Experts recover data encrypted by Petya ransomware
Get your data back without paying criminals


Victims of ransomware that has infected machines and prevented access to data may now be able to regain access to those files, thanks to an unidentified developer that managed to crack the malware.
The programmer, who is only known by their Twitter handle Leo_and_Stone, released the tool via code-sharing site Github. They developed the code to help their father-in-law, who's machine was infected by the malware.
The malware, which has been in circulation since March, locks up data and demands a ransom of 0.9 bitcoins (264). It arrives hidden in emails purporting to come from people looking for employment.
The malware replaces the hard drive's legitimate Mast Boot Record code. It encrypts the master file table (MFT) and display a ransom note.
What is novel about this malware is that the files are not encrypted. It is the MFT that has been changed so the operating system cannot locate data. Data recovery tools can reconstruct files, but this is not always successful.
The code developed by Leo_and_Stone means that data recovery or paying a ransom is no longer necessary. Experts from BleepingComputer.com confirmed that the method works, but it entails extracting some data from an affected hard drive.
Tim Stiller, senior systems engineer at Rapid7, told IT Pro that what is unique about Petya ransomware and this new decryption tool is the ability to recover files without paying bitcoins.
Get the ITPro daily newsletter
Sign up today and you will receive a free copy of our Future Focus 2025 report - the leading guidance on AI, cybersecurity and other IT challenges as per 700+ senior executives
"Many ransomware variants go to great lengths to thwart the user from decrypting the files without paying the ransom. In Petya's case, the disk was encrypted with just a single key. While the description technique for decryption can be a bit complex for some, it works," he said.
"For victims infected with Petya, this tool is very helpful at recovering their data. From the malware author's perspective, this particular decryption tool will likely prompt them to either change how the encryption functions, or shift over to a file-by-file level encryption, thus patching the ability to recover data.
"For organisations dealing with threats such as this, it is recommended that they maintain recent backups of their data and avoid opening any emails and attachments that they are unsure about. If they have any concerns, they should forward suspect emails to the security team for triage," he added.
Rene Millman is a freelance writer and broadcaster who covers cybersecurity, AI, IoT, and the cloud. He also works as a contributing analyst at GigaOm and has previously worked as an analyst for Gartner covering the infrastructure market. He has made numerous television appearances to give his views and expertise on technology trends and companies that affect and shape our lives. You can follow Rene Millman on Twitter.
-
Bigger salaries, more burnout: Is the CISO role in crisis?
In-depth CISOs are more stressed than ever before – but why is this and what can be done?
By Kate O'Flaherty Published
-
Cheap cyber crime kits can be bought on the dark web for less than $25
News Research from NordVPN shows phishing kits are now widely available on the dark web and via messaging apps like Telegram, and are often selling for less than $25.
By Emma Woollacott Published
-
‘Phishing kits are a force multiplier': Cheap cyber crime kits can be bought on the dark web for less than $25 – and experts warn it’s lowering the barrier of entry for amateur hackers
News Research from NordVPN shows phishing kits are now widely available on the dark web and via messaging apps like Telegram, and are often selling for less than $25.
By Emma Woollacott Published
-
Healthcare systems are rife with exploits — and ransomware gangs have noticed
News Nearly nine-in-ten healthcare organizations have medical devices that are vulnerable to exploits, and ransomware groups are taking notice.
By Nicole Kobie Published
-
Alleged LockBit developer extradited to the US
News A Russian-Israeli man has been extradited to the US amid accusations of being a key LockBit ransomware developer.
By Emma Woollacott Published
-
February was the worst month on record for ransomware attacks – and one threat group had a field day
News February 2025 was the worst month on record for the number of ransomware attacks, according to new research from Bitdefender.
By Emma Woollacott Published
-
CISA issues warning over Medusa ransomware after 300 victims from critical sectors impacted
News The Medusa ransomware as a Service operation compromised twice as many organizations at the start of 2025 compared to 2024
By Solomon Klappholz Published
-
Warning issued over prolific 'Ghost' ransomware group
News The Ghost ransomware group is known to act fast and exploit vulnerabilities in public-facing appliances
By Solomon Klappholz Published
-
The Zservers takedown is another big win for law enforcement
News LockBit has been dealt another blow by law enforcement after Dutch police took 127 of its servers offline
By Solomon Klappholz Published
-
There’s a new ransomware player on the scene: the ‘BlackLock’ group has become one of the most prolific operators in the cyber crime industry – and researchers warn it’s only going to get worse for potential victims
News Security experts have warned the BlackLock group could become the most active ransomware operator in 2025
By Solomon Klappholz Published