My Google Analytics shows a very high increase of traffic from one ISP, being all unique visits coming from the same ISP and all of them using IE9/8/7/6. I'm getting 32% new (unique) visits, but now people stays 8min average, it was around 20min 3 days ago before this change. Pageviews remain the same.
My site is growing in traffic, but I'm getting red flags because I'm getting all this new visitors from the same ISP and all of them are using IE, also the site-stay is decreasing.
My bandwidth stills the same, CPU usage has not rised, which is weird if I'm really getting 30% new visits in two days.
The site runs on three servers with nginx and PHP5, I took a peek in the log to see if I was getting more hits per user than usual, but nothing weird there. Nothing new has been deployed to production.
EDIT: All the new uniques are coming from uninet/telmex. They come from direct traffic, no referers. The major ones still having the same numbers.
Any tips?