What is Ransomware and how it works?
Ransomware is a threatening malware program disguised within the target computer systems to encrypt important files and folders on it. The ransomware program uses strong encryption algorithm to encrypt files like documents, images, videos, PDF, audio and various other files of different extensions.
The encrypted files are locked with a particular extension depending upon the Ransomware threat. Thus, the files on the victim’s PC is no more accessible by any of the applications. The main purpose behind this approach is to extort money from users generally in the form of digital currency/cryptocurrency like Bitcoins.
The author of the ransomware leaves a note on the infected PC that the files have been encrypted and user needs to pay the said amount to get the decryption key. Many users and even big companies have been victimized in recent times. As the authors of the ransomware are not willing to give you any decryption key and is only an attempt to earn huge amount of money from you.
Ransomware has now became a profitable revenue channels for the malware creators and cyber criminals. Thus, they are continuously working on improving their encryption algorithm and attack sources to target bigger enterprises worldwide.
How ransomware installs on the target computer
Ransomware infections are generally attack with these following sources:
- Spam email messages with attachments contains the payload of the ransomware, which if opened installs the ransomware threat on the target computer system.
- Hacked web domain that host exploit kits generally attempts to take the advantage of vulnerabilities within the web browsers and other shady software programs to install the ransomware. For example: In recent times, WannaCrypt attacked by exploiting the Server Message Block (SMB) vulnerability CVE-2017-0144/EternalBlue. A variant of the Petya ransomware exploits the above vulnerability and along with CVE-2017-0145/EternalRomance. It further stole user credentials to further infect other computer via same network.
- Ransomware may also take the help of other nasty Trojan and malware threat to drop its payloads and further install within the computer.
Types of Ransomware threat
There are mainly four types of Ransomware that may have different point of attack and deploy methods, but all have the same motive to distort the working of the attacked computer system and demand huge amount of money as ransom to decrypt the files or unlock the screen.
Let’s take a brief of all the four types of ransomware:
File-Encrypting Ransomware:This is the most common ransomware variant that spreads with the help of spam mail attachments or other Trojans. Once infected, it targets important files and folders on the victim’s PC and encrypt them. After the encryption process is done, the files are locked with an unknown extension employed by the authors of ransomware. The ransomware leaves no option for the victims rather than paying the ransom to the authors to free their files. As it may even delete the shadow volume copies of the files. So, if the user does not have any backup of their important files then , the user may have to lose all their important data.
Screen-blocker Ransomware:This variant of ransomware rather than encrypting the files locks the entire desktop screen and the wallpaper is replaced by a ransom note that warns user of any illegal activity on their PC. The warning seems to be real as they imitate to be from any government authority like FBI, cyber authority or police.
Thus, users get scared and agrees to pay the ransom.
Browser-Locker Ransomware:This type of ransomware attacks the web browser rather than attacking the operating system. It mainly runs fake javascript codes on the infected browser which shows full page warning message showing of any childpornography, illegal internet activity so on. Its warning message is much like of screen-blocker ransomware that imitates to be any government authority.
Ransomware-as-a-service (RaaS): Ransomware-as-a-service is much i demand among the small cyber criminal groups. This is actually used as ransomware business model where the authors of the malware sell their services to other cyber offenders and hackers to carryout the ransomware attack. And the profit is shared between both the parties.
How to Restore the Encrypted Files?
If the Locker Unlock did not work, then you need to use one of the following other methods:
Method 1: Backups
Security experts always advice to keep a backup of your important files and documents. So, if have been regularly backing up your data and you can restore them after successfully removing the ransomware threat.
Method 2: File Recovery Software
If you don’t have any manual backup of your files, then you can try recover your encrypted files by using data recovery software tools. As some ransomware threat before encrypting the files make a copy of it and then delete the original ones. So, there is a possibility that file recovery software can help you recover some of your data.
Method 3: Shadow Volume Copies
If the file recovery software also does no help to you, then the last way is to try recovery process through restoring the Shadow Volume Copies. Unfortunately, many of the ransomware also deletes the shadow volume copies of the files encrypted on the attacked computer. So that the user have no way left to recover their files. But sometimes it may not be able to do so, thus, you can try this method to restore your files.
How to avoid getting infected with Ransomware?
The best to fight against any computer threat, it is be cautious while doing any kind of online activity. Here are few guidelines which will surely help you to avoid being attacked by any Ransomware threat.
The security Experts advice:
- To keep a regular backup of your important files and documents. There are now various free storage services like OneDrive, DropBox, Google Drive and other cloud storage service too.
- Always keep your firewall, anti-virus, operating system, web browsers and installed program updated.
- Never open any suspicious email and their attachments and do not download any freeware program from unknown sources.
- Keep your important files encrypted or you can even use “Controlled folder access” feature on windows 10 that prevent ransomware from encrypting your files.
