Moved to Malware group.
Identifying whether detection in DATs exists or not is difficult to say for certain as we would need hashes or samples to be able to tell you for sure. However, I found 35 hashes which appear to be different variants of this ransomware and they are all covered currently. If you have any specific files you are looking for information on, let us know and we can check for you.
Perhaps McAfee has named it (like so many other AV companies) with a different name:
Ransomware MongoLock Immediately Deletes Files, Formats Backup Drives
55 engines detected this file SHA-256 698be23b36765ac66f53c43c19ea84d9be0c3d7d81983726724df6173236defa