Mac Virus wants Keychain

2 days ago I came back to my macbook air after lunch and it was asking me all sorts of password entry requests: close one the next one pops up.
"accountsd wants to use the "login" keychain. Please enter the keychain password."
"AddressBookSourcesSync wants to use the "login" keychain".
"CalendarAgent wants to use the "login" keychain."
"com.apple.iCloudHelper.xpc wants to use the "login" keychain"
"Messages Agent wants to use the "login" keychain."
"Safari wants to use the "login" keychain."
 
I was able to install Webroot using a flash drive and it detected over 50 threats but could not kill the virus. the popups are still there and it overruns the CPU by replicating itself renderingthe computer slow. I was able to remove and block many of teh files (familiar reference names are: spigot, com.apple.XXXX)
Does anyone know what this is and how I can kill it?? It's locked me out of cloud functionality and the ability to isolate the threat manually. i'm no IT pro and can use any help I can get. Thanks in advance.