The .SSIRAF file extension indicates a Proton/Shinra ransomware infection, designed to encrypt files and demand payment, often leaving a text file with instructions. Immediate actions include disconnecting the affected device, identifying the variant via tools like the No More Ransom Project, and attempting recovery from backups rather than paying the ransom. To learn more about identifying this specific ransomware strain, visit the Bleeping Computer forum discussion . Recovering from Ransomware with an Online Backup