Unknown network traffic reported by little snitch

[geomacbcn]

In the end I discovered the problem was caused by printer sharing being on in sharing preferences. I activated it 2 days ago and since then my little snitch was being bombarded by connection requests. everything back to normal now.

 

[MarcusH]

You can not trust anything on that system. If they had root/admin access they can make it appear you have a clean system...

Forgive maybe a stupid question, but would this sort of problem be invisible to a virus checker?