While email attachments are a popular and convenient way to send documents, they are also a common source of viruses. Use caution when opening attachments, even if they appear to be from someone you know.
These tips are based on recommendations from the Cybersecurity & Infrastructure Security Agency. https://us-cert.cisa.gov/
Be wary of unsolicited attachments, even from people you know. Just because an email message looks like it came from someone you know does not mean that it did. Many viruses can "spoof" the return address, making it look like the message came from someone else. If you can, check with the person who supposedly sent the message to make sure it's legitimate before opening any attachments.
Keep software up to date. Install software patches so that attackers can't take advantage of known problems or vulnerabilities .
Trust your instincts.If an email or email attachment seems suspicious, don't open it, even if your antivirus software indicates that the message is clean. Attackers are constantly releasing new viruses, and the antivirus software might not have the signature. At the very least, contact the person who supposedly sent the message to make sure it's legitimate before you open the attachment. However, especially in the case of forwards, even messages sent by a legitimate sender might contain a virus. If something about the email or the attachment makes you uncomfortable, there may be a good reason. Don't let your curiosity put your computer at risk.
Save and scan any attachments before opening them. If you have to open an attachment before you can verify the source, take the following steps:
- Be sure the signatures in your antivirus software are up to date.
- Save the file to your computer or a disk.
- Manually scan the file using your antivirus software.
- If the file is clean and doesn't seem suspicious, go ahead and open it.