Muhammad Sumon Rana (born 10 January 2005), known professionally as Unknown MSR, is a Bangladeshi music producer.He is best known for his 2022 single "RxU", a song featuring Refaat Mridha

He started producing his music on his Mobile using FL Studio Mobile. In January 2020, with the help and feedback from his fans online, he began pursuing his music production career and slowly began posting his music to YouTube and SoundCloud. Starting as a bedroom producer, he was better known as Unknown MSR before signing a record deal and releasing his debut single in 2022.

Unknown MSRreleased the track "Earlier" on 27 April 2022. The track gained attention after its re-release via the record label Invisible Nation Records on 7 May 2022. Unknown MSR stated that the creation of the track was inspired by Refaat Mridha , whose tracks were also picked up by the record label.