Ransomware Insider Tactics: AI Defences for UK SMEs

Ransomware isn’t just “hackers breaking in” anymore. NCC Group reported a 13% rise in recorded ransomware attacks in December 2025, and the detail that should worry most UK small businesses isn’t the encryption—it’s the recruitment.

Ransomware-as-a-service (RaaS) groups are increasingly trying to buy access from employees, contractors, and trusted partners instead of battling through patched systems and security tools. That’s not a technical problem first. It’s a people-and-process problem—one that quickly becomes a national resilience issue when enough small suppliers, agencies, and service firms get hit and larger UK organisations feel the knock-on effects.

This post sits in our National Security & Defence series because the front line isn’t just government and critical infrastructure. It’s also the thousands of UK SMEs that make up supply chains, local services, and day-to-day economic continuity. If your business is adopting AI tools for marketing, customer service, recruitment, or finance, you’re expanding productivity—but you’re also expanding your attack surface. The good news: some of the same AI capabilities can be used to spot and stop modern ransomware tactics.

Ransomware gangs are “recruiting”, not just hacking

The key shift is simple: criminals are reducing technical risk by increasing human manipulation. A vulnerability can be patched tomorrow. A relationship can be exploited today.

NCC’s analysis highlights how structured RaaS operations now think like businesses: recruitment funnels, commissions, performance incentives, and improved operational security. When attackers can persuade (or pressure) someone inside your organisation—or inside a supplier—to share credentials or approve access, they can bypass layers of security controls that would otherwise stop them.

A notorious example described in reporting: the Medusa ransomware group attempted to recruit a high-profile journalist by offering a percentage of a future ransom payment in exchange for access. That tactic is crude—but the underlying approach is sophisticated: target people with access, apply incentives, and avoid noisy exploitation.

Why SMEs are prime targets in 2026

SMEs rarely see themselves as “worth it”. Attackers disagree.

Here’s what makes UK small businesses attractive:

• Fewer internal controls: less separation of duties, fewer approval steps.
• More shared accounts and “quick fixes”: practical, but dangerous.
• Heavier reliance on contractors: outsourced IT, marketing, bookkeeping, virtual assistants.
• Supply-chain value: attackers may use you to reach a bigger client.

If your firm touches customer data, payment workflows, invoices, or admin credentials, you’re valuable—either as a direct payday or as a stepping stone.

The real risk: trusted access and “legitimate” credentials

Modern ransomware incidents often start with access that looks normal: a real user, a real login, a familiar device, a plausible email thread. That’s why security teams talk so much about identity and access management—and why SME owners should too.

Attackers specifically target:

• Email and Microsoft 365/Google Workspace accounts (password reuse, MFA fatigue, token theft)
• Remote access tools (RDP, VPNs, remote support apps)
• Finance processes (invoice approvals, bank detail changes)
• Admin consoles for SaaS tools (CRM, email marketing, e-commerce)

The operational logic for criminals is ruthless: if they can get valid access, they don’t need “elite hacking”. They can live off the land, blend in, and strike when it hurts most.

A February reality check: holidays, understaffing, and year-end patterns

NCC noted that end-of-year periods often see a surge because organisations are understaffed. Don’t assume this is only a December issue.

In the UK, early-year reality looks similar:

• Teams are still lean after Christmas.
• Finance teams are deep in year-end and tax workflows.
• Many businesses are pushing new growth initiatives (including new AI tools) without tightening access.

Attackers like moments when you’re busy, distracted, and approving things quickly.

How AI helps UK SMEs spot ransomware early (without a SOC)

AI won’t “solve ransomware”. What it can do—when used properly—is reduce detection time and standardise good security habits in organisations that don’t have full-time security staff.

Think of AI as a force-multiplier for:

• spotting weird activity faster than a human can
• reducing human error in routine security tasks
• triaging alerts so you don’t ignore the one that matters

Practical AI-supported controls that punch above their weight

You don’t need to build models from scratch. Most SMEs will get value from AI features already embedded in mainstream tools.

1. AI-assisted phishing and business email compromise (BEC) detection

   • Many email security tools now use machine learning to flag unusual sender behaviour, lookalike domains, and suspicious language patterns.
   • For SMEs, this matters because phishing is still the most common “first step” toward credential theft.

2. Identity anomaly detection

   • Good identity providers can detect impossible travel, unusual device sign-ins, and risky session behaviour.
   • This is especially relevant to ransomware groups seeking “legitimate” access.

3. Endpoint behaviour monitoring

   • Ransomware encryption behaviour is distinctive: high-volume file changes, unusual process activity, mass renames.
   • AI-informed endpoint detection can isolate a machine quickly—often the difference between a bad day and a business-ending week.

1. AI for log analysis and prioritisation
   • SMEs often have logs but don’t look at them.
   • AI-driven alerting can highlight the few events that are actually urgent (new admin account created, MFA disabled, forwarding rules added in email, backup deletion attempts).

A useful rule: If your tooling can’t tell you when a new admin user is created, you’re running blind.

Where AI makes things worse (if you’re careless)

AI tools can increase risk when you treat them as “plug-and-play” and forget governance.

Common SME mistakes I keep seeing:

• Sharing one AI tool login across the whole team
• Connecting AI assistants to inboxes, drives, CRMs with overly broad permissions
• Letting ex-staff keep access “just in case”
• Using AI to summarise emails—then trusting the summary without verifying a payment change

Attackers don’t need your AI system to be “hacked”. They just need it connected to the wrong place with the wrong permissions.

Build a human-risk firewall: the SME insider-threat playbook

When ransomware gangs court insiders—employees, contractors, or partners—the defence isn’t paranoia. It’s clear controls and predictable processes.

Start with access governance that fits a small team

The goal is to make “wrong things” hard, without slowing the business to a crawl.

Implement these baseline controls:

• MFA everywhere, prioritising email, finance, and admin consoles
• No shared admin accounts (create named accounts, even for contractors)
• Least privilege by default (marketing tools shouldn’t need finance exports)
• Two-person approval for:
  • bank detail changes
  • large payments
  • adding new admin users
  • changing backup settings

If that sounds heavy, pick two. In most SMEs, two-person approval for bank changes and named accounts for admins remove a huge chunk of risk.

Offboarding is where small firms get hurt

NCC specifically calls out the need for robust offboarding. This is where SMEs often fail because it’s awkward socially.

A tight offboarding checklist:

1. Disable accounts immediately (email, SaaS, VPN, password manager)
2. Rotate shared secrets (Wi‑Fi passwords, admin credentials, API keys)
3. Remove MFA devices from accounts
4. Transfer ownership of:
   • domains
   • ad accounts
   • analytics
   • code repositories
5. Audit forwarding rules and mailbox delegates

A blunt stance: “We’ll remove access next week” is an open invitation to trouble.

Train for recruitment attempts, not just phishing

Security awareness in 2026 should include scenarios like:

• “Someone offered me money for access”
• “A contractor asked for admin ‘temporarily’”
• “A partner wants a copy of the customer list for ‘analysis’”

Make reporting easy and consequence-free. If people fear getting blamed, they’ll hide near-misses—and you’ll only hear about it after encryption starts.

Ransomware resilience is part of UK national resilience

NCC’s telemetry also shows how industrial sectors and IT firms are frequently targeted, and how ransomware groups scale. That scaling doesn’t stop at borders.

From a National Security & Defence perspective, the uncomfortable truth is that SMEs are part of the national attack surface:

• small IT providers manage hundreds of endpoints across clients
• marketing agencies hold customer data and admin access to web platforms
• accountants and payroll bureaus sit next to payment rails
• logistics and suppliers connect into larger organisations’ systems

When enough small organisations are compromised, the aggregate impact becomes societal: delayed services, disrupted supply chains, and increased costs everywhere.

The SME ransomware checklist (do this in the next 14 days)

If you want a practical sprint that doesn’t require a security team, do this:

1. Backups: verify you can restore (not just that backups exist)
2. MFA: enable for email, finance tools, remote access, password manager
3. Admin audit: list every admin user across key systems and remove excess
4. Contractor access review: time-bound access with an end date
5. Email rules check: look for suspicious forwarding and mailbox delegates
6. Patch priority: browsers, endpoint OS, remote access tools
7. Incident plan: one page with who to call, what to shut off, and how to communicate

If you only do one thing: test restores. Ransomware negotiations are a terrible place to discover your backup strategy was wishful thinking.

What to do next (and what to ask before you buy more tools)

Buying security tools without fixing access and process control is like installing a better lock while leaving the window open.

If you’re adopting AI tools for marketing, customer support, or admin automation, ask these questions before connecting anything:

• What data will this AI tool be able to access?
• Can I restrict it to specific folders/inboxes?
• Who has admin rights, and how is MFA enforced?
• Can I export audit logs and set alerts for risky actions?

Ransomware gangs are building “hearts and minds” strategies because it works. The counter-strategy is boring but effective: tighter identity control, cleaner offboarding, and AI-enabled monitoring that helps a small team notice trouble early.

Where do you think your business is most exposed right now—email, contractor access, or finance approvals—and what would it take to tighten that up this month?