Last Updated: 2017-06-27 18:20:11 UTC
by Brad Duncan (Version: 1)
This is a follow-up from our previous diary about today's ransomware attacks using the new Petya variant. So far, we've noted:
- Several hundred more tweets about today's attack can be found on Twitter using #petya.
- The new Petya variant appears to be using the MS17-010 Eternal Blue exploit to propagate.
- Others claim the new variant uses WMIC to propagate
- Still no official word on the initial infection vector in today's attacks.
- People everywhere are saying today's activity is similar to last month's WannaCry ransomware attacks.
Samples of the new Petya variant are DLL files. So far, we've confirmed the following two SHA256 file hashes are the new variant:
Examining the new Petya variant
Petya is a ransomware family that works by modifying the infected Windows system's Master Boot Record (MBR). Using rundll32.exe with #1 as the DLL entry point, I was able to infect hosts in my lab with the above two DLL samples. The reboot didn't occur right away. However, when it did, my infected host did a CHKDSK after rebooting.
After CHKDSK finished, the infected Windows host's modified MBR prevented Windows from loading. Instead, the infected host displayed a ransom message.
Samples of the new Petya variant appear to have WMI command-line (WMIC) functionality. Others have confirmed this variant spreads over Windows SMB and is reportedly using the EternalBlue exploit tool, which exploits CVE-2017-0144 and was originally released by the Shadow Brokers group in April 2017. My infected Windows hosts immediately generated TCP traffic on port 445 and did ARP requests for local network hosts.
Keep in mind this is a new variant of Petya ransomware. I'm still seeing samples of the regular Petya ransomware submitted to places like VirusTotal and other locations. From what we can tell, those previous versions of Petya are not related to today's attacks.
New Petya variant ransom message
Ooops, your important files are encrypted.
If you see this text, then your files are no longer accessible, because they have been encrypted. Perhaps you are busy looking for a way to recover your files, but don't waste your time. Nobody can recover your files without our decryption service.
We guarantee that you can recover all your files safely and easily. All you need to do is submit the payment and purchase the decryption key.
Please follow the instructions:
1. Send $300 worth of Bitcoin to the following address:
2. Send your Bitcoin walled ID and personal installation key to e-mail email@example.com. Your personal installation key:
If you already purchased your key, please enter it below.
More reports about the new Petya variant
- Bleeping Computer: WannaCry Déjà Vu: Petya Ransomware Outbreak Wreaking Havoc Across the Globe
- The Hacker News: Petya Ransomware Spreading Rapidly Worldwide, Just Like WannaCry
- Reuters: Petya ransomware virus is back amid cyber attack: Swiss agency
- Palo Alto Networks Blog: Threat Brief: Petya ransomware