By Joe Seanor, CISSP | Cyber Investigator & Network Security Expert
“We’ve been hacked. What do we do now?”
That’s the call no business ever wants to make—but the one many do. As a cyber investigator, I’ve been on the other side of that line more times than I can count. And I can tell you: what happens next can make or break your company’s future.
Cyber investigations aren’t about “hacking back” or cinematic digital chases. They’re about uncovering the truth—step-by-step—under pressure, with every second counting.
Today, I’ll walk you through what really happens during a professional cyber investigation—and why it’s more important than ever to have a response plan in place.
Phase 1: The Initial Triage – “Is This Real?”
When a company first suspects something is wrong, emotions run high.
The first job of the investigator is to determine if it’s an actual incident, not a false alarm.
Key Steps:
- Interview the reporting party (often IT or a staff member)
- Collect screenshots, logs, error messages, or unusual emails
- Check for indicators of compromise (IOCs): unknown logins, suspicious traffic, strange processes
Goal: Confirm the breach and begin containment immediately if active.
Phase 2: Containment – “Stop the Bleeding”
If we confirm that there’s an ongoing attack (or remnants of one), containment is priority #1.
This could mean:
- Disconnecting affected systems from the network
- Changing passwords and revoking access tokens
- Isolating compromised accounts or devices
Real-World Example:
In a ransomware case I investigated, we caught the attacker mid-encryption and cut off their access within 20 minutes. Fast action saved the client from full data loss.
Phase 3: Forensic Evidence Collection
Now it’s time to dig deep—without destroying evidence.
We create forensic images (exact digital copies) of affected systems. We look for:
- Malware implants
- Command-and-control communications
- Registry changes
- Suspicious user accounts
- Log manipulation
We also pull network logs, firewall records, and endpoint data to track attacker behavior.
Goal: Understand the scope, timeline, and impact of the breach.
Phase 4: Attribution & Intent
This is where the real detective work begins.
We piece together the attack chain:
- How did they get in (phishing, vulnerability, credential theft)?
- What did they access or exfiltrate?
- Are they still in the network?
Sometimes we can identify the attacker group by IP addresses, malware signatures, or tactics—especially if they match known threat actor profiles (like FIN7 or Lazarus Group).
Goal: Determine who did it, why, and whether it’s targeted or opportunistic.
Phase 5: Remediation & Recovery
Once we have a clear picture, we help the client:
- Clean infected systems or rebuild from clean backups
- Patch exploited vulnerabilities
- Improve firewall, email, and endpoint defenses
- Roll out employee training if human error was involved
Bonus Tip: Never just “wipe and move on.” If you don’t learn from the breach, it’s likely to happen again.
Phase 6: Reporting & Legal Coordination
Most investigations wrap with a full forensic report that includes:
- Timeline of the incident
- Attack vectors used
- Data affected
- Actionable recommendations
Depending on the breach type, we may also:
- Notify regulatory bodies (like HIPAA or GDPR agencies)
- Coordinate with law enforcement (e.g., FBI Cyber Division)
- Support breach notification to customers or partners
Final Thoughts: Cyber Incidents Are Inevitable—Response Isn’t Optional
You can’t always stop a breach. But you can control how fast you respond, how well you contain it, and how quickly you recover.
Most businesses wait until it’s too late to think about cyber investigations. Don’t be one of them.
Plan now, so when—not if—the breach happens, you’re ready.
Stay secure,
Joe Seanor
CISSP | Private Cybersecurity Consultant