Should You Open an Unexpected Attachment?
Check an unexpected file with its sender before opening it.
Free video lesson · 1:13
Should You Open an Unexpected Attachment?
Phishing Awareness for Beginners
Music: “Thinking Music” by Kevin MacLeod. Creative Commons Attribution 4.0.
Check an unexpected file with its sender before opening it.
Read the video transcript
An attachment is a file sent with a message. It might be a worksheet or photo. Some files are harmless. Others are designed to run harmful software or lead you into a scam.
Imagine a message from a classmate with a file called Trip Photos. You were not expecting any photos. The friendly name does not tell you what the file will do when opened.
Leave the attachment closed while you check. Contact your classmate through a trusted conversation. Ask whether they sent that file and what it is for. Do not use the suspicious message to verify itself.
If a file asks you to switch off protection or enable extra features before you can view it, stop. Do not follow those instructions just because they appear inside a document.
For school or work files, ask your support team to help check anything unusual. You need not be a file expert. Confirm unexpected attachments before opening them.
For another clear example, watch Can You Trust an Email Sender Name? Then try What Should You Do After Clicking a Phishing Link?
The short answer
An attachment is a file sent with a message. It might be a worksheet or photo. Some files are harmless. Others are designed to run harmful software or lead you into a scam.
A simple example
Imagine a message from a classmate with a file called Trip Photos. You were not expecting any photos. The friendly name does not tell you what the file will do when opened.
Leave the attachment closed while you check. Contact your classmate through a trusted conversation. Ask whether they sent that file and what it is for. Do not use the suspicious message to verify itself.
If a file asks you to switch off protection or enable extra features before you can view it, stop. Do not follow those instructions just because they appear inside a document.
For school or work files, ask your support team to help check anything unusual. You need not be a file expert. Confirm unexpected attachments before opening them.
Put it into practice
- Keep an unexpected file closed while you check who sent it and why.
- Ask the sender using a separate, trusted conversation.
- Stop if a file asks you to disable protection or enable extra features.
Check your understanding
An attachment is named Homework.pdf. Does the name prove it is harmless?
Answer
No. A filename is a label. Confirm an unexpected file before opening it, and ask for help if something is unusual.
Explore next
Follow the free video course one question at a time. Teams can practise these habits through security training. For the cryptography protecting your systems, explore a cryptography audit.