I will create custom parser in IBM security qradar for the unknown logs

Detecting a right event that points to something malicious is like finding a needle from a heap. Deploying SIEM is just not the end, one must have the visibility across all the integrated logs to gain actual insight about what's going-on in your network. If the log source is integrated and SIEM is unable to parse the payload properly, then you might missing some very important aspect of threat hunting. Custom parsers can be written for unknown logs from supported log sources or to parse the logs all the way from an unsupported log source.

If you need to gain visibility and get efficiency in your threat hunting journey, don't wait to ping me to write custom parser in IBM QRadar.