Avast Decryption Tool for BTCWare can unlock BTCWare, a ransomware strain that first appeared in March 2017 and has spawned five known five variants. All the Avast Decryption Tools are available in one zip here.

The variants can be distinguished by encrypted file extension. The ransomware uses two different encryption methods – RC4 and AES 192.

Encrypted file names will have the following format:

foobar.docx.[sql772@aol.com].theva
foobar.docx.[no.xop@protonmail.ch].cryptobyte
foobar.bmp.[no.btc@protonmail.ch].cryptowin
foobar.bmp.[no.btcw@protonmail.ch].btcware
foobar.docx.onyon

Furthermore, one of the following files can be found on the PC
Key.dat on %USERPROFILE%\Desktop
1.bmp in %USERPROFILE%\AppData\Roaming
#_README_#.inf or !#_DECRYPT_#!.inf in each folder with at least one encrypted file.

After encrypting your files, the desktop wallpaper is changed, as seen in the screenshot below.

Similar:

Which Anti-Malware App Is Best and Can It Run Alongside My Antivirus

What's the Best Antivirus and Is Windows Defender Good Enough?

Windows Device Performance & Health Explained

How to Tell the Difference Between a Virus and a False Positive

How to Manage Windows Defender Antivirus Found Threats

What to Do When Your Norton or McAfee Antivirus Expire