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Petya Malware
Published: 12/16/2025
Written by: Lizzie Danielson
What is Petya Malware?
Petya is malware first identified in 2016 that overwrites a system's Master Boot Record (MBR) with a custom bootloader, then encrypts the Master File Table (MFT), rendering the device unusable until a ransom is paid. Its most infamous variant, NotPetya, surfaced in June 2017 using the same mechanism but with a critical difference: it functions as a destructive wiper disguised as ransomware rather than genuine ransomware. Windows systems are the primary target, and the malware is designed to disrupt operations at scale.
When was Petya first discovered?
Petya first emerged in March 2016, identified in a malicious email campaign. A more destructive variant, NotPetya, surfaced in June 2017, leading to global havoc. Cybersecurity firms and organizations have analyzed the malware extensively since its discovery.
Who created Petya?
The original Petya author remains unknown. NotPetya, however, has been formally attributed to Sandworm Team (GRU Unit 74455), a unit of Russia's military intelligence agency. On February 15, 2018, the White House called it "the most destructive and costly cyber-attack in history," directly attributing it to the Russian military. In October 2020, the US Department of Justice indicted six GRU Unit 74455 officers by name for the NotPetya attack (along with the 2015–2016 Ukraine grid attacks, the 2018 Olympics disruption, and other operations). The UK, Australia, Canada, and New Zealand governments issued matching attributions. This is one of the most definitively attributed nation-state cyberattacks on record — not a speculative or purely criminal one.
What does Petya target?
Petya primarily targets Windows-based systems in businesses and organizations. High-profile industries affected include healthcare, logistics, and finance, with the Ukraine being a significant early target for NotPetya campaigns.
Petya distribution method
Original 2016 Petya variants spread primarily through phishing emails with malicious attachments. NotPetya spread differently: its initial infection vector was a compromised software update for M.E.Doc, Ukrainian tax accounting software used by nearly every business operating in Ukraine. Once inside a network, NotPetya used the EternalBlue and EternalRomance SMB exploits, along with a bundled Mimikatz-based credential harvester, to move laterally and infect other systems, no phishing required for propagation
Technical analysis of Petya malware
Petya's infection process begins with the execution of its payload, encrypting the master boot record (MBR) and MFT while displaying a ransom note on reboot. Notably, NotPetya forgoes ransom collection to maximize disruption, wiping data entirely instead of truly encrypting it.
Tactics, Techniques & Procedures (TTPs)
T1486 – Data Encrypted for Impact (MBR and file encryption via 2048-bit RSA)
T1210 – Exploitation of Remote Services (EternalBlue/EternalRomance SMBv1 exploits)
T1003.001 – OS Credential Dumping: LSASS Memory (bundled Mimikatz variant)
T1021.002 – Remote Services: SMB/Windows Admin Shares (PsExec-based lateral movement)
T1078.003 – Valid Accounts: Local Accounts
T1047 – Windows Management Instrumentation
T1529 – System Shutdown/Reboot
T1036 – Masquerading (drops PsExec as dllhost.dat)
Indicators of Compromise (IoCs)
Known hashes for Petya variants
IP addresses and domain names used for command and control (C2) communication
Suspicious network activity like excessive SMB traffic
How to know if you’re infected with Petya?
Symptoms of a Petya infection include system slowdowns, abnormal reboot cycles displaying ransom notes, and the inability to access files. Unusual network behavior or failed boot sequences can also signal infection.
Petya removal instructions
For removal, disconnect the infected machine from the network immediately. Use trusted EDR tools like Huntress to safely isolate and remediate the impacted systems. Manual removal is risky and only recommended for experts due to the malware’s complexity. Given the impact of ransomware, where possible, restoring business function from trusted backups is the best guidance
Is Petya still active?
While Petya itself has seen diminished activity, its variants, including NotPetya, continue to pose risks through legacy infections and new adaptations. Organizations must remain vigilant.
Mitigation & prevention strategies
To protect against Petya and similar threats:
Regularly patch operating systems and software.
Implement multi-factor authentication (MFA).
Conduct phishing awareness training for employees.
Use 24/7 monitoring from solutions like Huntress to detect anomalies early.
Related educational articles & videos
FAQ
Petya is malware first identified in 2016 that overwrites a system's Master Boot Record (MBR) with a custom bootloader, then encrypts the Master File Table (MFT), rendering the device unusable until a ransom is paid. Its most infamous variant, NotPetya, surfaced in June 2017 using the same mechanism but with a critical difference: it functions as a destructive wiper disguised as ransomware rather than genuine ransomware. Windows systems are the primary target, and the malware is designed to disrupt operations at scale.
Petya spreads through phishing emails with malicious links or attachments. Certain variants, such as NotPetya, also exploit vulnerabilities, enabling rapid propagation across networks via outdated SMB protocols.
Neither Petya nor NotPetya are circulating as active outbreaks today. NotPetya’s 2017 campaign was effectively self-limiting — once it burned through its initial targets, it wasn’t built for long-term reuse as a live ransomware service and hasn’t resurfaced as a widespread worm since. Two things do remain relevant: unpatched systems still vulnerable to the EternalBlue exploit it used, and Sandworm Team (GRU Unit 74455), the nation-state group behind NotPetya, which remains highly active and continues running destructive attacks with different tools. Treat Petya/NotPetya less as a live threat and more as a case study in why unpatched SMB vulnerabilities and flat networks are still dangerous.
Organizations can mitigate risks by keeping systems updated, conducting regular security awareness training, and using robust EDR tools like Huntress to monitor and remediate threats in real-time.
