Ransomware is a type of malicious software that blocks access to the victim’s data and threatens to publish or delete it untile a some of the money is paid. There is no guarantee that paying money can get your files back or your computer files are accessible.
You are asked to pay money because all of your computer files are encrypted and to decrypt you have to pay money. This malware has been there for while but this is the first time this has gone so big. Lots of computers have been attacked and they have infected them with the virus and encrypted all the data, in return, they have been asking for money.
Thus, ransomware is a denial-of-access attack that prevents computer users from accessing files since it is intractable to decrypt the files without the decryption key. Ransomware attacks are typically carried out using a Trojan that has a payload disguised as a legitimate file.
This has potential to attack old versions computers or that system which are using the obsolete version of Windows or software. Most vulnerable systems are Windows XP / Windows 7 and Windows 8 because Microsoft stopped providing support of Windows XP and in most of the cases Windows 7 and Windows 8 are not getting proper updates and patch files to fight with the newly released virus.
So the highest changes with getting infected with Ransome is the older system.