About Petya RansomwareThe initial ransomware payload has been modified and now contains these new traits:
- Petya spreads through malicious Office attachments and email. This gets through the front door and onto any target system that can be exploited via social engineering.
- Once the malware is installed, it looks for other systems to exploit using EternalBlue. This is the same vulnerability as WannaCry to exploit any system via lateral movement.
- Petya also contains malware to scrape memory and the file system for passwords and execute psexec against remote targets to propagate the infection. This will compromise hosts even if they are patched for EthernalBlue and leverage administrator credentials it discovers during its interrogation of the system.
- Encryption is at a low level using the Master File Tree tables for NTFS and overwrites the Master Boot Record (MBR) with a ransomware warning. This is why a reboot must be done instantly or the MBR can be compromised.
- Remove administrator rights from end users
- Implement application control for only trusted applications
- Perform vulnerability assessment and install security patches promptly
- Train team members on how to identify phishing emails
- Disable application (specifically MS Office) macros