Law Firms & Cyber Security: How to Stay Protected

Law firms hold some of the most confidential and commercially sensitive information belonging to individuals and businesses.

Client files may include financial records, property transactions, personal correspondence, medical information, employment disputes, litigation strategies and identity documents. Many firms also handle significant amounts of client money.

This combination of valuable information, urgent transactions and trusted communications makes the legal sector an attractive target for cybercriminals. The National Cyber Security Centre warns that law practices of every size and specialism face cyber threats, while the Solicitors Regulation Authority continues to identify phishing, email modification, ransomware and third-party compromise as significant risks.

A successful attack could interrupt live matters, expose privileged or confidential information, redirect client money and leave employees unable to access essential systems.

Cybersecurity therefore needs to be treated as a business, regulatory and client-care responsibility rather than simply an IT issue.

Key Threats & How to Respond to Them

Understanding how law firms are targeted is the first step towards building effective protection.

The following threats are among the most important risks facing legal practices.

1. Phishing Emails

Phishing emails are designed to persuade employees to reveal passwords, open malicious attachments or visit fraudulent websites.

An attacker may impersonate:

• Microsoft
• A client
• Counsel
• A court
• A bank
• A property agent
• A senior partner
• An IT provider
• A known supplier

Legal work often involves urgent messages, unfamiliar contacts and large numbers of attachments. This can make it harder for employees to distinguish a genuine communication from a convincing attack.

The SRA has previously reported that email was involved in more than four out of five cybercrime incidents reported to it, demonstrating why email security remains particularly important for law firms.

How Should Law Firms Respond?

Firms should combine employee awareness with technical email protection.

This should include:

• Regular phishing-awareness training
• Email filtering
• Attachment scanning
• Protection against malicious links
• Multi-factor authentication
• A simple method for reporting suspicious messages
• Clear verification procedures for unusual requests

Employees should never be criticised for reporting a suspicious email, even when it later proves to be genuine.

Early reporting may allow the IT team to block a malicious website, reset an exposed password or remove the same email from other mailboxes before anyone else responds.

2. Email Modification and Payment-Diversion Fraud

Email modification fraud is particularly dangerous for law firms handling property transactions, settlements and client money.

An attacker may gain access to a solicitor’s or client’s email account and monitor a conversation until money is about to be transferred.

The criminal may then send altered bank details while impersonating one of the genuine parties.

In some cases, messages may be deleted or replaced to prevent the solicitor and client from realising they are communicating with a fraudster.

SRA case studies show how intercepted solicitor-client communications and modified invoices have resulted in funds being transferred to criminal-controlled accounts.

How Should Law Firms Respond?

Bank details and changes to payment instructions should always be verified through an independent and trusted communication method.

This could include calling a previously verified telephone number rather than using the contact details contained in the suspicious email.

Firms should also:

• Warn clients that bank details will not change without formal verification
• Avoid sending complete payment instructions through unsecured email
• Introduce dual approval for significant transfers
• Monitor accounts for unusual forwarding rules
• Use multi-factor authentication
• Protect Microsoft 365 with Conditional Access
• Configure SPF, DKIM and DMARC for business domains
• Establish an urgent payment-fraud response process

Employees should feel authorised to question unusual instructions, regardless of how senior or important the apparent sender may be.

Urgency should increase verification rather than reduce it.

3. Ransomware

Ransomware can encrypt files, disable systems and prevent employees from accessing active matters.

Modern ransomware attacks may also involve data theft.

Criminals may copy confidential information before encrypting the firm’s systems and then threaten to publish it unless money is paid.

The consequences may include:

• Loss of access to case-management systems
• Interrupted court or completion deadlines
• Exposure of confidential information
• Business closure
• Regulatory investigation
• Recovery costs
• Client complaints
• Reputational damage

The NCSC provides specific guidance to help organisations prevent, respond to and recover from ransomware and other forms of malware.

How Should Law Firms Respond?

Protection should include several separate layers:

• Managed endpoint detection and response
• Security patching
• Restricted administrator privileges
• Email and web filtering
• Secure remote access
• Network segmentation
• Application control
• Monitored backups
• Employee awareness training
• An incident-response plan

Backups should be separated from the live environment and protected so an attacker cannot easily delete or encrypt them.

They must also be tested.

A notification confirming that a backup completed does not prove that the firm can restore its systems within the time required to protect clients and meet legal deadlines.

4. Compromised Microsoft 365 Accounts

Microsoft 365 may contain a law firm’s email, calendars, files, Teams conversations, SharePoint sites and user identities.

A compromised account could allow an attacker to:

• Read confidential emails
• Download client documents
• Impersonate a solicitor
• Reset other passwords
• Create malicious forwarding rules
• Send phishing emails
• Monitor transactions
• Access shared files
• Target clients and suppliers

A password alone is not sufficient protection for a legal organisation’s cloud environment.

How Should Law Firms Respond?

Multi-factor authentication should be enabled for every user, with stronger controls applied to administrators and employees handling sensitive information.

Firms should also consider:

• Conditional Access
• Blocking outdated authentication methods
• Restricting sign-ins from unmanaged devices
• Monitoring unusual login locations
• Separate administrator accounts
• Reviewing active sessions
• Disabling unused accounts
• Alerting on new forwarding rules
• Reviewing third-party application permissions
• Protecting privileged accounts with additional controls

Unexpected authentication requests should be treated as possible signs that someone already knows the user’s password.

Employees should reject and report any prompt they did not initiate.

5. Weak, Shared or Reused Passwords

Law firms may use many separate platforms, including case-management software, legal research tools, accounting applications, portals and cloud services.

Employees may respond by reusing passwords or storing them in documents, browsers or handwritten notes.

Shared logins create additional problems because the firm may be unable to determine who accessed or changed information.

When an employee leaves, a shared password may also remain known to them unless it is changed everywhere.

How Should Law Firms Respond?

Every user should have an individual account and a unique password.

A managed business password manager can help employees generate, store and share credentials securely.

Firms should also:

• Remove shared accounts where possible
• Enable multi-factor authentication
• Review password-manager access
• Disable leaver accounts promptly
• Avoid sending passwords through email
• Monitor whether business credentials appear in known breaches
• Use separate accounts for administration
• Review service accounts and API credentials

Passwords should form one part of the firm’s security rather than the only barrier protecting sensitive systems.

6. Outdated Software and Unpatched Devices

Cybercriminals search for known vulnerabilities in computers, servers, applications, firewalls and remote-access systems.

A law firm may believe it is secure because antivirus software is installed, while an unsupported server or unpatched application remains exposed.

Commonly overlooked systems include:

• Case-management applications
• Document-management software
• Remote-access tools
• Firewalls
• Servers
• Web browsers
• PDF software
• Dictation platforms
• Printers and scanners
• Home-working devices

Older technology may continue operating normally while no longer receiving security updates.

How Should Law Firms Respond?

A managed patching process should identify, approve, deploy and monitor updates across the firm.

The process should cover operating systems and supported third-party applications.

Law firms should maintain an accurate inventory showing:

• Devices
• Installed applications
• Software versions
• Support dates
• Owners
• Patch status
• Security status
• Warranty information

Critical vulnerabilities should be prioritised according to risk rather than waiting for the next routine maintenance window.

Unsupported software should be replaced, upgraded or isolated through a documented plan.

7. Remote and Hybrid Working

Solicitors may work from home, court, client locations, hotels and shared workspaces.

This flexibility can improve productivity, but it also expands the number of places from which confidential information is accessed.

Risks may include:

• Insecure Wi-Fi
• Shared family devices
• Lost laptops
• Visible screens
• Unmanaged personal equipment
• Local storage of client documents
• Weak home-network security
• Unapproved cloud applications

The SRA’s research has highlighted how remote working and dependence on digital services can increase firms’ exposure to cybersecurity risks.

How Should Law Firms Respond?

Remote access should be limited to authorised users and managed devices.

Suitable controls may include:

• Device encryption
• Cloud device management
• Secure screen locks
• Managed endpoint protection
• Multi-factor authentication
• Conditional Access
• Secure VPN access where required
• Automatic security updates
• Remote device wiping
• Restrictions on local data storage

Employees should also receive clear guidance about protecting conversations and documents when working in public.

A technical control cannot prevent someone nearby from reading a confidential document on an employee’s screen.

8. Third-Party and Supply-Chain Attacks

Law firms depend on external providers for services including:

• Case management
• Conveyancing searches
• Legal research
• Cloud hosting
• Microsoft 365
• Dictation
• Accounting
• Document signing
• IT support
• Barristers’ portals
• Outsourced administration

An attacker may target a supplier because compromising one provider could create access to several customer organisations.

A third-party incident may also make an essential application unavailable even when the law firm’s own systems have not been directly attacked.

Third-party compromise is one of the principal cyber risks identified by the SRA for the legal sector.

How Should Law Firms Respond?

Suppliers should be assessed before they receive access to systems or confidential information.

Due diligence should consider:

• Security certifications
• Multi-factor authentication
• Encryption
• Data locations
• Subcontractors
• Incident-reporting arrangements
• Backup and recovery
• Access controls
• Penetration testing
• Business continuity
• Contract termination
• Data deletion

The firm should maintain a supplier register showing which systems and information each provider can access.

Contracts should explain how quickly the supplier must report an incident and what support it will provide during an investigation.

9. Impersonation of Solicitors and Law Firms

Criminals may misuse the name, website, address or SRA details of a genuine solicitor or firm.

They may create a lookalike website or register an email domain that differs from the real firm’s address by only one character.

Current SRA scam alerts regularly document websites, emails and messages that misuse the identities of genuine solicitors and firms.

The purpose may be to:

• Redirect client money
• Obtain identity documents
• Demand fraudulent fees
• Steal cryptocurrency
• Obtain confidential information
• Make a scam appear legitimate

How Should Law Firms Respond?

Firms should monitor their domains and online identity.

Protective measures may include:

• DMARC enforcement
• SPF and DKIM
• Registration of important defensive domains
• Website monitoring
• Domain-expiry controls
• A clear client-verification process
• Prominent fraud warnings
• Monitoring SRA scam alerts
• A procedure for reporting impersonation

Clients should know how to verify the firm’s genuine telephone numbers, email addresses and payment instructions.

The firm should respond quickly when it becomes aware of a fraudulent website or message using its identity.

10. Accidental Data Loss

Not every security incident is caused by a cybercriminal.

Employees may accidentally:

• Email documents to the wrong recipient
• Share the wrong OneDrive link
• Grant access to an entire SharePoint site
• Leave papers in a public place
• Lose a laptop
• Upload files to an unapproved service
• Attach the wrong client document
• Delete important information
• Misconfigure external access

Accidental disclosure can still create serious consequences for clients and the firm.

How Should Law Firms Respond?

Technical controls should reduce the chance that a simple mistake becomes a major breach.

These may include:

• Data-loss prevention
• Sensitivity labels
• Email-recipient warnings
• External-sharing controls
• Device encryption
• Secure file-transfer services
• Retention policies
• Access reviews
• Restricted use of removable storage
• Secure printing

Employees should be trained to report mistakes immediately.

Early reporting may allow access to a shared link to be removed, an email to be recalled where possible or the unintended recipient to be contacted quickly.

11. Uncontrolled Use of Artificial Intelligence

AI tools can help solicitors summarise information, prepare initial drafts and search large document collections.

However, employees may enter client information into unapproved consumer AI services without understanding how it will be processed or retained.

AI-generated output may also contain inaccuracies, invented references or incorrect legal conclusions.

The SRA allows firms to use appropriate technology, including AI, but its use remains subject to existing professional standards and legal obligations.

How Should Law Firms Respond?

The firm should establish an AI policy covering:

• Approved tools
• Permitted information
• Prohibited data
• Human review
• Confidentiality
• Accuracy checks
• Copyright
• Record keeping
• Client communication
• Supplier approval

AI-generated material should not be assumed to be accurate because it is written confidently.

Solicitors remain responsible for the advice, documents and decisions produced under their supervision.

Protecting Client Money

Law firms handling client money require particularly strong controls.

A compromised email account or fraudulent payment instruction could lead to funds being transferred to the wrong account.

Suitable controls should include:

• Dual authorisation
• Independent verification
• Segregated duties
• Daily account monitoring
• Restricted payment permissions
• Alerts for unusual transactions
• Secure communication of bank details
• Clear escalation procedures
• Regular employee training

Employees should not be pressured into bypassing established payment procedures because a request appears urgent.

The SRA expects firms to understand their obligations regarding client money and to report relevant cyber incidents and losses, including successful attacks even where a loss has subsequently been reimbursed.

Protecting Client Confidentiality

Cybersecurity is closely connected to the professional responsibility to protect confidential client information.

Access should be based on role and business need.

Not every employee should automatically be able to access every matter.

Firms should regularly review:

• Matter access
• Shared mailboxes
• SharePoint permissions
• Microsoft Teams membership
• Guest accounts
• Former employee access
• Administrator privileges
• Third-party accounts
• External sharing links

Access should be removed when it is no longer required.

A secure platform cannot compensate for permissions that were granted too broadly.

Build a Strong Cybersecurity Culture

Technology cannot identify every fraudulent request or prevent every mistake.

Employees need the confidence to challenge unusual activity.

A strong cybersecurity culture should encourage people to:

• Pause before making payments
• Verify unexpected instructions
• Report suspicious messages
• Reject unexplained authentication prompts
• Protect confidential conversations
• Follow approved processes
• Report mistakes quickly
• Ask for help when uncertain

Senior partners and directors must follow the same procedures as everyone else.

Criminals commonly exploit authority by impersonating senior people and relying on employees being reluctant to question them.

Managers should make it clear that verification is expected, even when the apparent request comes from a partner or important client.

Use Multi-Factor Authentication Throughout the Firm

Multi-factor authentication should protect:

• Microsoft 365
• Remote access
• Case-management systems
• Accounting software
• Password managers
• Backup platforms
• Administrator accounts
• Cloud applications

Authentication apps and security keys are generally preferable to relying solely on text messages where stronger options are supported.

Legacy authentication methods that cannot enforce modern protections should be disabled.

Secure Every Device

All computers, laptops and supported mobile devices should be centrally managed.

This allows the firm or its IT provider to apply:

• Security policies
• Endpoint protection
• Encryption
• Software updates
• Screen-lock settings
• Application restrictions
• Web filtering
• Compliance checks

Employees should not normally have unrestricted local-administrator access.

Removing unnecessary administrator privileges can limit the changes malicious software is able to make.

Maintain Reliable and Tested Backups

A suitable backup strategy should cover the information and systems needed to operate the practice.

This may include:

• Servers
• Case-management data
• Microsoft 365
• SharePoint
• OneDrive
• Email
• Accounting systems
• Document-management platforms

The firm should understand:

• What is backed up
• How often it is protected
• Where copies are stored
• Who can delete them
• How long they are retained
• How quickly information can be restored
• When recovery was last tested

At least one copy should be isolated or otherwise protected from an attacker who compromises the main network.

Prepare an Incident-Response Plan

A cyber incident is the wrong time to decide who is responsible.

The firm’s plan should explain:

• Who receives security alerts
• Who contacts the IT provider
• How affected devices are isolated
• Who secures compromised accounts
• Who preserves evidence
• Who assesses regulatory reporting
• Who communicates with clients
• Who contacts the insurer
• Who makes urgent business decisions
• How systems will be recovered

Contact information should remain available when email and normal business systems cannot be used.

The plan should be tested through practical exercises involving senior management, compliance, IT and relevant department heads.

Reporting a Cyber Incident

Reporting obligations will depend on what has happened.

A personal data breach that creates a relevant risk may need to be reported to the Information Commissioner’s Office without undue delay and within 72 hours of the firm becoming aware of it. Firms should begin recording and assessing the incident immediately, even where it is not yet clear whether notification will be required.

The SRA states that it expects firms to report promptly when the firm or its clients are directly affected by a cyberattack. A serious breach of the Standards and Regulations may also create an obligation under rule 3.9 of the Code of Conduct for Firms.

Depending on the incident, the firm may also need to contact:

• Its cyber insurer
• Law enforcement
• Its bank
• Affected clients
• Other regulators
• Relevant suppliers

Reporting decisions should be documented, including the reasons why an incident was or was not notified.

Consider Cyber Essentials

Cyber Essentials is a government-backed scheme intended to help organisations defend themselves against common internet-based attacks.

Its five principal areas are:

• Firewalls
• Secure configuration
• Security update management
• User access control
• Malware protection

Certification does not guarantee that a law firm will never experience an attack.

However, it can provide a practical baseline and demonstrate that essential controls have been reviewed.

Cyber Essentials Plus includes an independent technical assessment and may provide additional assurance to clients and insurers.

Review Cybersecurity Regularly

Cybersecurity should not be treated as a one-time project.

A review should be completed when:

• A new office opens
• The firm changes IT provider
• Employees begin remote working
• A new case-management system is introduced
• A merger takes place
• A new supplier receives access
• AI tools are introduced
• An incident occurs
• Important regulations or client requirements change

Regular reviews should cover:

• Accounts
• Permissions
• Devices
• Software
• Backups
• Suppliers
• Security alerts
• Policies
• Training
• Incident response
• Business continuity

The findings should be recorded and converted into a prioritised improvement plan.

Cybersecurity Is a Leadership Responsibility

Partners and directors do not need to become technical specialists.

They do need to understand:

• Which systems are critical
• What information the firm holds
• Who can access it
• What the principal risks are
• Whether backups are tested
• Whether security alerts are monitored
• How the firm will respond to an incident
• Which suppliers create dependencies
• Whether employees receive suitable training

The NCSC’s board guidance treats cyber risk as a leadership and business-resilience responsibility because incidents can create operational, financial, reputational and legal consequences.

Cybersecurity should therefore be discussed alongside financial, regulatory and operational risks.

How Hamilton Group Can Help

Hamilton Group helps law firms protect their systems, client information and employees through managed IT support and cybersecurity services.

We can help with:

• Microsoft 365 security reviews
• Multi-factor authentication
• Conditional Access
• Managed endpoint protection
• Security patching
• Email security
• DMARC, SPF and DKIM
• Cloud backups
• Backup monitoring and recovery testing
• SharePoint and OneDrive permissions
• Firewall and network security
• Secure remote working
• Cybersecurity awareness training
• Cyber Essentials support
• Supplier risk reviews
• Incident-response planning
• Business continuity
• Managed IT support

At Hamilton Group, we aim to make first contact on IT support requests within 15 minutes, helping legal professionals receive assistance quickly when a technical or security issue affects their work.

We can review your current protection, identify potential gaps and create a practical improvement plan suited to the size, work and regulatory responsibilities of your firm.

Call Hamilton Group today on 0330 043 0069 to discuss how we can help protect your law firm, client information and critical legal services from cyber threats.

This article provides general information and should not be treated as legal, regulatory or data-protection advice. Firms should obtain appropriate professional guidance relating to their specific obligations.