Cloud storage allows users to access documents, photographs, backups, and work files from different devices and locations.
Services such as online drives and collaboration platforms make it easy to share information with coworkers, customers, friends, and family.
However, incorrect sharing settings, weak account security, or careless links can expose private and business information.
A file stored in the cloud is not automatically public, but it is also not automatically secure. Protection depends on account settings, access permissions, and how the file is shared.
Common cloud-storage risks
Cloud data may be exposed through:
- Weak or reused passwords.
- Compromised email accounts.
- Public sharing links.
- Incorrect folder permissions.
- Lost or stolen devices.
- Phishing attacks.
- Unknown connected applications.
- Former employees retaining access.
- Unprotected backup copies.
- Accidental sharing with the wrong person.
Many cloud incidents happen because of configuration mistakes rather than a direct attack on the provider.
Understand sharing options
Cloud services may offer several sharing choices.
Private
Only the account owner can access the file.
This is the safest default for personal and confidential information.
Specific people
The owner selects the users or email addresses that may access the file.
This is preferable for business documents and sensitive information.
Anyone with the link
Anyone who obtains the link may be able to open the file.
The link may be forwarded, copied, published, or discovered later.
This setting should not be treated as private.
Public
The content may be available to anyone and may appear in search results.
Public access should be used only when the information is intended for the public.
Use the least access necessary
When sharing a file, decide what the recipient actually needs.
Possible permissions include:
- View.
- Comment.
- Edit.
- Download.
- Reshare.
- Manage access.
Someone who only needs to read a document should not receive permission to edit or share it with others.
Business administrators should avoid giving full-control permissions when view-only access is sufficient.
Avoid permanent public links
Public or unrestricted links are easy to create and easy to forget.
Over time, the file may remain available even after the original reason for sharing has ended.
When possible:
- Share with named accounts.
- Require sign-in.
- Set an expiration date.
- Use a password when supported.
- Disable downloads where appropriate.
- Remove access after completion.
- Review old links regularly.
A temporary project link should not remain active forever.
Check the recipient carefully
Before sharing, confirm:
- The email address is correct.
- The recipient is the intended person.
- The recipient still works with the organization.
- The selected permission is appropriate.
- The correct file or folder was chosen.
- The folder does not contain additional sensitive files.
A typing error in an email address may share information with the wrong person.
Be especially careful when two contacts have similar names.
Folder sharing can expose more than one file
Sharing a folder may provide access to every file already inside it and files added later.
Before sharing a folder:
- Review all existing contents.
- Remove unrelated documents.
- Check inherited permissions.
- Confirm who can add new members.
- Decide whether editing is necessary.
- Review subfolders.
Creating a separate folder for external sharing is often safer than sharing an internal working folder.
Protect your cloud account
The cloud account should use:
- A strong and unique password.
- Multi-Factor Authentication.
- Updated recovery information.
- Login alerts.
- Regular session reviews.
- Secure backup codes.
The password should not be reused on other services.
The connected email account must also be protected because it may be used to reset the cloud-storage password.
Review active sessions and devices
Cloud platforms may show:
- Signed-in devices.
- Recent activity.
- Login locations.
- Connected applications.
- Browser sessions.
Remove unknown or unused devices.
If suspicious activity appears:
- Change the password.
- Sign out other sessions.
- Review MFA.
- Check recovery information.
- Review recent sharing changes.
- Inspect deleted or modified files.
Be careful with shared-document phishing
Attackers may send fake invitations claiming that someone shared:
- An invoice.
- A confidential document.
- A salary file.
- A voice message.
- A contract.
- A scanned document.
- A cloud folder.
The link may open a fake login page.
Before signing in:
- Check the sender.
- Verify whether the document was expected.
- Inspect the domain.
- Open the cloud service directly.
- Check the shared-items section inside your real account.
Do not trust a page only because it uses the logo of a familiar cloud provider.
Connected applications
Third-party applications may request access to cloud files.
Examples include:
- PDF editors.
- Backup tools.
- Document converters.
- Project-management systems.
- Automation platforms.
- AI tools.
- File-sharing utilities.
Before approving access, check:
- Which files the application can read.
- Whether it can modify or delete files.
- Whether it needs access to the entire drive.
- Whether the developer is trustworthy.
- Whether the connection can be limited.
Remove access for applications you no longer use.
Protect sensitive documents
Sensitive files may include:
- Identity documents.
- Contracts.
- Employee records.
- Customer information.
- Financial statements.
- Banking details.
- Password exports.
- Business plans.
- Legal documents.
- Medical records.
These files should use stronger protection.
Consider:
- Encryption.
- Restricted access.
- Named recipients.
- Expiring links.
- Download restrictions.
- Activity monitoring.
- Separate secure folders.
Do not place highly sensitive files in an unrestricted shared folder.
Do not share passwords through cloud files
A shared spreadsheet or document containing passwords creates serious risk.
Use a trusted password manager instead.
Avoid storing:
- Passwords.
- MFA backup codes.
- API keys.
- Private encryption keys.
- Administrator credentials.
in ordinary cloud documents or unprotected notes.
Cloud storage is not always a complete backup
Cloud synchronization and backup are not always the same.
If a file is deleted, corrupted, or encrypted by ransomware, synchronization may copy the same change to the cloud.
A strong backup plan may include:
- Version history.
- Recycle-bin retention.
- A separate backup service.
- Offline backup copies.
- Regular restore testing.
Important files should not depend on one account or one storage location.
Business access control
Businesses should assign access based on job responsibilities.
Employees should only access the files required for their work.
Organizations should:
- Use company-managed accounts.
- Avoid personal cloud accounts.
- Use individual user identities.
- Review permissions regularly.
- Remove former employees promptly.
- Limit external sharing.
- Monitor sensitive folders.
- Define retention policies.
- Protect administrator accounts.
- Maintain backups.
Shared usernames make it difficult to identify who accessed or changed a document.
Employee offboarding
When an employee or contractor leaves, the organization should:
- Disable their account.
- Remove active sessions.
- Transfer ownership of important files.
- Remove shared links.
- Review external access.
- Reset shared credentials.
- Preserve required business data.
- Review connected applications.
Delaying account removal may leave business information exposed.
Version history and recovery
Many cloud platforms keep previous versions of documents.
Version history can help recover from:
- Accidental edits.
- Deleted content.
- Malicious changes.
- Ransomware encryption.
- Incorrect document updates.
Users should understand how long previous versions are retained and how to restore them.
Businesses should test recovery procedures before an emergency occurs.
What to do before sharing a file
Use this checklist:
- Confirm the correct file.
- Check the recipient.
- Select the lowest necessary permission.
- Avoid unrestricted links.
- Set an expiration date where available.
- Remove unnecessary sensitive information.
- Check the full folder contents.
- Confirm whether downloading is required.
- Protect the account with MFA.
- Review access after the task is complete.
What to do if a file was shared accidentally
If you shared a file with the wrong person:
- Remove their access immediately.
- Disable the public link.
- Check whether the file was downloaded.
- Review activity logs if available.
- Inform the appropriate person or security team.
- Change exposed passwords or credentials.
- Assess what information was included.
- Preserve evidence.
Do not simply delete the email notification and assume the access is gone.
What to do if your cloud account is compromised
Act quickly:
- Change the password.
- Sign out all active sessions.
- Enable or reset MFA.
- Review recovery information.
- Remove unknown devices.
- Review shared links.
- Check deleted and modified files.
- Remove suspicious connected applications.
- Restore affected files if necessary.
- Report the incident if it involves business data.
Check the connected email account as well.
Final advice
Cloud storage makes collaboration and backup easier, but convenience should not replace access control.
Keep files private by default, share only with the people who need them, limit permissions, protect the account with MFA, and remove old links and users.
Before sharing, ask:
- Who needs this file?
- What level of access do they need?
- How long should access remain active?
- What would happen if the link was forwarded?
Careful sharing protects personal information, customer data, and business documents.
You can also test your awareness through the Cybersecurity Quiz on BTSec Hub and practise protecting files, accounts, devices, and sensitive information.
Suggested Excerpt
Cloud files can be exposed through public links, incorrect permissions, phishing, and weak accounts. Learn how to share documents safely and protect personal and business data.