Year in Review: Top Cybersecurity Trends for Law Firms in 2025

If 2024 was the year of AI curiosity, 2025 was the year of AI consequences. For the legal sector, this year didn't just shift the goalposts; it changed the entire game.

As we close the books on 2025, one statistic stands out above the rest: nearly one in five law firms was impacted by a cyber incident this year.

That isn’t just a "trend"—that is a crisis.

At StrongestLayer, we’ve analyzed the attack data from the past 12 months, and the verdict is clear. The era of relying on secure email gateways (SEGs) and annual compliance training is over. Here is our review of the top cybersecurity trends that defined 2025 for law firms, and why 2026 requires a fundamental shift in strategy.

1. Email is Still the #1 Battlefield

Despite the rise of new communication platforms, email remained the primary attack surface for law firms in 2025.

Why law firms? Because you hold the keys to the kingdom: sensitive client data, merger details, and massive transaction wires. Attackers know that if they can breach a partner's inbox, they can bypass every other firewall you have.

2. The "Impersonation" Epidemic

The majority of incidents this year weren't driven by "hacking" in the traditional sense (breaking code). They were driven by phishing and impersonation.

Attackers in 2025 didn't send malware-laden attachments that your antivirus could catch. They sent plain-text emails that sounded exactly like a Managing Partner or a trusted vendor. They used Generative AI to mimic tone, style, and context perfectly.

The hard truth: Traditional "rule-based" security cannot catch these attacks because there is no malicious link to scan. The threat is in the intent, not the payload.

3. The Failure of "Gateway-Only" Defenses

For years, IT managers relied on the "Castle and Moat" strategy—building a strong gateway around the firm. 2025 proved this model is insufficient.

Once an email lands in an inbox, the gateway's job is done. But modern threats often weaponize after delivery, or use "sleeper" accounts that gateways trust. If your defense stops at the perimeter, you are leaving your internal communications wide open.

4. "Human Firewall" Fatigue

We also saw the limits of relying solely on employees. While training is essential, 2025 showed us that annual training is no longer sufficient to stop hyper-realistic AI phishing.

Expecting a busy associate billing 2,000 hours a year to perfectly analyze every email header is a strategy set up for failure. Humans should be your last line of defense, not your only one.

The CTO’s Perspective: Why We Must Pivot

The data tells us that the old methods aren't just failing; they are obsolete. As Riz, CTO and Co Founder of StrongestLayer, emphasizes, the industry has reached a tipping point where we must look at the problem differently:

"In 2025, email remained the primary attack surface for law firms. Phishing and impersonation drove the majority of incidents, with nearly one in five firms impacted. This made it clear that gateway-only defenses and annual training are no longer sufficient, email security has to reason in real time."

The Shift for 2026: Reasoning in Real-Time

Riz’s insight is the core of our strategy for the coming year.

Old security asks: "Does this email come from a blacklisted IP?" New security  asks: "Does this request make sense given the relationship between these two people?"

To protect your firm in 2026, your security stack needs to move beyond static rules. It needs to understand:

• Context: Who usually talks to whom?
• Intent: Is this urgent request for a wire transfer typical behavior?
• Language: Does this email sound like the sender?

Final Thought

The legal sector is built on trust. In 2025, that trust was under attack like never before. As we move into the new year, law firm leadership must accept that the old tools—gateways and quizzes—are relics of a simpler time.

The future of legal security isn't about building higher walls. It's about building smarter, reasoning defenses that catch what humans miss.

Here’s to a secure and resilient 2026.

Frequently Asked Questions (FAQs)

Q1: Why were law firms specifically targeted by cyberattacks in 2025?

‍Law firms are high-value targets because they hold sensitive client data, merger details, and manage large financial transactions. Attackers know that law firms operate on tight deadlines and high trust, making them vulnerable to Business Email Compromise (BEC) and sophisticated impersonation attacks that bypass standard filters.

Q2: Why are Secure Email Gateways (SEGs) no longer sufficient for law firms?

‍Traditional gateways rely on "rules"—checking for malicious links, attachments, or blacklisted IPs. In 2025, attackers shifted to text-based social engineering using Generative AI. These emails contain no malware and come from "clean" IPs, allowing them to slip past gateways undetected. As noted in our review, defenses must now go beyond the perimeter and analyze intent.

Q3: What does "reasoning in real-time" mean in email security?

‍"Reasoning in real-time" is the shift from static detection to dynamic understanding. Instead of just checking if an email is "safe" or "malicious" based on a list, the security system analyzes the context: Does this sender usually email this person? Is the tone urgent? Is this request typical? It mimics human intuition at machine speed to catch anomalies that rules miss.

Q4: Is employee security awareness training still effective against AI phishing?

‍Training is necessary but insufficient on its own. While it helps employees spot obvious fakes, AI-generated phishing emails are now hyper-realistic and can fool even trained eyes. Relying solely on a "human firewall" creates a single point of failure. Security strategies for 2026 must support human vigilance with AI-driven defense layers.

Q5: What is the biggest cybersecurity trend for law firms in 2026?

‍The biggest trend for 2026 is the adoption of behavioral-based security. Law firms are moving away from legacy "castle-and-moat" architectures toward systems that continuously monitor internal communications for signs of account takeover and lateral movement, ensuring protection even if a threat lands in the inbox.