Use wfuzz or ffuf to enumerate s3

gistfile1.txt

Ffuf (faster):
ffuf -u "https://s3.REGION.amazonaws.com/COMPANYDELIMITERENVIRONMENT" -w "aws-regions.txt:REGION" -w "company.txt:COMPANY" -w "delimiters.txt:DELIMITER" -w "/usr/share/seclists/Discovery/DNS/subdomains-top1million-5000.txt:ENVIRONMENT" -mc 200 -v


Wfuzz:
wfuzz -u "https://s3.FUZZ.amazonaws.com/FUZ2ZFUZ3ZFUZ4Z" -w aws-regions.txt -w company.txt -w delimiters.txt -w "/usr/share/seclists/Discovery/DNS/subdomains-top1million-5000.txt" --sc 200 -v -t 50

The files:

company.txt:
You can either hard-code the company you're targetting in the url and skip this file or put a few variations in this file.

delimiters.txt:
-
.
_

aws-regions.txt:
us-west-1
us-west-2
us-east-1
us-east-2
cn-north-1
cn-northwest-1
eu-central-1
eu-north-1
eu-west-1
eu-west-2
eu-west-3
ap-northeast-1
ap-northeast-2
ap-northeast-3
ap-south-1
ap-southeast-1
ap-southeast-2
ca-central-1
me-south-1
sa-east-1
us-gov-east-1
us-gov-west-1
ap-east-1