Ransomware

STOP Ransomware is a prevalent encryption virus and blackmailer, that targets valuable personal files. After infection and data encoding hackers start extorting the ransom. There have been more than 200 versions of the ransomware, each version gets slightly modified to circumvent the protection, but main footprints remain the same. The malware uses AES-256 in CFB mode. Shortly after launch, the STOP family cryptographer executable connects to C&C, retrieves the encryption key and infection ID for the victim's PC. Data is transmitted over simple HTTP in the form of JSON. If C&C is not available (the PC is not connected to the Internet, the server itself is not working), the cryptographer uses the hard-coded key and ID in it and performs offline encryption. In this case, you can decrypt the files without paying a ransom. Variations of STOP Ransomware can be distinguished from each other by ransom notes and extensions it adds to encrypted files. For STOP Ransomware under research today, extensions are: .bboo, .rooe, .repp or .alka. The ransom note file _readme.txt is presented below in the text box and picture.

Ako Ransomware is one of the fraudulent tools that is aimed to encrypt valuable files on user's computers and force them into paying a ransom. Ako Ransomware's activity was detected at the beginning of 2020 and has already been spread around Windows users. When it infiltrates your device, it raptly goes through every single folder offline consecutively restricting access to files like images, videos, PDFs, and others. Hackers use sophisticated methods to negate any interference from file decrypting tools by assigning unique cipher to each file which makes it almost impossible to decrypt them. Besides that, Ako Ransomware creates id.key file and puts it into the folder with encrypted data, that randomly changes the extension to a random set of letters and numbers, so it looks like this: 1.jpg.2mzWmb. After all, it generates the ransom note on your desktop with the necessary information to help you decrypt the files.

DCRTR-WDM Ransomware is encryption virus, endangering unprotected user's data on Windows computers. It is a successor of DCRTR Ransomware and uses the AES encryption algorithm to cipher information and demand ransom of $1270 in BTC (BitCoins). The virus was allocated to a separate subspecies in November 2018 and continued its activity in 2019 and 2020. DCRTR-WDM developers have been hiding their malware under fake "Windows Defender Monitor" updaters that can be downloaded from the web. Regrettably, once installed, it breaks all expectations because, instead of defending your PC, it instantly starts running scripts to encrypt the data stored on your computer. Currently, several generations of malware are active and distributed in the web. Besides that, frauds offer to decrypt one low-weight file that can be sent through the e-mail. This is just a trick to prove integrity and fool users into paying a ransom. However, you should never rely on their promises, because their main purpose is to deflate money and continue hunting for other victims. Unfortunately, bypassing the encryption often brings no fruits whatsoever, because developers use intricate AES-256 algorithms to encipher the data. However, with the help of our instructions, you will be able to remove it from your computer to prevent further data loss.

BitPyLock was discovered by MalwareHunterTeam and therefore categorized as ransomware. The penetration of this kind of malware leads to instant encryption to all of the files stored on your computer. BitPyLock primarily attacks photos, videos, databases and office projects which appear to be most valuable for regular users. The program uses strong military-grade encryption algorithm, RSA-4096 to be exact, thereafter changing each file extension to .bitpy. For example, 1.mp4 will be transformed into 1.mp4.bitpy which makes it impossible to open any of those. There are also other forms of this ransomware that exploit data with .domain_name or .andradegalvao extensions. BitPyLock Ransomware makes everything possible to restrict you from manual recovery by deleting backup files from the system as well. By the end of encryption, it creates an HTML note with ransom payment details.

We have already deconstructed lots of ransomware like Ouroboros, Ako, NEMTY, and others. Today, we are topping up our list with MedusaLocker Ransomware. This dreadful software is known to be encrypting the files of innocent users, therefore, making them unretrievable until a ransom is paid. Virus got its name because of the name of the project file, that says: MedusaLocker.pdb. Also, the "Medusa" section is created in the registry. Once installed on a computer, it rapidly blocks off the access to your data by assigning a unique .encrypted or .readtheinstructions or .readinstructions extensions to each file. This way, 1.jpg changes itself to 1.jpg.readtheinstructions. Unfortunately, any manipulations are useless because of the strong cipher that is hard to break manually. When encrypting files, AES encryption will be used to encrypt each file, and then the AES key will be encrypted with the RSA-2048 public key included in the Ransomware executable. Depending on ransomware edition, extensions may also look like .bomber, .boroff, .breakingbad, .locker16, .newlock, .nlocker, and .skynet as well. After successful encryption of data, extortionists add an HTML or text file, called ransom note, that contains the necessary information on how to recover your data.

GarrantyDecrypt has taken cemented position around the ransomware category and already deprived a fair amount of nerves and money of its victims. Like other ransomware, it infiltrates your computer by running encryption scripts that scan your device and therefore assign unbreakable cipher to each file. The first versions of this malware used .garrantydecrypt, .decryptgarranty, .protected, .NOSTRO, .odin, .cosanostra, .cammora, .metan, .spyhunter, .tater, .zorin extensions. However, encryption virus gets constantly modified and suffixes are changed too. Most recent extensions used by GarrantyDecrypt Ransomware are: .bigbosshorse, .heronpiston or .horsedeal. To illustrate, after encryption, 1.mp4 will be changed to 1.mp4.bigbosshorse or other abovementioned extensions. Unfortunately, any manual attempts to unlock the data are desperate. Once the encryption is finished, you will be presented with a ransom note created on desktop notifying that your data has been blocked.