Safari says "Please Update Internet Explorer"
In last two days, everytime I try to connect google.com (and once that I try to connect facebook.com), there pops up a message saying "WARNING! Your internet Explorer is out of date Please Update" though I never installed IE before. When I click OK, it directs me a suspicious (probably fraud) page saying that "OUTDATED BROWSER DETECTED" and wants me to install IE. You can check screenshots. This really disturbs me because I can't use google.com or google search anymore!
Can it be a virus or something?
PS: I started to see this after I installed Chrome, TunnelBear, Zenmate, Hotspot Shield (I uninstall the last two in a couple of minutes after installing). Can these softwares be suspicious?
As unsuccessful attempts, I reset Safari, clear cookies and restart the system... Don't work...
Please help!
Regards,
MacBook Pro (13-inch Mid 2012), OS X Mountain Lion (10.8.5)