No. Not for yourself. But as jimlynch pointed out below, it would still be a good idea to have it for those poor folks out there stuck with Windows. You might pas on a previously infected file to someone who will run it in Office and suddenly have to do business with a ransomware thief.
That being said, your own files, which you can read/write/delete, are theoretically vulnerable to anyone who can get to your system with your privileges. That hasn't happened yet with Linux, to my knowledge, but the point is BACK UP. Keep everything you want to save in your home directory backed up daily on a different drive just in case anything malicious ever does hit the Linux desktop. That protects you from hardware failure as well.