There are two types of ransomware in circulation:
1) Encrypting ransomware, which incorporates advanced encryption algorithms. It’s designed to block system files and demand payment to provide the victim with the key that can decrypt the blocked content. Examples include CryptoLocker, Locky, CrytpoWall and more.
2) Locker ransomware, which locks the victim out of the operating system, making it impossible to access the desktop and any apps or files. The files are not encrypted in this case, but the attackers still ask for a ransom to unlock the infected computer. Examples include the police-themed ransomware or Winlocker.
Another version pertaining to this type is the Master Boot Record (MBR) ransomware. The MBR is the section of a PC’s hard drive which enables the operating system to boot up. When MBR ransomware strikes, the boot process can’t complete as usual, and prompts a ransom note to be displayed on the screen. Examples include Satana and Petya ransomware.
However, the most widespread type of ransomware is crypto-ransomware or encrypting ransomware, the cyber security community agrees that this is the most prominent and worrisome cyber threat of the moment.
Ransomware has some key characteristics that set it apart from other malware:
It features unbreakable encryption, which means that you can’t decrypt the files on your own
It has the ability to encrypt all kinds of files, from documents to pictures, videos, audio files and other things you may have on your PC;
It can scramble your file names, so you can’t know which data was affected. This is one of the social engineering tricks used to confuse and coerce victims into paying the ransom;
It will add a different extension to your files, to sometimes signal a specific type of ransomware strain;
It will display an image or a message that lets you know your data has been encrypted and that you have to pay a specific sum of money to get it back;
It requests payment in Bitcoins, because this crypto-currency cannot be tracked by cyber security researchers or law enforcements agencies;
Usually, the ransom payments have a time-limit, to add another level of psychological constraint to this extortion scheme. Going over the deadline typically means that the ransom will increase, but it can also mean that the data will be destroyed and lost forever.
It uses a complex set of evasion techniques to go undetected by traditional antivirus (more on this in the “Why ransomware often goes undetected by antivirus” section);
It often recruits the infected PCs into botnets, so cyber criminals can expand their infrastructure and fuel future attacks;
It can spread to other PCs connected in a local network, creating further damage;
It frequently features data exfiltration capabilities, which means that ransomware can extract data from the affected computer (usernames, passwords, email addresses, etc.) and send it to a server controlled by cyber criminals;
It sometimes includes geographical targeting, meaning the ransom note is translated into the victim’s language, to increase the chances for the ransom to be paid.
To discuss how to protect your business from Ransomware contact one of our offices to have a chat about what we can do to help, or read our Guide to protecting your business in three easy steps here.
By Simon Bell, Head of Technology