PSAmsi is a tool for auditing and defeating AMSI signatures.
It's best utilized in a test environment to quickly create payloads you know will not be detected by a particular AntiMalware Provider, although it can be useful in certain situations outside of a test environment.
When using outside of a test environment, be sure to understand how PSAmsi works, as it can generate AMSI alerts.
You are only authorized to use PSAmsi (and payloads created with PSAmsi) on systems that you have permission to use it on. It was created for research purposes only.
A huge thanks to the following people whose code is used by PSAmsi: