Analyzing Network Traffic With Wireshark

Analyzing Network Traffic With Wireshark

Overview

Cybersecurity skill for analyzing network traffic with wireshark. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "analyzing network traffic with wireshark"

• "Captures and analyzes network packet data using Wireshark and tshark to identify"

• Investigating suspected network intrusions by examining packet-level evidence of command-and-control traffic, data exfiltration, or lateral movement

• Diagnosing network performance issues such as retransmissions, fragmentation, or DNS resolution failures

• Analyzing malware communication patterns by capturing traffic from sandboxed or isolated hosts

• Validating firewall and IDS rules by confirming what traffic is actually traversing network segments

• Extracting files, credentials, or indicators of compromise from captured network sessions

Do not use to capture traffic on networks without authorization, to intercept private communications without legal authority, or as a substitute for full-featured SIEM platforms in production monitoring.

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

• Wireshark 4.0+ and tshark command-line utility installed
• Root/sudo privileges or membership in the wireshark group for live packet capture
• Network interface access (physical NIC, span port, or network tap) to the monitored segment
• Sufficient disk space for packet capture files (estimate 1 GB per minute on busy gigabit links)
• Familiarity with TCP/IP protocols, HTTP, DNS, TLS, and SMB at the packet level

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. Scope the Analysis — Define what network traffic artifacts or data sources to examine and the investigation timeline.
2. Preserve Evidence — Create forensic copies of relevant data. Maintain chain of custody documentation.
3. Extract Key Indicators — Use wireshark to parse and extract relevant network traffic data points from collected artifacts.
4. Correlate Findings — Cross-reference extracted data with other sources (threat intel, logs, timelines).
5. Build Timeline — Construct a chronological sequence of events related to network traffic.
6. Document Analysis — Write findings report with evidence, conclusions, and recommendations.

Tools

• wireshark — Primary tool for this skill
• Forensic Toolkit — Evidence collection and analysis
• Timeline Tools — Chronological event reconstruction
• Log Analysis Platform — Centralized log parsing and search

Process

1. Scope — Define research questions, identify data sources, set time boundaries
2. Gather — Collect data from primary sources, APIs, and public records
3. Synthesize — Analyze findings, identify patterns, produce actionable report

Verification

• All network traffic 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