Lawrence Abrams reports:
The STOP ransomware has seen very heavy distribution over the last month using adware installers disguised as cracks. This campaign continues with a new variant released over the past few days that appends the .rumba extension to the names of encrypted files.
Using adware bundles and software cracks as a new distribution method, STOP has become one of the most prolific ransomware infections we have seen in quite a while.
Read more on Bleeping Computer.