Talos has updated its TeslaCrypt decryptor tool, which now works with any version of this variant of the ransomware variant. ESET took that information and released a decryptor for TeslaCrypt versions 3 & 4. Details about the cryptographic shortfalls in each version, as well as the source code for the decryption tool, are available here. The authors of the TeslaCrypt ransomware surprisingly decided to stop their activities and released their master key in May 2016. You can download the decryptor here.”]
Source: https://blog.talosintelligence.com/2016/06/teslacrypt-decryptor.html