It was inevitable, I suppose. WhatsApp, the messaging service, allows documents to be sent through their service, so scammers are using the new feature to send virus infected documents to people.
The Independent is reporting that “Fake WhatsApp documents being used to trick people into downloading and installing viruses onto their phones”. The article is broadly correct though some of its details are shaky, we’ll talk about that in a little while.
It’s the same problem that we have with attachments to emails. There’s always the possibility that the file attachment is infected with a virus or malware.
Use the same caution and precautions as you would with email or other attachments.
Only open incoming files from known and trusted sources. If a document pops up from someone you’ve not heard of, even if it’s some official sounding source – beware. After all, what are the chances that a government department or company will start sending you instant messages ‘out of the blue’?
Look carefully at the file extension of the incoming file. For a short file name, it’s clearly visible in the name.
But for longer file names, the file extension disappears off the right side. It’s a long standing problem in Outlook which hackers take advantage of. They use a long file name to hide the type of document.
WhatsApp have taken a good step to preventing that. The file extension is displayed on a separate line, regardless of the file name length.
Thanks to Phil and Claude for sending file attachments to test.
The ‘Indie’ was a little misleading when their article said “documents like Excel spreadsheets and PDFs can include viruses.“. That’s not the whole story.
Update: the first report of attempted infection via WhatsApp comes from files called “NDA-ranked-8th-toughest-College-in-the-world-to-get-into.xls” and “NIA-selection-order-.xls” supposedly from from the National Defense Academy (NDA) and National Investigation Agency (NIA). According to the Economic Times of India.
It’s worth noting these are old style ‘.xls’ Excel files.
Excel files can contain viruses but not all Excel files have the same risk level. The old .xls worksheets are one way viruses are sent but the newer form .xlsx files are much less likely to contain an infection (an infected .xlsx is extremely rare).
PDF files have been known to contain infections but it’s been very rare.
It’s far more common for .doc .xls .exe .zip or .rar files to contain a virus or malware.