As far as I know, you cannot access those agents anymore for this purpose, so there is no regular way to bump your sec status above 5.0.
However, there are occasionally events that can do this. Not sure if it was a bug, but after running the Guristas event a couple months back, they gave me something like a 0.01 bump for each site and I wound up at 5.11 after the thing ended. I don’t believe this was the case for the last event, not sure if this will happen again.