Cyber Security

How to Share Files Safely Online?

Share Files Safely
Online

Digital file sharing is now part of everyday business. From sending contracts to clients and sharing reports with staff, to collaborating with suppliers and storing confidential records in the cloud, most organisations rely on online file transfer every day. While this has made work faster and more flexible, it has also created new cyber security risks.

A poorly protected file, an incorrect sharing setting, a weak password, or a rushed email attachment can expose sensitive business data. This may include financial records, client details, employee information, project documents, passwords, intellectual property, or legal files. For small and medium businesses, even one data breach can lead to financial loss, reputational damage, downtime, legal issues, and loss of customer trust.

So, how can your business share files safely online?

The answer is not simply to stop sharing files. Modern businesses need fast, convenient collaboration. The real solution is to use secure file sharing practices, trusted platforms, strong access controls, staff training, and clear internal policies. With the right approach, your team can share files efficiently while reducing the risk of cyber attacks, accidental data leaks, and unauthorised access.

This guide from our cyber security specialists in Perth explains the safest ways to share files online and how your business can protect sensitive data.

Why Secure File Sharing Matters

Improve-Branding-Strategies-pages-computing-Computing Australia Group

Many businesses assume that file sharing is safe as long as the file reaches the intended person. Unfortunately, that is not always true. A file can be exposed at several points: when it is uploaded, stored, sent, downloaded, forwarded, or opened on an unsecured device.

Common risks include:

Sending files to the wrong recipient
Sharing public links without restrictions
Using weak or reused passwords
Allowing former employees to retain access
Sending confidential files through unsecured email
Storing sensitive documents on personal devices
Using public WiFi without protection
Falling for phishing links that lead to fake file-sharing pages
Failing to remove access after a project ends
Not encrypting files that contain sensitive information

Cyber criminals often target file-sharing systems because they know businesses store valuable data there. They may use phishing emails, stolen passwords, malware, fake login pages, or compromised accounts to gain access. Once inside, attackers may steal files, lock data with ransomware, or use the information for fraud.

Safe file sharing is therefore not just an IT issue. It is a business risk management issue.

Use Strong, Unique Passwords

Weak passwords remain one of the easiest ways for attackers to access business accounts. If your staff use simple passwords such as business names, birthdays, common words, or reused passwords across multiple services, your company data is at risk.

Every account used for file sharing should have a strong, unique password. This includes cloud storage platforms, email accounts, project management tools, accounting software, CRM systems, and remote access tools.

A strong password should be long, difficult to guess, and unique to that account. Instead of relying on short passwords with predictable substitutions, businesses should encourage the use of passphrases. A passphrase is a longer combination of unrelated words that is easier for humans to remember but harder for attackers to crack.

For example, a passphrase using several random words is usually stronger than a short password with a few symbols added.

Your business should also avoid sharing passwords between team members. Shared passwords make it difficult to track who accessed a file, who changed a setting, or who downloaded a document. Each staff member should have their own account with the correct level of access.

A password manager can help staff create and store strong passwords securely. This reduces the temptation to reuse passwords or save them in unsafe places such as spreadsheets, notebooks, browsers, or sticky notes.

Enable Multi-Factor Authentication

Multi-factor authentication, often called MFA or 2FA, adds an extra layer of protection to your accounts. Instead of relying only on a password, MFA requires another form of verification, such as an authenticator app, security key, biometric approval, or one-time code.

This is especially important for file-sharing services. If a cyber criminal steals a password through phishing or a data breach, MFA can help prevent them from logging in.

MFA should be enabled on:

Cloud storage platforms
Email accounts
Microsoft 365 and Google Workspace
Dropbox, OneDrive, SharePoint, and Google Drive
Remote access tools
Admin accounts
Password managers
Financial and accounting systems
Any platform that stores sensitive business files

Where possible, use stronger MFA methods such as authenticator apps, passkeys, or hardware security keys rather than SMS codes. SMS-based authentication is better than having no MFA, but it can be more vulnerable to SIM swapping and social engineering attacks.

Businesses should also train staff not to approve unexpected login prompts. If an employee receives an MFA request they did not initiate, they should reject it immediately and report it to IT support.

Avoid Sending Sensitive Files by Email

Email is convenient, but it is not always the safest way to share confidential files. Once an email attachment is sent, you lose much of your control over it. The recipient may forward it, download it to an unsecured device, or store it in an inbox indefinitely.

Email attachments can also create multiple copies of the same file across different systems, including the sender’s outbox, mail servers, recipient inboxes, backups, and downloaded folders. The more copies that exist, the harder it becomes to manage and protect the file.

For sensitive information, it is usually safer to share a secure link through a trusted file-sharing platform rather than sending the actual file as an attachment. A secure link allows you to control access, set expiry dates, require authentication, restrict downloads, and remove access later.

This is especially important for files containing:

Client records
Employee documents
Financial reports
Legal contracts
Medical or personal information
Passwords or credentials
Business plans
Intellectual property
Tax records
Confidential proposals

If email must be used, consider encrypting the file, password-protecting the document, and sending the password through a separate communication channel. However, this should not replace a properly managed secure file-sharing system.

Use Trusted Secure File-Sharing Platforms

Not all file-sharing tools offer the same level of security. Businesses should use reputable platforms that provide strong access controls, encryption, audit logs, admin settings, and account management features.

Common secure file-sharing options include:

Microsoft OneDrive
Microsoft SharePoint
Google Drive
Dropbox Business
Box
Citrix ShareFile
Egnyte
Secure client portals
Managed document management systems

The best option depends on your business size, industry, compliance requirements, and existing technology setup. For example, a business already using Microsoft 365 may benefit from OneDrive and SharePoint because they integrate well with Outlook, Teams, and Office applications.

When choosing a file-sharing platform, look for features such as:

Encryption in transit and at rest
User access controls
Admin management
MFA support
File activity logs
Link expiry settings
Download restrictions
Version history
Data loss prevention features
Secure external sharing controls
Ability to revoke access
Integration with your identity management system

Avoid using free consumer file-sharing tools for sensitive business data unless they have been reviewed and approved by your IT provider. Free tools may not provide the management, visibility, or compliance features your business needs.

Set the Right Permissions

One of the most common file-sharing mistakes is giving users more access than they need. This increases the risk of accidental changes, unauthorised downloads, and data exposure.

Businesses should follow the principle of least privilege. This means users should only have the minimum level of access required to complete their work.

For example:

A client may only need view access to a proposal
A contractor may only need access to one project folder
A staff member may need edit access to a team document but not the full company drive
A supplier may need temporary access that expires after the project ends

Avoid using “anyone with the link” sharing for sensitive files. This setting can be risky because the link may be forwarded, copied, or discovered by someone who should not have access.

Instead, use restricted sharing wherever possible. Require users to sign in before accessing files, and only share documents with specific email addresses or approved groups.

You should also review file permissions regularly. Staff roles change, employees leave, contractors finish projects, and clients no longer need access. Without regular reviews, old permissions can become a serious security gap.

Add Expiry Dates to Shared Links

Many file-sharing platforms allow you to set expiry dates on shared links. This is a simple but powerful way to reduce long-term exposure.

For example, if you are sharing a proposal with a client for review, the link may only need to remain active for two weeks. If you are sharing files with a contractor, access may only be needed until the project is complete.

Setting expiry dates helps ensure that sensitive files are not available forever. It also reduces the chance of old links being reused, forwarded, or accessed after they are no longer required.

Your business should create a policy for link expiry based on the type of information being shared. Highly confidential documents should have shorter expiry periods and stricter access controls.

Use Encryption for Sensitive Data

Encryption helps protect data by making it unreadable to unauthorised users. Secure file-sharing platforms usually encrypt data while it is being transferred and while it is stored. However, for highly sensitive files, additional encryption may be required.

Encryption is especially important when sharing:

Legal documents
Financial records
Medical information
Government documents
Identity documents
Confidential business plans
Intellectual property
HR files
Customer databases

Businesses should ensure that their file-sharing tools use secure protocols and encryption standards. Staff should also avoid sending unencrypted confidential documents through email or messaging apps.

For extremely sensitive files, your IT provider may recommend encrypted archives, secure client portals, or specialist document management systems.

Secure Your Network

File sharing is only as secure as the network used to access it. If staff share or download files over unsecured networks, attackers may be able to intercept data, steal credentials, or redirect users to malicious websites.

Employees should avoid using public WiFi for business file sharing, especially in cafes, airports, hotels, shopping centres, and shared workspaces. Public WiFi networks are often poorly secured and can be used by attackers to monitor traffic or trick users into connecting to fake hotspots.

If staff must work remotely, they should use a secure connection such as a trusted VPN, mobile hotspot, or managed remote access solution. Business devices should also have firewalls enabled and security software installed.

Office networks should be protected with strong WiFi passwords, secure router settings, network segmentation where appropriate, and regular firmware updates. Guest WiFi should be separated from internal business systems so visitors cannot access shared drives or company resources.

Train Employees to Recognise Phishing

Phishing remains one of the most common ways attackers gain access to business accounts. A cyber criminal may send an email that appears to come from Microsoft, Google, Dropbox, a bank, a supplier, or even a senior employee. The message may ask the recipient to open a file, click a link, enter a password, or approve a login request.

Once the employee enters their login details on a fake page, the attacker can access business files.

Cyber security training should teach employees to:

Check sender addresses carefully
Hover over links before clicking
Be cautious with unexpected attachments
Avoid entering passwords from email links
Report suspicious messages
Verify unusual file-sharing requests
Be alert to urgent or threatening language
Confirm payment or document requests through another channel
Avoid approving unexpected MFA prompts

Training should not be a one-time activity. Cyber threats change constantly, so staff awareness should be refreshed regularly. Short, practical training sessions, phishing simulations, and clear reporting procedures can significantly reduce risk.Weak passwords remain one of the easiest ways for

Be Careful with Remote Work and BYOD

Remote work and Bring Your Own Device policies can make file sharing more flexible, but they also create additional risks.

When staff use personal laptops, tablets, or phones for work, the business may have less control over device security. Personal devices may not have updated antivirus software, secure passwords, full-disk encryption, or remote wipe capability. They may also be shared with family members or connected to unsafe networks.

If your business allows BYOD, you should have a clear policy covering:

Approved devices
Minimum security requirements
Screen locks and passwords
Software updates
Antivirus protection
Device encryption
Lost or stolen device reporting
Use of company-approved apps
Restrictions on downloading files locally
Removal of company data when employment ends

Where possible, businesses should use managed devices for handling confidential information. If personal devices are allowed, mobile device management or endpoint management tools can help enforce security settings.

Remote workers should also be reminded not to download sensitive files to personal desktops, USB drives, or unmanaged cloud storage accounts.

Keep Software and Devices Updated

Outdated software can contain security vulnerabilities that attackers know how to exploit. This includes operating systems, browsers, office applications, file-sharing apps, PDF readers, antivirus tools, routers, and mobile devices.

Businesses should apply updates promptly, especially security updates. Delaying updates can leave systems exposed to known threats.

A strong patching process should include:

Automatic updates where appropriate
Regular checks for failed updates
Updates for third-party applications
Firmware updates for network devices
Browser and extension updates
Mobile device updates
Removal of unsupported software

Staff should be trained not to ignore update prompts indefinitely. However, updates should also be managed carefully to avoid disruption. Your IT provider can help create a patch management process that balances security and business continuity.

Use Antivirus, Endpoint Protection, and Firewalls

Antivirus and endpoint protection tools help detect malware, ransomware, spyware, and other threats that may compromise files or steal credentials. Modern endpoint protection can also identify suspicious behaviour, block malicious downloads, and alert administrators to potential incidents.

Firewalls help control network traffic and reduce the chance of unauthorised access. Both device-based firewalls and network firewalls play an important role in business security.

Your business should ensure that:

Antivirus or endpoint protection is installed on all business devices
Security tools are updated automatically
Firewalls are enabled and correctly configured
Alerts are monitored
Suspicious activity is investigated
Unused services and ports are disabled
Staff cannot easily bypass security controls

Security tools are not a complete solution on their own, but they are an important layer of protection.

Back Up Important Files

Secure file sharing should always be supported by reliable backups. If files are accidentally deleted, overwritten, corrupted, or encrypted by ransomware, backups may be the only way to recover quickly.

Many businesses assume that cloud storage automatically replaces backups. This is a dangerous assumption. Cloud platforms may provide version history and retention features, but they may not protect you from every scenario.

Your backup strategy should include:

Regular backups of critical business data
Backups stored separately from the main system
Protection against ransomware
Version history
Access controls for backup systems
Regular restore testing
Clear recovery procedures
Backup monitoring and alerts

Testing is especially important. A backup is only useful if it can be restored when needed.

Create a File Sharing Policy

A clear file-sharing policy helps staff understand what is acceptable and what is not. Without a policy, employees may use whatever method feels quickest, even if it is unsafe.

Your policy should explain:

Which file-sharing platforms are approved
What types of data can be shared externally
Who can approve external sharing
When encryption is required
How long links should remain active
Whether downloads are allowed
How to share files with clients and suppliers
What to do if a file is sent to the wrong person
How to report suspicious activity
Rules for personal devices and remote work
Requirements for MFA and strong passwords

The policy should be easy to understand and practical for daily work. If secure processes are too complicated, staff may look for shortcuts. The goal is to make safe file sharing simple and consistent.

Monitor File Activity

Many secure file-sharing platforms provide activity logs. These logs can show who accessed a file, when it was downloaded, whether it was shared externally, and whether permissions were changed.

Monitoring file activity can help detect unusual behaviour, such as:

A user downloading large numbers of files
Access from unfamiliar locations
External sharing of confidential folders
Repeated failed login attempts
Access outside normal business hours
Former staff accounts still active
Unexpected permission changes

Businesses should review activity logs regularly, especially for sensitive folders. Larger organisations may benefit from security monitoring tools that alert IT teams when suspicious behaviour occurs.

Remove Access When It Is No Longer Needed

Access management is one of the most important parts of secure file sharing. When employees leave, contractors finish work, or clients complete a project, their access should be removed promptly.

Your offboarding process should include:

Disabling user accounts
Revoking file-sharing access
Removing access to cloud platforms
Changing shared passwords where necessary
Recovering company devices
Transferring ownership of files
Reviewing external sharing links
Removing access from groups and shared drives

Do not rely on memory or informal processes. Use an offboarding checklist to ensure access is removed every time.

Be Careful When Sharing with External Users

Sharing files outside your organisation is often necessary, but it should be handled carefully. External users may have different security standards, and you may not control their devices or networks.

Before sharing files externally, ask:

Does this person genuinely need access?
Should they view, comment, or edit?
Should downloads be blocked?
Should the link expire?
Should the file be watermarked?
Is the information confidential?
Is approval required before sharing?
Can the file be shared through a secure portal instead?

External sharing should be limited, tracked, and reviewed. Sensitive files should not be shared using public links or personal email addresses unless there is a clear business reason and proper protection.

Avoid USB Drives Where Possible

USB drives may seem convenient, but they can create serious security risks. They are easy to lose, difficult to track, and can spread malware between devices. If a USB drive contains confidential files and is misplaced, your business may face a data breach.

Where possible, use secure cloud-based sharing instead of removable media. If USB drives must be used, they should be encrypted, password-protected, approved by the business, and scanned for malware.

Staff should also be warned never to plug unknown USB devices into business computers.

What to Do If a File Is Shared Incorrectly

Mistakes happen. A staff member may send a file to the wrong person, create a public link by accident, or share a folder with too many users. The key is to respond quickly.

If a file is shared incorrectly:

1. Revoke access immediately.
2. Change the link or delete it.
3. Check whether the file was downloaded.
4. Notify your IT provider or security team.
5. Record what happened.
6. Assess whether the incident must be reported.
7. Inform affected parties where required.
8. Review the process to prevent it happening again.

Staff should feel comfortable reporting mistakes quickly. If employees fear blame, they may delay reporting, which can make the problem worse.

Safe File Sharing Checklist for Businesses

Use this checklist to improve your organisation’s file-sharing security:

Use approved business-grade file-sharing platforms
Enable MFA on all important accounts
Use strong, unique passwords
Avoid sending sensitive files as email attachments
Set link expiry dates
Restrict access to specific users
Avoid public “anyone with the link” sharing
Review permissions regularly
Remove access for former staff and contractors
Train employees to detect phishing
Keep devices and software updated
Use antivirus, endpoint protection, and firewalls
Back up critical files
Secure remote work and BYOD devices
Monitor file access logs
Create a clear file-sharing policy
Encrypt highly sensitive files
Report and respond quickly to mistakes

Final Thoughts

Sharing files online is essential for modern business, but it must be done securely. A single careless link, weak password, or unsecured device can expose sensitive information and create serious consequences.

The good news is that secure file sharing does not need to be complicated. By using trusted platforms, enabling multi-factor authentication, setting proper permissions, training staff, keeping systems updated, and reviewing access regularly, your business can reduce risk while still working efficiently.

Cyber security is strongest when people, processes, and technology work together. If your business shares files with staff, clients, suppliers, or contractors, now is the time to review your systems and close any security gaps.

Need help securing your business file sharing? Contact the cyber security specialists at Computing Australia Group or email cybersecurity@computingaustralia.group. Our Perth-based team can help you assess your current setup, improve cloud security, protect sensitive files, and keep your business safe from cyber threats.

Jargon Buster

Password Manager – Software to create, store and manage passwords in an encrypted form.

BYOD – Bring Your Own Device – a policy where staff can use their own devices at work with specific regulations to follow.

VPN – Virtual Private Network – an encrypted connection across a public network that provides online anonymity.

2FA – Two-factor authentication – is a security system that needs two distinct authentication factors to verify your identity to access an account or information.

David Brown

Let's Talk

Share Files Safely Online