Malware
BitPyLock
Bitpylock is a ransomware that encrypts files by using asymmetric keys and puts '.bitpy' as suffix once the encryption phase ended.
BitPyLock is a Windows malware family.
Background
Bitpylock is ransomware that relies on asymmetric keys to encrypt files, appending the '.bitpy' suffix once encryption finishes. It drops a ransom note named "# # HELP_TO_DECRYPT_YOUR_FILES # .html" onto the victim's Desktop. At the time of analysis the demand stood at 0.8 BTC, with contact handled through the email helpbitpy@cock.li.
Source: Malpedia (Fraunhofer FKIE).