Is webroot antivirus creating a fake alert?

My subscription(if that is what you call it) to webroot antivirus recently ran out,but I can still scan/sweep.It found a virus called fakealert.gen but I will have to purchase a new subscription to delete it.However,none of my other antivirus softwares can find this virus,and when I went into my computer files I found no trace of it.Is webroot trying to scare me into buying their antivirus?