, scope, and success criteria for vulnerability scanning operations.
2. Prepare Environment — Set up tools, access, and data sources required for vulnerability scanning.
3. Execute Core Workflow — Use nessus to perform vulnerability scanning operations following established procedures.
4. Validate Results — Verify that results meet quality standards and objectives.
5. Report Findings — Document results, observations, and recommendations.
6. Follow Up — Track remediation actions and verify fixes where applicable.

Tools

• nessus — Primary tool for this skill
• Analysis Platform — Data processing and visualization
• Collaboration Tools — Team coordination and knowledge sharing

Process

1. Reconnaissance — Gather target information, identify attack surface, enumerate services
2. Analysis/Exploitation — Execute the technique, analyze results, document findings
3. Reporting — Document IOCs, write findings, provide remediation recommendations

Verification

• All vulnerability scanning procedures executed completely and documented
• Findings validated against multiple data sources
• False positives identified and filtered
• Results documented with evidence and timestamps
• Recommendations provided with risk-based prioritization

Anti-Rationalization Table