Simply telnet to the IPMI IP Address in port 49152 and do a specific GET request. You should get your users and passwords if you're compromised.
telnet server.example.com 49152
After the connection ask for
GET /PSBlock and watch the results, it should be something like this:
Connected to server.example.com.
Escape character is '^]'.
To solve this issue update the IPMI firmware to the latest version. The firmware is specific to your IPMI controller, so you should get the specified in Supermicro website.