Note: This blog post discusses active research by Talos into a new threat. This information should be considered preliminary and will be updated as research continues.
Update 2017-07-06 12:30 EDT: Updated to explain the modified DoublePulsar backdoor.
Since the SamSam attacks that targeted US healthcare entities in March 2016, Talos has been concerned about the proliferation of malware via unpatched network vulnerabilities. In May 2017, WannaCry ransomware took advantage of a vulnerability in SMBv1 and spread like wildfire across the Internet.
Today a new malware variant has surfaced that is distinct enough from Petya that people have referred to it by various names such as Petrwrap and GoldenEye. Talos is identifying this new malware variant as Nyetya. The sample leverages EternalBlue, EternalRomance, WMI, and PsExec for lateral movement inside an affected network. This behavior is detailed later in the blog under "Malware Functionality". Unlike WannaCry, Nyetya does not appear to contain an external scanning component.
The identification of the initial vector is still under investigation. We have observed
no use of email or Office documents as a delivery mechanism for this malware. We believe that infections are associated with software update systems for a Ukrainian tax accounting package called MeDoc. Talos is investigating this currently.
Given the circumstances of this attack, Talos assesses with high confidence that the intent of the actor behind Nyetya was destructive in nature and not economically motivated. Talos strongly recommends users and organizations decline to pay the ransom. Any attempts to obtain a decryption key will be fruitless as the associated mailbox used for payment verification and decryption key sharing has been shut down by the posteo.de. This renders any successful payment as useless as there is no method of communication available for this actor to use to verify payments from victims or distribute decryption keys once ransom payments have been received. There is also no method used by the malware to directly connect to command and control for remote unlocking.