In December 2018, a new ransomware called Djvu, which could be a variant of STOP, was released that has been heavily promoted through crack downloads and adware bundles. Most of the victims stated that they became infected after downloading a software crack. This campaign has been very successful, with ID-Ransomware reporting numerous victims submitting files to their system on a daily basis. The good news is that it may be possible to receive help in recovering your files for free. If you are infected with STOP Ransomware (.djvu,.tro, or rumba), please see this post about using Michael Gillespie’s decryptor.
Source: https://www.bleepingcomputer.com/news/security/djvu-ransomware-spreading-new-tro-variant-through-cracks-and-adware-bundles/