[SUPERNOVA](https://attack.mitre.org/software/S0578) is an in-memory web shell written in .NET C#. It was discovered in November 2020 during the investigation of [APT29](https://attack.mitre.org/groups/G0016)'s SolarWinds cyber operation but determined to be unrelated. Subsequent analysis suggests [SUPERNOVA](https://attack.mitre.org/software/S0578) may have been used by the China-based threat group SPIRAL.(Citation: Guidepoint SUPERNOVA Dec 2020)(Citation: Unit42 SUPERNOVA Dec 2020)(Citation: SolarWinds Advisory Dec 2020)(Citation: CISA Supernova Jan 2021)(Citation: Microsoft Analyzing Solorigate Dec 2020)