90% of the spam that I receive here originates at ubiquityservers.com. Either they have a very bad infection or they have a way where spammers can easily create an account without paying, install their spam spiders, and then move on to the next. I am considering blacklisting the entire ubiquityservers.com subnet from all of my sites.
Any website you create gets hit by the Ubiquity/Nobis spam services almost from the moment it goes live, day-in, day-out. Some ISPs and hosting companies have their difficult periods but it seems like Ubiquity are just setup to serve spammers. The worst IP blocks seem to have been signed over to a Romanian operation.
Here’s a write up on being hit from 35 different Ubiquity/Nobis IPs in 30 seconds and three other recent posts:
https://h5n1.toolz4schoolz.com/2011/02/ubiquity-servers-worst-spam-attack-yet/
https://www.ak47online.com/549/ubiquityservers-com-hosting-spammers/
https://werehosed.mvmanila.com/2011/01/14/spam-spam-spam/
https://www.xaviermedia.com/webbing/2011/01/19/how-to-protect-your-blog-from-spam/