@bvitorio,
this seems to be a variant of Scarab-Danger Ransomware.
Multiple similar email addresses to Jabber have been used by this cryptovirus in the past.
You can read more in the article here:
Remove Scarab-Danger RansomwareA free decryption method does not exist. Some people say that there is a decrypter, but you have to pay for it and takes 7 days to decrypt the files, which is a lot of load and use of computer resources and power.
Very unfortunate that it has hit your backup.
Just wait for the decryption tool to be optimised and released for free, if you can wait. It might never happen or it could take months/years, but unless you pay to decryption experts, I don't see a way to recover the files for free.
Maybe try a data recovery tool, but it is unknown if the ransomware deletes the files before encrypting copies of them.
Best Regards,
Execute