for instance if us server is down, it will automatically changes to europe server. And after us server is up, it will go back to us server.
FAILOVER
Use "epools.txt" and "dpools.txt" files to specify additional pools.
These files have text format, one pool per line. Every pool has 3 connection attempts.
Miner disconnects automatically if pool does not send new jobs for a long time or if pool rejects too many shares.
Pool specified in the command line is "main" pool, miner will try to return to it every 30 minutes if it has to use some different pool from the list.
If no pool was specified in the command line then first pool in the failover pools list is main pool.
You can change 30 minutes time period to some different value with "-ftime" option, or use "-ftime 0" to disable switching to main pool.
This is normal, several antivirus programs detect it as a virus.