Email VIRUS Infections

HTG Explains: Why You Can’t Get Infected Just By Opening an Email (and When You Can)

Email viruses are real, but computers aren’t infected just by opening emails anymore. Just opening an email to view it is safe – although attachments can still be dangerous to open.

Past security problems with Microsoft Outlook resulted in a lot of damage, and some people still believe that just opening an email is dangerous. This isn’t true.

Why Opening an Email is Safe

Emails are essentially text or HTML documents (web pages). Just like opening a text file or web page in your browser should be safe, opening an email message should also be safe. Whether you are using Hotmail, Gmail, Yahoo Mail, Outlook, Thunderbird, or another web-based or desktop email client, opening an email – even a suspicious looking one – should be safe.

However, some emails may try to infect you after you open them. They may contain malicious programs as attachments or have links to malicious websites full of malware and scams. You should only run trustworthy attachments – even if someone you trust sends you file attachment with a .exe file or another program file, you probably should not open it. They may be compromised.

As with everything on the web, you shouldn’t run programs that try to automatically download onto your computer after you click a link.

Why Opening Emails Was Once Unsafe

In the past, Microsoft Outlook had a serious security problem. Emails – which were once just plain text – are also allowed to contain HTML code: the same code that web pages like this one are written in. An Outlook vulnerability allowed emails to run JavaScript code and infect your computer. For this reason, just opening an email was potentially dangerous.

However, this vulnerability was fixed. Emails cannot use JavaScript. Modern email clients don’t even automatically display images in emails. As with web browsers, operating systems, and other computer programs, security holes are occasionally discovered and patched.

As long as you are using up-to-date software – including your mail client, browser, browser plugins, and operating system – you should be able to open email messages and view them without fear.

Email Safety Tips

File attachments and links in email can still present danger. Follow these best practices to stay safe:

• Keep Your Mail Client, Web Browser, and Operating System Updated: Software updates are important, as the bad guys regularly find holes and try to exploit them. Software updates close these holes and protect you. If you are running an outdated browser and email client, you could be compromised. (If you have Java installed, you should uninstall it or at least disable the browser plugin to protect yourself, too.)
• Use Antivirus Software: On Windows, antivirus software is an important layer of protection. It can help protect you from both mistakes and software bugs that allow malware to run without your permission.
• Don’t Run Dangerous Attachments: If you get a PDF file from someone, it’s probably safe to open (especially if your PDF reader is up-to-date). However, if you suddenly get an email with a .exe file or another potentially dangerous type of file you aren’t expecting – even if it’s from someone you know – you probably shouldn’t run the attachment. Exercise extreme caution with email attachments – they are still a common source of infection.
• Be Careful of Links: Clicking links should be safe, just as loading a website in your browser should be safe. However, if the link looks like it leads to a site packed with malware and acai berry scams, you probably shouldn’t click it. If you do click a link, don’t download and run any potentially dangerous files. You should also watch out for phishing – if you click a link in an email that appears to be from your bank and end up on a similar-looking website, it may not actually be your bank’s website, but a clever imposter.

For more information about dangerous phishing emails, read Online Security: Breaking Down the Anatomy of a Phishing Email.

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There are a variety of problems you could encounter with email: dangerous file attachments, scams that try to take your money, phishing emails that attempt to steal your personal data, and links to dangerous websites. However, just opening an email shouldn’t cause any problems.