When One Door Opens for a Hacker, a Dozen More Follow
Cyberattacks rarely stop at one victim. One successful breach can unlock doors across multiple organizations, especially when email is involved. A single compromised account can start a chain reaction with devastating consequences.Â
This is the story of how a single email, sent from a trusted contact, almost compromised one of the top law firms in the country. And it all started with the same breach we detailed in our article on email security. [Read the full story here.]Â
The Law Firm, the Assistant, and the Attachment
Three days after a small B2B business discovered its email had been hacked and used to send fake invoices, the ripple effect had already begun.Â
While scanning the contact list, the hacker noticed something interesting—one of the company’s clients was a large and well-known attorney firm. The hacker saw opportunity. Instead of sending them a fake invoice he sent something else.
Law firms are treasure troves of confidential data. Contracts, identity documents, M&A plans, court strategies—information that can be sold, held for ransom, or used for blackmail. Gaining access to such a firm could be worth much more than a few redirected invoices.Â
So the hacker crafted a follow-up email to a legal assistant at the firm. It appeared to be a routine message: “Here’s the latest version of the delivery contract.” Attached was a PDF with a familiar filename. It came from a known, trusted contact. The legal assistant downloaded it without hesitation.Â
The Trojan Horse Enters the Castle
The document looked normal. But inside it hid a trojan—malware designed to silently install on the victim’s machine, bypassing most antivirus scans. Once active, it started mapping the system, logging keystrokes, and searching for access points to the firm’s internal network.
This kind of malware doesn’t crash systems or steal files immediately. It waits. Observes. Builds access. The longer it remains undetected, the more damage it can do. In this case, the trojan began silently transmitting metadata back to a remote server: file structures, software versions, credentials.
What happened here is not unusual. In fact, it’s textbook.Â
Once an attacker compromises one company, they inherit that company’s trust network—its contacts, communication patterns, and behavioral habits. This gives them a foot in the door of every other organization in that ecosystem.Â
It’s like a domino effect: one company falls to a phishing attack. Their email is hijacked and used to send malware. A contact opens the file, thinking it’s safe. Their system is compromised. From there, it spreads again.Â
Email Security Is a Network Responsibility
Fortunately, the law firm had a robust internal system. A routine security scan an hour later flagged an unknown outbound connection from the assistant’s workstation. Their IT team isolated the machine and began forensics. That trojan hadn’t yet reached deeper parts of the network, but it was close.Â
The breach was contained. But the incident was a wake-up call.  They traced the origin of the email. That’s when they discovered the connection to the B2B business whose email had been hacked days earlier.
If your contacts aren’t secure, your company isn’t either.Â
Email security isn’t just about protecting your own inbox—it’s about protecting the ecosystem you’re part of. When one link in the chain breaks, the entire network becomes vulnerable.Â
That’s why prevention matters. Because by the time you’re responding to an incident, the damage may already be in motion.Â
Protect Your Company—and Everyone You Work With
At Solecreation, we help companies build real resilience against threats like these.Â
We offer:Â
- Phishing and malware awareness training for employeesÂ
- Advanced email security protocols that go beyond basic antivirusÂ
- Incident simulations to test how your organization would respondÂ
- Rapid response playbooks for trojans, ransomware, and phishingÂ
- Risk assessments to map your trust network and identify weak pointsÂ
If your company is part of someone’s contact list, you’re already part of the battlefield. Don’t let someone else’s breach become your crisis.Â
