We recently reported that CryptoWall 3.0 has allegedly caused over $325 million in annual damages. CryptoWall first emerged in April 2014. Its first major upgrade was dubbed CryptoWall 2.0, and first emerged in October 2014. CryptoWall 3.0 then emerged in January 2015 and terrorized organizations on a global scale. Now, in November 2015, CryptoWall 4.0 has emerged.
New features such as the encryption of the names and extensions of affected files have emerged with the 4th member of the CryptoWall family. Additionally, CryptoWall 4.0 has changed the name of its ransom notes to HELP_YOUR_FILES.TXTand HELP_YOUR_FILES.HTML.
The ransom note itself contains payment instructions and also mocks the infected user.
However, it’s likely that exploit kits will begin to deliver CW4 as a payload very soon, if they are not already (especially the Angler EK).
The C&C communication and behavioural activity of CryptoWall 4.0’s payload is quite similar to its earlier versions. The specific sample that I have analyzed performed the following actions, as can be evidenced by the below images.
Added Registry Keys
About the Author Michael Fratello
Edited by Pierluigi Paganini
(Security Affairs – CryptoWall 4.0, ransomware)