Incident Response Planning – What to Do When Social Engineering Attacks Succeed
Still think your people are your strongest line of defense?
They might be. But they’re also your biggest risk. And attackers know it.
Social engineering attacks don’t breach firewalls. They bypass them. They exploit trust, emotions, and habits, not code. Whether it’s a cleverly worded phishing email, a fake IT request, or a rogue message from “HR,” the goal is simple: get someone to hand over access.
When that happens, it’s not theory anymore. It’s reality. So, what now?
This post outlines what businesses should do after a social engineering attack gets through. From immediate containment to communication protocols, we’ll walk through how to limit damage, coordinate a fast response, and make your people part of the solution going forward.
Table of Contents:
What Is a Social Engineering Attack?
Social engineering is a form of cybercrime that manipulates people rather than systems. Instead of exploiting technical flaws, attackers manipulate psychology (trust, urgency, fear, or curiosity) to gain access or information. It’s subtle. Often invisible. And wildly effective.
It can take many forms:
- Phishing emails
- Pretexting (fake scenarios or identities)
- Tailgating (physical access through impersonation)
- Vishing (voice-based scams)
- Business email compromise (BEC)
Unlike technical attacks, these don’t rely on software vulnerabilities. They target human ones.
You can’t prevent every incident, but you can be better prepared.
From endpoint to phishing, our cybersecurity solutions help Canadian businesses defend better and recover faster. Learn more.
When Social Engineering Succeeds: First 24 Hours
The first 24 hours after discovering a successful social engineering breach will define how much damage your organization takes on. Every minute counts. Your ability to react quickly and clearly can differentiate between an isolated issue and a full-blown crisis.
Here’s what your team should focus on immediately:
Step 1. Isolate the Breach
If an endpoint was compromised, remove it from the network, lock down any affected user accounts, change passwords, and reset authentication credentials. Quick isolation can stop an attacker from pivoting to other systems.
Step 2. Activate Your Incident Response Plan
Assuming you have one, now’s the time to use it. Your plan should outline:
- Who takes the lead
- Roles and responsibilities of team members
- Communication protocols (internal and external)
- Escalation paths for legal, compliance, and executive teams
No plan? Start documenting actions anyway. You’ll need it for post-incident review.
Step 3. Preserve Evidence
Don’t wipe compromised systems too soon. Instead, capture logs, screenshots, and network activity. This evidence will help with forensic analysis, attribution, and regulatory reporting.
Step 4. Notify Stakeholders
This might include:
- IT security leadership
- Legal and compliance
- Senior executives
- Third-party vendors (if affected)
Early communication reduces confusion and helps coordinate the response.
Read More: Understanding Identity Threat Detection (Why Your Business Needs ITDR Now)
Containment Without Chaos
Containing an incident doesn’t mean hitting the panic button. It’s about measured, effective decisions that stop the attack from spreading further without grinding your business to a halt.
Containment doesn’t mean panic. It means you are taking deliberate action to limit the attacker’s reach.
What to do:
- Disable compromised user accounts
- Revoke shared credentials (admin, API keys, remote access tokens)
- Apply network segmentation to quarantine suspicious traffic
- Monitor internal systems for lateral movement or privilege escalation attempts
Containment should be precise. Overreaction can disrupt operations, while underreaction leaves gaps.
Can’t contain credential-based breaches before they spread?
Learn how Identity Threat Detection and Response (ITDR) stops attackers after they’ve gotten in. Real-time detection. Smarter identity controls. Explore ITDR solutions.
Communication: Getting It Right Under Pressure
The wrong message at the wrong time can do more damage than the attack itself. Internal confusion, external backlash, and regulatory penalties are all risks when communication breaks down.
When incidents happen, people want answers. Fast. But not every update should come out right away. Misinformation creates just as much chaos as silence.
Best practices for incident communication:
- Use a single source of truth (your security team, not a group chat)
- Draft clear, jargon-free internal updates
- Confirm facts before issuing any external statement
- For high-risk incidents, prepare a statement for clients or partners, especially if their data might be affected
Should you notify regulators or privacy commissioners?
Yes, if there’s potential data exposure under Canadian privacy law (PIPEDA) or sector-specific regulations. Timely disclosure may be required within a specific window. Don’t wait too long to seek legal guidance.
Post-Incident Investigation: Find the Root Cause
Once the fire is out, the real work begins. Investigating how the breach happened, and why it wasn’t caught sooner, helps prevent a repeat. You’re not just patching holes. You’re strengthening the foundation.
Conduct a post-incident investigation that includes:
- Timeline of events from initial compromise to detection
- Attack vector analysis (what the attacker exploited)
- Affected systems and data
- Detection gaps (why didn’t your tools catch it earlier?)
- Human factors (how the attacker manipulated behaviour)
Involve both technical and non-technical stakeholders. Many social engineering attacks exploit cross-functional weaknesses: poor training, unclear escalation paths, or unvetted third-party tools.
Lessons Learned: Build a Smarter Defence
If you don’t take away anything new from an incident, you’ve missed a huge opportunity. The best security teams treat every breach as a chance to sharpen tools, people, and processes.
Your post-mortem should answer:
- How can we strengthen email and identity controls
- Do our employees know what suspicious activity looks like
- Are we investing in continuous testing, like simulated phishing campaigns
- Did our incident response plan work, or did we scramble
Turn insights into action. Update policies, refresh employee training, and refine your detection playbooks. Threat actors evolve. So should you.
Read More: The Future of Social Engineering: Cyber Threats 2025 and Beyond
Leaks don’t always start with malware — sometimes they start with misplaced trust.
Protect your data with layered, policy-driven controls that reduce human error and insider threats. Learn more about Information security services.
Training Your Team for the Next Attack
One-off training won’t cut it. Your people need repetition, context, and up-to-date threat examples. Security awareness should be part of your company’s culture, not a box you check.
People can’t spot what they don’t recognize.
Reinforce with:
- Realistic phishing simulations
- Gamified learning (cybersecurity challenges, quizzes)
- Microlearning videos (2–5 minute lessons)
- Clear reporting channels (“See something? Say something.”)
The goal isn’t fear. It’s awareness. And the best training connects everyday behaviour to real-world consequences.
Don’t Go It Alone: Partnering with an MSSP
Cybersecurity doesn’t have to be tackled alone. If your internal resources are already stretched thin, a trusted partner can help your team move faster and respond smarter.
If this all sounds overwhelming, it’s because incident response is hard to do solo. Managed Security Service Providers (MSSPs) bring:
- 24/7 monitoring and threat detection
- Expert-led response teams
- Proven playbooks for social engineering recovery
- Post-incident reporting and guidance
An MSSP acts as an extension of your team. They reduce dwell time, streamline containment, and help you bounce back faster.
Read More: Learn how IT MSSPs Handle Cybersecurity Threats.
Curious how MSSP support could fit your business model? Start the conversation with DNSnetworks’ cybersecurity specialists here.
What Sets Resilient Teams Apart
Resilience isn’t about being perfect. It’s about being prepared. The best organisations don’t avoid every incident. They recover faster, learn more, and come back stronger each time.
Even the best defences slip. Social engineering thrives on human error, and no filter, firewall, or AI model can stop everything. What sets resilient organisations apart is how they respond under pressure.
A coordinated, well-rehearsed incident response doesn’t just limit damage. It protects your reputation, preserves stakeholder trust, and strengthens your future defences. The key is to prepare before the breach, not after.
Want expert support to build or test your response plan? Talk to DNSnetworks today about incident response planning, staff training, and identity-based threat defence that keeps your business ready for whatever comes next.