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Ransom:DOS/Petya.A
Aliases: No associated aliases
Summary
Microsoft Defender Antivirus detects and removes this threat.
This ransomware can stop you from using your PC or accessing your data. It might ask you to pay money to a malicious hacker.
It may be installed by malicious documents with embedded macro, such as Trojan:O97M/Goldeneye.A.
Note: On June 27, 2017, a new variant of Ransom:Win32/Petya was observed spreading in several countries. The new variant added a worm-like capability that allows it to spread across affected networks. Read about the Petya outbreak here:
- Windows 10 platform resilience against the Petya ransomware attack
- New ransomware, old techniques: Petya adds worm capabilities
Our ransomware FAQ page has more information on this type of threat.
The trend towards increasingly sophisticated malware behavior, highlighted by the use of exploits and other attack vectors, makes older platforms so much more susceptible to ransomware attacks. From June to November 2017, Windows 7 devices were 3.4 times more likely to encounter ransomware compared to Windows 10 devices.
Read our latest report: A worthy upgrade: Next-gen security on Windows 10 proves resilient against ransomware outbreaks in 2017.
Microsoft doesn’t recommend you pay the ransom. There is no guarantee that paying the ransom will give you access to your files.
If you've already paid, see our ransomware page for help on what to do now.
Run antivirus or antimalware software
Use the following free Microsoft software to detect and remove this threat:
- Microsoft Defender Antivirus for Windows 8.1 and Windows 10, or Microsoft Security Essentials for Windows 7 and Windows Vista
- Microsoft Safety Scanner
You should also run a full scan. A full scan might find hidden malware.
Advanced troubleshooting
To restore your PC, you might need to download and run Windows Defender Offline. See our advanced troubleshooting page for more help.
You can also ask for help from other PC users at the Microsoft virus and malware community.
If you’re using Windows XP, see our Windows XP end of support page.
Use cloud protection
Use cloud protection to help guard against the latest malware threats. It’s turned on by default for Microsoft Security Essentials and Windows Defender for Windows 10.
Go to All settings > Update & security > Windows Defender and make sure that your Cloud-based Protection settings is turned On.
