It's a STOP DJVU variant. It is safe to assume that anyone who can decrypt is either a scam or simply acts as middle man between you and the people who created the ransomware.
Now, that's an option of course, pay. I have witnessed chats between victim and 'hackers' or middleman that did not end well. Price kept being raised or in the end no solution was offered to decrypt the data. Or was offered but failed.
With regards to the Emsisoft tool: There's no guarantee but it is possible decryption will be available some time in future. Emsisoft does not announce these updates.
Recovery options (without decryption/payment)
1.
I have seen cases where in deeper nested folders files were not actually encrypted, so check that.
2.
The ransomware m.o.: open file > read data > encrypt data > save encrypted data to NEW file > delete original file. That means depending on circumstances there's a chance deleted data, at least partially survives the onslaught. Circumstances you can consider is HDD or SSD (if the latter chances probably close to zero) and free space vs. used space. Using JpegDigger some people have reported they were able to recover some times upto 30% of their original JPEGs but that's IMO a very optimistic figure (I didn't check their math). This purely to illustrate original files potentially survive. You can use a RAW scanner that supports more file types to see if other file types survived too.
3.
The ransomware encrypts only 153600 bytes. That means if you have a large video or JPEG for example, most data 'survives'. File repair aims to make the remaining non encrypted data viewable/usable/playable. Files tend to start with some kind of 'header'. This header can be stolen from a similar file, for example a video that was shot with the same camera. We then adapt the header for the partially encrypted file, update pointers etc.. Examples
https://youtu.be/3AKJ27sZ9_E and
https://youtu.be/bBqo8ePpQ5M.