Problem logging into my account at my local library

hello when I try to access my facebook account at my local library the below message comes up, I can access it on my phone and on my tablet and mac but not at the library other users can access their face book accounts it just seems to be me do you know what the problem might be and how I can fix it please thank you

It looks like your computer is being affected by malware. We’ll help you fix the problem to keep your account secure and prevent malware from spreading to friends.
Malware is software that tries to steal personal information and causes problems when you use Facebook. Clicking or sharing links that contain spam can give your computer malware