Before Ransomware Went Viral: Cryptovirology, Kleptography

by Milena Dimitrova | November 10, 2015 | 0 Comments

Cryptovirology, A.Young and M.Yung Black-box Cryptosystems

Traditionally, cryptography and its applications are defensive in nature, and provide privacy, authentication, and security to users (…) It can be used to mount extortion based attacks that cause loss of access to information, loss of confidentiality, and information leakage, tasks which cryptography typically prevents (…) Potential threats and attacks that rogue use of cryptography can cause when combined with rogue software (viruses, Trojan horses), and demonstrate them experimentally by presenting an implementation of a cryptovirus (…) Public-key cryptography is essential to the attacks that we demonstrate (which we call “cryptovirological attacks”). The use of cryptographic tools should be managed and audited in general purpose computing environments, and imply that access to cryptographic tools should be well controlled (…).

The quote you have just read is taken from an analysis called ‘Cryptovirology: extortion-based security threats and countermeasures’ that was presented in 1996 by the cryptovirologists Adam L.Young and Moti M. Yung. The topic was discussed during the IEEE Symposium on Security & Privacy that took place in the same year.

Cryptovirology, A.Young and M.Yung

Mr. Young and Mr. Yung are both PhD’s and it’s easy to conclude that they have dedicated their professional careers to researching and exposing cryptoviruses. As a matter of fact, Yung is the one who has coined the term cryptovirology. The term has proven to be more than precise. Why did he think of it? To emphasize on the quickly growing appliance of cryptography by computer viruses and other types of malware. He even created a secure attack from the hacker’s perspective for hijacking user data. You are correct, it sounds pretty much like ransomware. The two specialists have written many papers, few books, and have participated in a number of conferences and academic events dedicated to malicious cryptography. One of their most notable works is titled ‘Malicious Cryptography: Exposing Cryptovirology’.

Black-box Cryptosystems

As explained by the two researchers, cryptovirology depends entirely on the concept of a “black-box” cryptosystem when it comes to developing secure malware attacks against cryptosystems. A black-box cryptosystem can be perceived as both a theoretical abstraction and an everyday reality. People use black-box cryptosystems on a daily basis. For example, when you shop online, SSL (secure sockets layer) is mostly used. However, when the user doesn’t verify the implementation of SSL, SSL becomes a black-box cryptosystem.

Besides cryptovirology, another term was coined alongside cryptovirology – kleptography.

So, what is kleptography?

Let’s ‘ask’ the experts…

Kleptography as a threat has been discussed since the mid-1990s. To be more precise, Young and Yung were the first to discuss it during the 1996 Crypto conference. This is when they stressed on the multiple opportunities for attacks on the cryptography of black-box systems. As seen from today’s perspective, Young and Yung may fit right in the shoes of modern malware prophets.

Do you know what a black box is?

In science, computing, and engineering, a black box is a device, system or object which can be observed in terms of its inputs and outputs without any expertise of its internal functionalities. Its implementation is “opaque”, hence, probably, the name. Many things can be referred to as a black box: a transistor, algorithm, even the human brain.

A kleptographic attack is an attack initiated by a hacker that uses asymmetric encryption to administer a cryptographic backdoor. In such an attack, the backdoor is implemented straight within the communication. In that sense, kleptography can be grasped as a subfield of cryptovirology – as the utilization of cryptography in malicious software. It’s, however, important to note that a klepto-attack should be observed in the specific environment of a cryptosystem.

Almost 2 decades ago the experts also introduced the concept of ‘Secretly Embedded Trapdoor with Universal Protection’ (SETUP) – an attack associated with the RSA key generation.

To be continued…

References

https://www.cryptovirology.com/

https://www.infosecurity-magazine.com/

https://en.wikipedia.org/wiki/Cryptovirology

Milena Dimitrova

An inspired writer and content manager who has been with SensorsTechForum since the project started. A professional with 10+ years of experience in creating engaging content. Focused on user privacy and malware development, she strongly believes in a world where cybersecurity plays a central role. If common sense makes no sense, she will be there to take notes. Those notes may later turn into articles! Follow Milena @Milenyim

Follow Me:

Guide 1: How to Remove from Windows.
Guide 2: Get rid of on Mac OS X.
Guide 3: Remove in Google Chrome.

Guide 4: Erase from Mozilla Firefox.
Guide 5: Uninstall from Microsoft Edge.
Guide 6: Remove from Safari.
Guide 7: Eliminate from Internet Explorer.
Guide 8: Disable Push Notifications in Your Browsers.

Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer Stop Push Pop-ups

How to Remove from Windows.

Step 1: Boot Your PC In Safe Mode to isolate and remove

OFFER

Manual Removal Usually Takes Time and You Risk Damaging Your Files If Not Careful!

We Recommend To Scan Your PC with SpyHunter

Keep in mind, that SpyHunter’s scanner is only for malware detection. If SpyHunter detects malware on your PC, you will need to purchase SpyHunter's malware removal tool to remove the malware threats. Read our SpyHunter 5 review. Click on the corresponding links to check SpyHunter's EULA, Privacy Policy and Threat Assessment Criteria

1. Hold Windows key() + R

2. The "Run" Window will appear. In it, type "msconfig" and click OK.

3. Go to the "Boot" tab. There select "Safe Boot" and then click "Apply" and "OK".

Tip: Make sure to reverse those changes by unticking Safe Boot after that, because your system will always boot in Safe Boot from now on.

4. When prompted, click on "Restart" to go into Safe Mode.

5. You can recognise Safe Mode by the words written on the corners of your screen.

Step 2: Uninstall and related software from Windows

Here is a method in few easy steps that should be able to uninstall most programs. No matter if you are using Windows 10, 8, 7, Vista or XP, those steps will get the job done. Dragging the program or its folder to the recycle bin can be a very bad decision. If you do that, bits and pieces of the program are left behind, and that can lead to unstable work of your PC, errors with the file type associations and other unpleasant activities. The proper way to get a program off your computer is to Uninstall it. To do that:

1. Hold the Windows Logo Button and "R" on your keyboard. A Pop-up window will appear.

2. In the field type in "appwiz.cpl" and press ENTER.

3. This will open a window with all the programs installed on the PC. Select the program that you want to remove, and press "Uninstall"

Follow the instructions above and you will successfully uninstall most programs.

Step 3: Clean any registries, created by on your computer.

The usually targeted registries of Windows machines are the following:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce

You can access them by opening the Windows registry editor and deleting any values, created by there. This can happen by following the steps underneath:

1. Open the Run Window again, type "regedit" and click OK.

2. When you open it, you can freely navigate to the Run and RunOnce keys, whose locations are shown above.

3. You can remove the value of the virus by right-clicking on it and removing it.

Tip: To find a virus-created value, you can right-click on it and click "Modify" to see which file it is set to run. If this is the virus file location, remove the value.

IMPORTANT!
Before starting "Step 4", please boot back into Normal mode, in case you are currently in Safe Mode.
This will enable you to install and use SpyHunter 5 successfully.

Step 4: Scan for with SpyHunter Anti-Malware Tool

1. Click on the "Download" button to proceed to SpyHunter's download page.

Download

Malware Removal Tool

It is recommended to run a scan before purchasing the full version of the software to make sure that the current version of the malware can be detected by SpyHunter. Click on the corresponding links to check SpyHunter's EULA, Privacy Policy and Threat Assessment Criteria.

2. After you have installed SpyHunter, wait for it to update automatically.

3. After the update process has finished, click on the 'Malware/PC Scan' tab. A new window will appear. Click on 'Start Scan'.

4. After SpyHunter has finished scanning your PC for any files of the associated threat and found them, you can try to get them removed automatically and permanently by clicking on the 'Next' button.

If any threats have been removed, it is highly recommended to restart your PC.

Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer Stop Push Pop-ups

Get rid of from Mac OS X.

Step 1: Uninstall and remove related files and objects

OFFER

Manual Removal Usually Takes Time and You Risk Damaging Your Files If Not Careful!

We Recommend To Scan Your Mac with SpyHunter for Mac

Keep in mind, that SpyHunter for Mac needs to purchased to remove the malware threats. Click on the corresponding links to check SpyHunter’s EULA and Privacy Policy

1. Hit the ⇧+⌘+U keys to open Utilities. Another way is to click on “Go” and then click “Utilities”, like the image below shows:

2. Find Activity Monitor and double-click it:

3. In the Activity Monitor look for any suspicious processes, belonging or related to :

Tip: To quit a process completely, choose the “Force Quit” option.

4. Click on the "Go" button again, but this time select Applications. Another way is with the ⇧+⌘+A buttons.

5. In the Applications menu, look for any suspicious app or an app with a name, similar or identical to . If you find it, right-click on the app and select “Move to Trash”.

6: Select Accounts, after which click on the Login Items preference. Your Mac will then show you a list of items that start automatically when you log in. Look for any suspicious apps identical or similar to . Check the app you want to stop from running automatically and then select on the Minus (“-“) icon to hide it.

7: Remove any left-over files that might be related to this threat manually by following the sub-steps below:

Go to Finder.
In the search bar type the name of the app that you want to remove.
Above the search bar change the two drop down menus to “System Files” and “Are Included” so that you can see all of the files associated with the application you want to remove. Bear in mind that some of the files may not be related to the app so be very careful which files you delete.
If all of the files are related, hold the ⌘+A buttons to select them and then drive them to “Trash”.

In case you cannot remove via Step 1 above:

In case you cannot find the virus files and objects in your Applications or other places we have shown above, you can manually look for them in the Libraries of your Mac. But before doing this, please read the disclaimer below:

Disclaimer! If you are about to tamper with Library files on Mac, be sure to know the name of the virus file, because if you delete the wrong file, it may cause irreversible damage to your MacOS. Continue on your own responsibility!

1: Click on "Go" and Then "Go to Folder" as shown underneath:

2: Type in "/Library/LauchAgents/" and click Ok:

3: Delete all of the virus files that have similar or the same name as . If you believe there is no such file, do not delete anything.

You can repeat the same procedure with the following other Library directories:

→ ~/Library/LaunchAgents
/Library/LaunchDaemons

Tip: ~ is there on purpose, because it leads to more LaunchAgents.

Step 2: Scan for and remove files from your Mac

When you are facing problems on your Mac as a result of unwanted scripts and programs such as , the recommended way of eliminating the threat is by using an anti-malware program. SpyHunter for Mac offers advanced security features along with other modules that will improve your Mac’s security and protect it in the future.

Click the button below below to download SpyHunter for Mac and scan for :

Download

SpyHunter for Mac

Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer Stop Push Pop-ups

Remove from Google Chrome.

Step 1: Start Google Chrome and open the drop menu

Step 2: Move the cursor over "Tools" and then from the extended menu choose "Extensions"

Step 3: From the opened "Extensions" menu locate the unwanted extension and click on its "Remove" button.

Step 4: After the extension is removed, restart Google Chrome by closing it from the red "X" button at the top right corner and start it again.

Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer Stop Push Pop-ups

Erase from Mozilla Firefox.

Step 1: Start Mozilla Firefox. Open the menu window

Step 2: Select the "Add-ons" icon from the menu.

Step 3: Select the unwanted extension and click "Remove"

Step 4: After the extension is removed, restart Mozilla Firefox by closing it from the red "X" button at the top right corner and start it again.

Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer Stop Push Pop-ups

Uninstall from Microsoft Edge.

Step 1: Start Edge browser.

Step 2: Open the drop menu by clicking on the icon at the top right corner.

Step 3: From the drop menu select "Extensions".

Step 4: Choose the suspected malicious extension you want to remove and then click on the gear icon.

Step 5: Remove the malicious extension by scrolling down and then clicking on Uninstall.

Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer Stop Push Pop-ups

Remove from Safari.

Step 1: Start the Safari app.

Step 2: After hovering your mouse cursor to the top of the screen, click on the Safari text to open its drop down menu.

Step 3: From the menu, click on "Preferences".

Step 4: After that, select the 'Extensions' Tab.

Step 5: Click once on the extension you want to remove.

Step 6: Click 'Uninstall'.

A pop-up window will appear asking for confirmation to uninstall the extension. Select 'Uninstall' again, and the will be removed.

How to Reset Safari
IMPORTANT: Before resetting Safari make sure you back up all your saved passwords within the browser in case you forget them.

Start Safari and then click on the gear leaver icon.

Click the Reset Safari button and you will reset the browser.

Windows Mac OS X Google Chrome Mozilla Firefox Microsoft Edge Safari Internet Explorer Stop Push Pop-ups

Eliminate from Internet Explorer.

Step 1: Start Internet Explorer.

Step 2: Click on the gear icon labeled 'Tools' to open the drop menu and select 'Manage Add-ons'

Step 3: In the 'Manage Add-ons' window.

Step 4: Select the extension you want to remove and then click 'Disable'. A pop-up window will appear to inform you that you are about to disable the selected extension, and some more add-ons might be disabled as well. Leave all the boxes checked, and click 'Disable'.

Step 5: After the unwanted extension has been removed, restart Internet Explorer by closing it from the red 'X' button located at the top right corner and start it again.