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The dangers of links and attachments in emails

We continue our Email Security Best Practices campaign this week as we now turn our attention onto the dangers of links and attachments in emails.

Every day, millions of people across the country and around the world send an email. It’s a popular use to distribute files as attachments to a person quickly and easily.

Unfortunately, this functionality creates an opportunity for the distribution of viruses – most notable malware and ransomware.

Below are several points you should be made aware of when it comes to opening attachments or clicking on suspicious links via email.

Spotting a dangerous email attachment

The easiest way to identify whether a file is dangerous is by its file extension. For example, a file with the .exe file extension is a Windows programme and should not be opened. Many email services will block such attachments.

Potentially dangerous file extensions that can run code and may contain a virus are .msi, .bat, .cmd, .hta, .scr, .pif, .reg and many more. A general rule is you should only open files with attachments that you know are safe.

What about dangerous links in emails

Malware, viruses and other types of malicious material can be easily downloaded to your server or computer by clicking a link – it doesn’t have to be just an attachment.

Watch out for unfamiliar links – especially if somebody is claiming to share a file with you from places like Dropbox or OneDrive.

It always worth noting that if you see a link in an email such as – – it might not necessarily take you to where the text says. Hover over a link and a box tends to indicate where you will be heading if you click it. If it looks unfamiliar – DONT CLICK IT.

Watch out for archives

A common tactic used by cybercriminals is to email you malicious file attachments in an archive – especially an encrypted one. You may receive an email with either a .zip or .rar file and its password. You may be instructed to download the archive file and extract its contents with the password to access them.

These type of files are particularly dangerous as the password-protection on the archive prevents antivirus programs from examining it, so it is possible that the archive could contain malware. If your not sure – don’t open the file.

For further information

Arc Systems have teamed up with Mimecast to bring you this series of best practices.

If you have any questions, are concerned about your email security or want an initial chat on how Mimecast can help your business, don’t hesitate to contact Arc Systems for further details.

They can be contacted on, or you can speak to one of their representatives by calling 01268 288100.