Home Ransomware Cosanostra Ransomware – Removal Tool and Prevention Guide
Cosanostra Ransomware – Removal Tool and Prevention Guide Cosanostra Ransomware – Removal Tool and Prevention Guide
Ransomware | 02/07/2019

Cosanostra Ransomware – Removal Tool and Prevention Guide

When was the last time you checked your PC health? Do you know your PC requires a regular Check Up!!!

Remove Cosanostra Ransomware from PC (+File Recovery)

The cybersecurity investigators dubbed the new variant as Cosanostra ransomware which evades the user’s system secretly and encrypts user’s valuable files and deletes system’s backup with the help of sophisticated cipher algorithm and compels you to pay the money within some time limit for the alleged restoration of your data.

Cosanostra virus belongs to one of the worst computer threat that makes entries in the Windows Registry to achieve persistence and could launch or repress processes in a Windows environment to stay concealed from the regular antivirus program and user.

If your computer has just become a victim of such an attack, you’re probably wondering how to deal with it and how to save your personal files, work documents, backup files, archives, images, videos, and many more.

However, since you are on this page, you are already a step ahead and have a chance to decrypt cosanostra ransomware before it causes more harm to the PC especially to your valuable data.

As the article advances, you will come to know how the ransomware infected your system and how to decrypt .cosanostra Ransomware files without paying the ransom, followed by various removal techniques which will help to safeguard your PC.

What is Cosanostra ransomware?

Cosanostra Ransomware is categorized as dangerous malware because the infection can have severe outcomes, and capable to infect almost all Windows Operating System version like Windows XP, Windows7, Windows8, Windows8.1 and Windows 10.

The primary purpose of the Cosanostra ransomware is to blackmail you by not allowing you to access, use or modify the personal files that you keep on your system until you pay the ransom requested by the hackers.

Instead of directly locking files, the Cosanostra ransomware changes the encrypted file names by appending .cosanostra extension.

Following strong encryption, it creates an HTML file placing a copy in every existing folder of the user’s computer.

The new HTML file contains a ransom message informing victims of the encryption and giving instructions regarding the method to pay ransom money in Bitcoin or other cryptocurrencies.

Whenever a user tries to open the compromised or locked file, it displays a ransom extortion note “cosanostra-Instruction.HTML.”

cosanostra instruction

Even if the victim contacts the developer and pays the ransom, it is tough to crack Cosanostra ransomware AES/DES cryptography technique that generates unique decryption keys, which means using any other keys does not give any positive result. Besides, they store them in remote servers and are the only ones who can access them.

It is recommended that you should never believe such cybercriminals because once payment is submitted, there is no such guarantee that you would be able to recover Encrypted files.

Also Read: What Is IDP.ALEXA.51 and How to Remove IDP.ALEXA.51 Easily

Paying money is not a good option because once you start paying a ransom, the cyber attackers will demand more.

We suggest investing the money you are demanded to pay into some backup may be a better option because data loss wouldn’t be a problem.

Further, developers of such infections via these threats steal information like IP address, URL’s Search, browser history, banking information, and ATM Card information which can lead to serious privacy violations as criminals use this data for their malicious purposes.

Thus, it is important to use a successful robust cosanostra ransomware removal tool such as Malware Crusher which will help you to remove cosanostra ransomware or other malicious content, saving you the time and struggle of hunting down various malicious files.

malware crusher

Cosanostra Ransomware – Distribution Techniques

Currently, ransomware attack campaigns may target computer users worldwide. Cosanostra ransomware distributes itself using multiple mechanisms.

A payload dropper that kick-starts the malicious script of this ransomware has been distributed around the World Wide Web, and experts have acquired a malware sample. By any chance if the file happens to be on a system and if the user clicks on it to see what kind of record it is, the system gets infected by the ransomware.

Here are some other distribution techniques which cybercriminals opt to inject malicious content in the targeted system:

  • Spam and junk attachments
  • Bundling
  • Social clickjacking
  • Pirated and free software’s
  • Torrents & P2P File Sharing
  • Fake advertisement’s or download portals, etc.

How to Prevent Cosanostra ransomware from infecting your Windows?

There have been instances in the past showing the users were hit by the same ransomware for the second time, even though they have already paid the ransom amount.

From here, all we can say is if you don’t act quickly in the right way, you might not get another chance, so we suggest you follow removal guide to delete Cosanostra ransomware that may also help you in the removal process of other malicious content. The guide is divided into two parts:

  • Unlock Computer In Safe Mode
  • Restore System

Temporarily Disable Cosanostra ransomware in safe mode using Command Prompt 

1.      Steps to be followed to enter the safe mode Win XP/Vista/7

  • Click start > then shut down > then restart.
  • While the computer is booting up at the very first screen start tapping F8 until you see the advanced boot options.
F8 safemode
  • In the advanced boot option’s, you need to select safe mode with Command prompt from the list of given options.

2.      Steps to be followed to enter safe mode in Win 8/10

  • On the windows login screen, you need to press the power option.
  • Now, press and hold the shift key on the keyboard, and then click Restart.
Windows 8 safe command
  • Now, among the list of options you need to select Troubleshoot, and then advanced options, then start-up settings and finally press restart.
  • Once your computer restarts and gives you the list of start-up options you need to select Enable Safe Mode with Command prompt. 

3.      Restore System

  • Once you see the command prompt windows, type in cd restore and hit enter on the keyboard.
  • Now, type rstrui.exe and hit Enter again.
  • Then you would see new windows, click on next over there and select a restore point that is before the date of infection.
System Restore page
  • Then, click next followed by yes.

At present, your computer is in a state that has its file and data backed up at a safe restore point. We also suggest you make a copy of backed up data into some external hard drive.

It is now time, to reinstall your Windows via an external source such as pen drive, CD or DVD.

While installing Windows, allocates disk space to C, D and E drive. If asked to restore any files, select the restore point and get the backed up data into the new operating system.

Your system format is complete; also your data is backed up. Now you must create a strong firewall against such intrusions and prevent them in the future.

Also Read: Cybersecurity Threat Faced by NASA during the Government Shutdown

Nowadays, cyber attackers have learned to make their malware more adaptable, resilient and more damaging. Common antivirus software cannot protect you from all cyber threats at the same time. 

Though, we need to comprehensively upgrade our cyber defense systems and processes to more effectively guard against cybersecurity risks, as well as to respond in a timely and robust manner to prevent any intrusion in the future.

Note* - We recommend ITL Total Security and Malware crusher, among the best reputed anti-malware software which will help you to block viruses, adware and other malware on your PC. It consists of several features to protect your system from damage and keep you safe always.

They are fully loaded with certain useful features like Real-Time Protection, Web Protection, Live updates, and many more.

malware crusher

Tips to Prevent virus and malware from Infecting Your System:
  1. Enable your popup blocker: Pop-ups and ads on the websites are the most adoptable tactic used by cybercriminals or developers with the core intention to spread malicious programs.
    So, avoid clicking uncertain sites, software offers, pop-ups etc. and Install a powerful ad- blocker for ChromeMozilla, and IE
  2. Keep your Windows Updated: To avoid such infections, we recommend that you should always keep your system updated through automatic windows update.By doing this you can keep your device free from virus.According to the survey, outdated/older versions of Windows operating system are an easy target.
  3. Third-party installation: Try to avoid freeware download websites as they usually install bundled of software with any installer or stub file.
  4. Regular Backup: Regular and periodical backup helps you to keep your data safe in case the system is infected by any kind of virus or any other infection.Thus always backup important files regularly on a cloud drive or an external hard drive.
  5. Always have an Anti-Virus: Precaution is better than cure. We recommend that you install an antivirus like ITL Total Security or a good Malware Removal Tool like Download Virus RemovalTool


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