What are two security risks of sending confidential files via email?

Email is one of the most popular and convenient ways to share confidential files in both personal and professional settings. Its accessibility and ease of use make it a go-to tool for communication and file sharing worldwide.

However, despite its widespread use, email is not always the most secure method for transmitting sensitive information. Without proper safeguards, it can expose users to significant risks.

This article focuses on exploring what are two security risks of sending confidential files via email: the potential for interception during transmission and vulnerabilities due to phishing attacks.

Risk 1: Email interception during transmission

Email transmission of confidential information faces a major security threat because attackers can intercept data during its transit. Unsecured network transmission of emails creates security risks because attackers can use packet sniffers to intercept data during transmission.

Emails do not reach their destination inbox through a direct path from your device. The transmission process takes email through multiple servers and networks which frequently extend across various geographical areas. Every stop during data transmission creates a security risk that becomes more dangerous when the servers and connections lack encryption protection. Attackers who lack encryption access can intercept emails to read sensitive information including personal data and business documents and financial data.

Open network connections such as public Wi-Fi create a high risk of interception for users. Your communications become vulnerable to cybercriminals because public networks fail to implement proper encryption protocols. Checking your email in public locations such as coffee shops or airports exposes your data to attack by network-based attackers who may intercept your information.

The implementation of encryption stands as the most powerful method to reduce this security risk. Secure email transmissions that utilize Transport Layer Security (TLS) convert messages into unreadable formats while they travel through the network thus protecting them from unauthorized access. The effectiveness of encryption depends on both the sender and recipient having servers which support and implement encryption protocols. The absence of encryption in any segment of the chain makes data vulnerable to interception by unauthorized parties.

A Virtual Private Network (VPN) provides additional security through encryption of the entire Internet connection which protects email interception attempts particularly on unsecured public networks.

To reduce the risk of interception, users should:

• Avoid sending sensitive information over public or unsecured networks.

• Use secure email services that enforce end-to-end encryption. Services like ProtonMail or Tutanota encrypt messages by default, ensuring privacy without extra setup.

• Manually encrypt sensitive emails: Use PGP or S/MIME to protect emails in standard services like Gmail or Outlook, ensuring only the recipient can read them.

• Verify that the email provider supports TLS or other encryption standards.

• Enable two-factor authentication (2FA) to protect email accounts from unauthorized access.

• Use a VPN when accessing email on public Wi-Fi to prevent network-based attacks.

Example scenario: the risks of unencrypted email

Imagine a business professional sending sensitive client information via email while connected to a public Wi-Fi network at a coffee shop. Unknown to them, a hacker on the same network is using a packet sniffer to intercept unencrypted data. The hacker gains access to confidential details, such as financial records or personal identification numbers, simply because the email connection lacked proper encryption. This breach not only compromises the client’s information but also puts the sender’s reputation and business at risk.

Preventive measures to stay secure

To prevent such scenarios, it's essential to take proactive steps:

1. Use encrypted email services: Choose email providers that enforce end-to-end encryption or at least use Transport Layer Security (TLS) to secure email transmissions. This ensures that the contents of your emails are protected during their journey across networks.

2. Attach encrypted files: If your email service doesn't support end-to-end encryption, consider encrypting the files you're sending. This adds an additional layer of security, as the recipient will need a password or decryption key to access the file.

3. Avoid unsecured networks: Refrain from sending sensitive information over public Wi-Fi or any network that isn't secured. If using such a network is unavoidable, ensure you use a Virtual Private Network (VPN) to encrypt your Internet connection.

Risk 2: Human error — accidental misdelivery of sensitive information

A frequent risk associated with email communication is human error, particularly accidental misdelivery. A simple mistake, such as mistyping an email address or selecting the wrong recipient from an autofill suggestion, can lead to confidential information being sent to the wrong person.

Such incidents may result in:

• Data breaches: Sensitive company information could be exposed to unauthorized parties.

• Reputational damage: Misdelivery of confidential data to a competitor or an unintended client can erode trust and harm professional relationships.

• Legal or regulatory consequences: Depending on the nature of the data and industry regulations, accidental leaks can result in compliance violations and financial penalties.

Example scenario: the dangers of misdelivery

An employee is preparing an email with confidential financial records meant for internal review by their manager. While typing the recipient's email address, they mistakenly select a client’s email from the autofill suggestions. The sensitive financial data is now in the hands of an external party, creating a serious breach of confidentiality.

Preventive measures to avoid misdelivery

Even though human error is inevitable, certain precautions can significantly reduce the chances of misdelivery and its potential consequences.

• Double-check recipient details: Always verify the recipient's email address before sending sensitive information. Pay extra attention when using autofill or bulk email features.

• Use delayed sending features: Enable a delay of a few seconds or minutes before an email is sent. This allows time to review and correct mistakes.

• Restrict email permissions: Where possible, configure email settings to prevent unauthorized forwarding or recall emails sent in error.

• Provide training and guidelines: Educate employees on best practices for handling sensitive information via email.

Unauthorized access and account compromise

Cybercriminals constantly attempt to breach email accounts to steal sensitive information or exploit trust between contacts. Securing your own account is the first line of defense, but even if your email is protected, attackers may still target your colleagues, clients, or partners to manipulate you.

How cybercriminals exploit compromised accounts

Depending on whether the compromised account belongs to you or someone else, attackers can exploit it in different ways to extract sensitive information.

If your own account is compromised:

• Unauthorized access to sensitive data: Attackers can read, delete, or steal confidential emails.

• Identity theft: Hackers may impersonate you to deceive colleagues, clients, or partners.

• Account takeover for further attacks: A compromised account can be used to reset passwords for other services or to spread malware.

If someone else's account is compromised:

• Social engineering attacks: You may receive emails from seemingly trusted contacts requesting confidential details or urgent actions.

• Phishing distribution: Hackers can use a familiar account to send malicious links or attachments, making them look more convincing.

• Internal fraud: Attackers may manipulate conversations to authorize fake financial transactions or gain access to sensitive business data.

Example scenarios: how a hacked account can be exploited

Scenario 1: A personal account breach

You fall victim to a phishing attack, unknowingly giving hackers access to your email account. Once inside, they use your compromised account to send requests for sensitive company documents to your colleagues. Since the emails appear to come from you, your coworkers trust them and comply without suspicion. Without proper verification, confidential information is exposed, increasing the risk of data breaches, financial fraud, or further attacks within the organization.

Scenario 2: A compromised contact's account

You get an urgent email from your boss asking for a wire transfer to a new account. Everything seems normal — it contains the correct address and appears authentic. But in reality, your boss's account has been compromised by cybercriminals who sent the deceptive message. The company risks major financial losses when you process the request without confirming it through alternative channels.

Preventive measures against unauthorized access

Protecting your email account is crucial, but it's equally important to recognize when someone else's account has been compromised. Cybercriminals can exploit both scenarios to steal information, spread malware, or commit fraud. The following measures will help you secure your own account and identify compromised accounts of others before they can be used against you.

Protecting your own account from being hacked

• Enable multi-factor authentication (MFA): Even if attackers steal your password, MFA adds an extra layer of security.

• Use strong, unique passwords: Avoid reusing passwords and consider a password manager for better security.

• Monitor login activity: Set up alerts for logins from unknown devices or locations.

• Be cautious of potential phishing attempts: Never click on suspicious links or download unexpected attachments, even from known contacts.

• Keep your email recovery options secure: Ensure your backup email and phone number are up to date to regain access if needed.

Identifying and handling emails from compromised accounts

• Verify unusual requests: If an email asks for sensitive information or urgent financial actions, confirm it via a separate communication channel.

• Look for red flags in communication: Be cautious of unexpected changes in tone, grammar mistakes, or unusual urgency—these can indicate a hacked account.

• Avoid interacting with suspicious emails: Do not click links, download attachments, or reply until you confirm the sender's authenticity.

• Report and alert the sender: If you suspect someone's account is compromised, notify them through another channel so they can take action.

Conclusion

Email remains a widely used tool for communication and file sharing, but it comes with significant risks. Attackers can exploit both direct breaches of your account and compromised accounts of your contacts to steal sensitive information, spread malware, or commit fraud.

To mitigate these risks, a multi-layered approach to email security is essential. Protecting your own account through encryption, multi-factor authentication, and strong passwords prevents unauthorized access, while recognizing signs of compromised accounts—such as unusual requests or suspicious communication patterns—helps prevent social engineering attacks.

Additionally, considering secure alternatives like encrypted messaging platforms and secure file-sharing services can further reduce exposure to cyber threats. By staying vigilant and proactive, individuals and businesses can significantly enhance their email security and reduce the likelihood of costly data breaches.