Once you convert lead, Few fields on lead should be reset so that sensitive information should not be queried using SOQL. How to get this done

Once you convert lead, Few fields on lead should be reset so that sensitive information should not be queried using SOQL. How to get this done

Once lead is converted, its READ ONLY. we cannot update it using Apex or Trigger. However we can use “Before Update” trigger on lead and check for fiels “IsConverted“. If its true means lead is going to be converted so reset all fields in that case