Every time I try to connect to a site through HTTPS from my office computer, there is a Certificate Error thrown 2-3 times before showing the login screen. Till now I use to ignore this and click continue. But recently one of my collegue told me the possiblility of Man in the middle attack.

All I want to ask is, is it possible for them to track my passwords or account details by such method?

UPDATE: They are replacing the Certificate. For now, I activated 2-factor auth in Google.