Adware installers disguised as cracks have been used for a massive distribution of the STOP ransomware during the last month. 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. First starting with the .djvu extension, then switching to the .tro extension, a common practice used by sites that distribute software cracks is to utilize adware bundles in order to generate revenue. These bundles will normally install unwanted extensions, adware, clickers, and miners, but one bundler appears to
be turning a blind eye and has started distributing the STOP Ransomware as well.
Some of the reported cracks that are installing this ransomware include Windows activation cracks such as KMSPico, Cubase, Photoshop, antivirus software, and cracks for many other popular copyrighted software. From reports by infected users, it does not appear to be one particular crack site that is affected, but many different ones who are pushing similar adware bundles.
In this new variant, not much has changed and the developers continue to use the same approach. The main difference is in this version the ransomware will append the .rumba extension to a file’s name after it is encrypted as shown below.
In each folder that a file is encrypted, the ransomware will create a ransom note named _openme.txt that contains instructions on how to contact the attacker for payment instructions.
Encryption of personal information
INDICATORS OF COMPROMISE
Malware Hash (MD5/SHA1/SH256)
It is recommended to install legitimate and well-reputed adware blocker available in different browsers.