Avast Decryption Tool for Stampado unlocks files encrypted by the Stampado ransomware; it has been in circulation since August 2016. All the Avast Decryption Tools are available in one zip here.
This particular strain is written with the AutoIt script tool and is still being sold on the dark web as new variants keep emerging, keeping it viable. The Stampado ransomware will add a .locked extension to any file it has encrypted. Additionally, there are some variants that also encrypt the filename itself, so they may look either like document.docx.locked or 85451F3CCCE348256B549378804965CD8564065FC3F8.locked.
If Stampado has encrypted your files, you will receive a ransom note similar to those shown in the screenshots below.