Create a stand-alone bits job PBA

[VakarisZ]

Is your feature request related to a problem? Please describe.
We provide bits job attack technique in the report but there's almost no way for user to trigger it. It will only trigger in an uncommon cases: elasticsearch exploit succeeded or monkey upload command via powershell failed, so a backup bits job was used.

Describe the solution you'd like
Create a dedicated bits job. This job could be used to download the same executable used for "Signed Script Proxy Execution" PBA.

Describe alternatives you've considered
Please describe alternative solutions or features you have considered.

[cakekoa]

PBAs are being removed in #2442