Can you get a virus/malware/spyware from visiting a website on a mac?

I accidentally clicked an image in google images that could have come from a dodgy site and I'm worried I may have unknowingly allowed a virus/malware/spyware into my mac. The firewall is on and I need a password to install things. I also ran iAntivirus and it came back clean but I'm not sure how reliable it is.