Introduction
Cyberattacks are no longer rare events—they’re a daily reality. Behind every headline is a story filled with missed warnings, clever attackers, and valuable lessons. In this article, we break down a real-world cyberattack step by step to understand exactly how it unfolded and what could have been done to stop it.
Case Study: The Attack on a Mid-Sized Financial Firm
Industry: Finance
Employees: ~250
Impact: Data breach, operational disruption, and reputational damage
Phase 1: Initial Access via Phishing
The attackers sent a well-crafted phishing email that appeared to come from the company’s HR department. It contained a link to a fake benefits document, hosted on a lookalike domain.
What went wrong:
- No email filtering for spoofed domains
- Employees weren’t trained to spot phishing
- MFA was not enforced on internal systems
Prevention tip:
- Implement advanced email filtering and domain protection
- Run phishing awareness campaigns
- Enforce MFA on all internal and cloud services
Phase 2: Credential Harvesting
Once the employee entered their credentials into the fake site, attackers immediately used them to access the VPN portal.
What went wrong:
- VPN was accessible without MFA
- No alerts for logins from unfamiliar IP addresses
Prevention tip:
- Use MFA for all remote access
- Geo-fencing and behavioral anomaly detection on VPN usage
Phase 3: Privilege Escalation
The attackers quickly moved from a standard user account to an admin role by exploiting a known vulnerability in a legacy endpoint management tool.
What went wrong:
- The system was unpatched
- No monitoring for privilege elevation events
Prevention tip:
- Patch management process with strict SLAs
- Monitor and alert on privilege changes in real time
Phase 4: Lateral Movement
Using compromised credentials and tools like PsExec and PowerShell, the attackers moved laterally across multiple systems. They collected sensitive data and installed backdoors.
What went wrong:
- Lack of segmentation in the internal network
- PowerShell activity was not logged or restricted
- No EDR solution in place to detect malicious movement
Prevention tip:
- Use network segmentation to contain breaches
- Log and monitor PowerShell usage
- Deploy EDR with behavioral analytics
Phase 5: Exfiltration and Persistence
After locating sensitive financial and client data, the attackers exfiltrated it to a remote server over HTTPS and created persistence mechanisms to maintain access.
What went wrong:
- No data loss prevention (DLP) tools in place
- Outbound traffic was not inspected
- Persistence mechanisms were not detected
Prevention tip:
- Deploy DLP and inspect outbound traffic
- Monitor registry, scheduled tasks, and service creation for signs of persistence
Key Takeaways
- Humans are the weakest link – Continuous phishing training is a must.
- MFA is critical everywhere – Especially for VPNs, admin portals, and cloud accounts.
- Patch or perish – Unpatched software is one of the easiest paths to privilege escalation.
- Visibility is everything – Without logging and monitoring, attackers move freely.
- Zero trust is the future – Assume breach, limit access, and verify constantly.