Conducting Phishing Incident Response

Conducting Phishing Incident Response

Overview

Cybersecurity skill for conducting phishing incident response. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "conducting phishing incident response"

• "Responds to phishing incidents by analyzing reported emails, extracting indicato"

• A user reports receiving a suspicious email via the phishing report button or abuse mailbox

• Email gateway detects a malicious email that bypassed initial filtering

• Threat intelligence indicates an active phishing campaign targeting the organization

• A user confirms they clicked a link or opened an attachment from a suspicious email

• Credentials have been entered on a suspected phishing page

Do not use for business email compromise (BEC) involving compromised internal accounts; use BEC response procedures which focus on account takeover investigation.

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

• Email security gateway with message trace and quarantine capabilities (Microsoft Defender for Office 365, Proofpoint, Mimecast)
• Microsoft 365 admin access or Google Workspace admin for mailbox search and purge
• Malware sandbox for attachment and URL analysis (ANY.RUN, Joe Sandbox, Hybrid Analysis)
• Email header analysis tools (MXToolbox Header Analyzer, Google Admin Toolbox)
• Identity provider access for account remediation (Azure AD, Okta, Duo)
• Phishing report intake process (dedicated mailbox or integrated report button)

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 phishing incident response 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 — Parse and extract relevant phishing incident response 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 phishing incident response.
6. Document Analysis — Write findings report with evidence, conclusions, and recommendations.

Tools

• Forensic Toolkit — Evidence collection and analysis
• Timeline Tools — Chronological event reconstruction
• Log Analysis Platform — Centralized log parsing and search

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 phishing incident response 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