Tagged: Petya Ransomware

Ways to protect your computers from Petya Ransomware

Some CERT recommendations to better protect your computers from becoming infected by Petya Ransomware:

    • Perform regular backups of all critical information to limit the impact of data or system loss and to help expedite the recovery process. Ideally, this data should be kept on a separate device, and backups should be stored offline.
    • Applocker policies to block execution of files having name perfc.dat as well as psexec.exe utility from sysinternals.
    • Don’t open attachments in unsolicited e-mails, even if they come from people in your contact list, and never click on a URL contained in an unsolicited e-mail, even if the link seems benign. In cases of genuine URLs close out the e-mail and go to the organization’s website directly through browser.
    • Restrict execution of powershell /WSCRIPT/ PSEXEC / WMIC in enterprise environment Ensure installation and use of the latest version (currently v5.0) of PowerShell, with enhanced logging enabled. script block logging, and transcription enabled. Send the associated logs to a centralized log repository for monitoring and analysis.
    • Establish a Sender Policy Framework (SPF),Domain Message Authentication Reporting and Conformance (DMARC), and DomainKeys Identified Mail (DKIM) for your domain, which is an email validation system designed to prevent spam by detecting email spoofing by which most of the ransomware samples successfully reaches the corporate email boxes.
    • Application whitelisting/Strict implementation of Software Restriction Policies (SRP) to block binaries running from %APPDATA%, %PROGRAMDATA% and %TEMP% paths. Ransomware sample drops and executes generally from these locations. Enforce application whitelisting on all endpoint workstations.
    • Deploy web and email filters on the network. Configure these devices to scan for known bad domains, sources, and addresses; block these before receiving and downloading messages. Scan all emails, attachments, and downloads both on the host and at the mail gateway with a reputable antivirus solution.
    • Disable macros in Microsoft Office products. Some Office products allow for the disabling of macros that originate from outside of an organization and can provide a hybrid approach when the organization depends on the legitimate use of macros. For Windows, specific settings can block macros originating from the Internet from running.
    • Configure access controls including file, directory, and network share permissions with least privilege in mind. If a user only needs to read specific files, they should not have write access to those files, directories, or shares.
    • Disable remote Desktop Connections, employ least-privileged accounts.

Click on this link to view the prior coverage about WannaCry Ransomware found on Uniquely Toronto.

 

Posted by: Vincent Banial

 

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Find the Key needed to unencrypt a Hard Drive encrypted by Petya Ransomware

Click on this link to visit the GitHub site where Leo Stone has posted some code which might just figure out the key required to unencrypt a Hard Drive encrypted by Petya Ransomeware. He suggests to try finding the key using an image copy of the Petya encrypted Hard Disk,. That way the original may not be harmed.  

Disclaimer: if you use Leo Stone’s code and method, you do so at your own risk. Loe also suggested to make and use an image copy of the encrypted hard Drive so as not to potentially damage the original. Leo’s code may find the key, or it may not. Playing around with the encrypted Hard Drive may damage it to the point that even if you pay the Ransom, you may not be able to reteive your data from said hard drive. I again state that following Loe Stone’s method as posted on GitHub is done at your own risk. Do your own Due Diligence. You could lose all the data on the hard drive.

Posted by Vincent Banial

Petya Ransomware Major Global Attack

WannaCry Ransomware paved the way by showing how to quickly spread across the Global Internet. It focused on on a vulnerability with Windows SMB which had been there for years and only exploited by Nation State employed Hackers.

Petya Ransonware, as has been named by the Security Staff at Kaspersky Lab, learned much from the WannaCry outbreak. Petya Ransomware has spread to thousands of computers at major institutions across the Globe. Petya ransomware is just starting. This is a major Ransomware attack.

It is basically a Worm which was first spread by malicious XL spreadsheets. Once on a network it stays in memory and as such is no so easy to detect and protect against. It looks like it is also focusing on the Windows SMB protocol and the Ports which support SMB.No wonder the focus on SMB as Petya use EternalBlue code as did WannaCry

My big fear is that Banks and Financial Institution had been targeted by Petya Ransomware. If it infects a large number of Banks then we could possibly see a Major Banking Crisis. It might be an idea to keep some cash on hand, in a safe place. Because it operates as Worm Code it is hard to detect and eliminate.

I will prepare a full review later this week. In the meantime the following are links which will shed light on what is happening. Some of the protective measures which stopped WannaCry Ransomware in it’s tracks, like disabling SMB ports, could also work to stop or slow the spread of Petya Ransomware.

Click on this link to visit Krebs On Security to read their initial post about Petya.

Click on this link to visit the Kaspersky Lab post titled “Petya Ransomware eats your hard drives“

Click on this link to visit the Securelist site to read their very detailed post about how Petya Ransomware functions.

Click on this link to visit the Check Point site to read their discussion of the Petya Ransomware worldwide outbreak.

Video is courtesy of the F-Secure YouTube channel

 Click on this link to view the prior coverage about WannaCry Ransomware found on Uniquely Toronto.

Posted by Vincent Banial

Analysis of PETYA Ransomware running live on a computer

Petya Ransomware could be called WannaCry V3 as it is using the same EternalBlue / DoublePulsar code. It starts running via a Windows DLL. In the video below Colin runs Petya on a computer to be able to study it.

Video is courtesy of the Colin Hardy YouTube channel