Any attachments that are .zip and .exe files are potentially very dangerous and viruses are often spread this way. Viruses are effectively small software programs which are typically buried within a file and downloaded without you being aware. Once the attachment is opened, the virus is activated and the damage is done. This could be to damage your system, infecting files which you then pass on to others, theft of personal details or sending itself to those email addresses in your email address book.
Emails are frequently blocked by antivirus software due to these types of attachments but Microsoft Office attachments can also be equally as dangerous. Office files – such Word .doc / .docx, Excel .xls / .xlsx and Abobe pdf – are also frequently used to distribute viruses. Microsoft Word files are particularly vulnerable due to the fact that they are commonly exchanged and there is a lack of awareness concerning the risks. Using macros (code that can automate tasks in applications such as Word and Excel), cyber criminals can write viruses which is then sent as part of a standard Office application.
As well as crude attempts to send viruses through mass mailings, more sophisticated methods are used such as purporting to be the sender of an important message such as one from your bank, delivery companies and the HMRC, etc.
So when it comes to keeping yourself protected from potential spam and cybercrime, the advice is to treat attachments – whether from known or unknown senders – with extreme caution and only too open if to you are expecting something. A good antivirus package also massively helps as if a rogue attachment is opened by mistake it should stop it from doing any damage.