Ransomware

Cooper is a ransomware virus that infects systems to encrypt potentially important files and demands money for their decryption. Along with running secure encryption, it also assigns the .cooper extension to affected files. For instance, a file originally named 1.pdf will change to 1.pdf.cooper and lose its original icon. After this change, files will no longer be usable, even if you remove the added extension. To reverse these changes, decryption instructions are presented within the Cooper_Recover.txt file. Cybercriminals urge victims to contact them via e-mail and pay for unique decryption software. Threat actors are the only figures who have access to it, and it is said no other tool is able to provide decryption for enciphered .cooper files. While contacting, victims are also asked to include the ID in the subject line of an e-mail message. Unfortunately, unless you have an available backup that can be used to retrieve copies of encrypted files, paying the ransom to cyber-crooks might be the only way to return back your files. Multiple ransomware infections use strong encryption algorithms and generate online keys, ensuring decryption is barely possible without the help of initial developers.

Coza is a new ransomware sample developed by the notorious STOP/Djvu group of extortionists. Alike many other variants published by these cybercriminals, this one employs an almost identical encryption and extortion pattern. Upon settling down on an infected machine, the virus starts scanning and therefore encrypting potentially important pieces of data. By doing so, the virus aims to create more incentives for victims to pay for decryption proposed by the attackers. In addition to encryption, the malware also makes sure victims can differentiate locked from non-locked files – by simply assigning the .coza extension. For instance, a file previously named 1.xlsx will change to 1.xlsx.coza, 1.pdf to 1.pdf.coza and so forth with other targeted file types. To undo the encryption, victims are said to follow instructions within the _readme.txt text note.

Pwpdvl is a ransomware virus designed to extort money from victims by running encryption of data. In other words, people affected by this malware will no longer be able to access and view their files. When Pwpdvl enciphers potentially important files, it also assigns the victim's ID, along with the .pwpdvl extension at the end. For instance, a file like 1.pdf will alter to something like 1.pdf.[ID-9ECFA84E].pwpdvl and rest its original icon. To make victims pay money for the recovery, the file encryptor creates a ransom text note (RESTORE_FILES_INFO.txt), which contains decryption instructions. It is demanded of victims to contact the swindlers (via Bitmessage or qTOX) and pay for decryption in Monero (XMR) cryptocurrency. Before sending the payment, cybercriminals also offer to test free decryption – victims can send 2 encrypted files (non-important and 1 MB max) and get it unlocked for free. This is a kind of guarantee that extortionists offer to prove their decryption abilities and give extra confidence for paying the ransom. Though, please note that trusting cybercriminals is always a risk. Some users get fooled and do not receive the promised decryption tools/keys regardless of meeting the demands. Despite this, it is unfortunately only ransomware developers who hold the necessary decryption keys for safely restoring access to data. Independent decryption using third-party tools or Windows shadow copies can be possible but in very rare cases when ransomware contains flaws or did not manage to encrypt the data as intended.

VapeV7 is a ransomware virus designed to encrypt data across successfully infected systems. By doing so, the virus makes sure users are no longer able to access/view their own data, which enables threat actors to demand money for its decryption. The encrypted files will appear with the new .VapeV7 extension and reset their original icons to blank. After this, victims will be presented with decryption instructions in a dedicated pop-up window. In order to restore access to data, victims are demanded to send $200 to the cybercriminals' BTC wallet (via an address inside the pop-up window) and notify the extortionists with the transaction ID by e-mail. Note that BTC wallets and contact e-mails are changing each second creating a lot of uncertainty as to what wallet address and e-mail to use. Also, displayed BTC wallets are actually incorrect and thus non-existent at all. Such a strange phenomenon could be a sign that VapeV7 Ransomware is bugged or still under development. However, not excluded that cybercriminals behind this ransomware will remove the bugs and strike future victims with more reliable decryption guidelines. Unfortunately, despite this fact, files enciphered by VapeV7 Ransomware are less likely to be decryptable manually.

Charmant is a malicious program that falls under the category of ransomware. Malware of such is designed to encrypt access to data and make victims pay money for its decryption. While enciphering access to system-stored files, this ransomware variant also assigns the .charmant extension to highlight the blocked data. For instance, a file like 1.pdf will change to 1.pdf and lose its original icon. Immediately after the encryption is finished, a text note named #RECOVERY#.txt gets created to feature decryption guidelines. To establish contact with cybercriminals and request the decryption of locked files, victims are instructed to write via e-mail or Jabber client (a secure messaging service). Following successful communication with cybercriminals, victims will most likely be demanded to pay a certain ransom fee to obtain special software and a decryption key. In addition, the message also warns against running any modifications to files or trying to decrypt them using third-party tools because such actions may lead to permanent damage. While this information may be initially designed to scare inexperienced users and eventually pay for decryption, it is actually true. Without the right decryption keys that are stored by cybercriminals, it is rarely possible to decrypt files fully and without damage risks. At the moment of writing this article, no third-party tool is known to be able to decrypt the locked data. In rare cases, generic decryption tools may work only if ransomware contained flaws or did not manage to encrypt the files in the intended way.

Recently, experts have observed the epidemic of the virus Boty Ransomware (a variant of STOP Ransomware or Djvu Ransomware). This malware appeared in April 2023. It is an encryption virus, that uses a strong AES-256 encryption algorithm to encrypt user files and makes them unavailable for use without a decryption key. Latest versions of this pest add .boty extensions to affected files. Boty Ransomware creates a special text file, that is called "ransom note" and named _readme.txt. In this text file, malefactors provide contact details, overall information about encryption, and options for decryption. The virus copies it on the desktop and in the folders with encrypted files. Malefactors can be contacted via e-mails: support@freshmail.top and datarestorehelp@airmail.cc.

Boza Ransomware is a new variant of the STOP/Djvu Ransomware that emerged in early April 2023. This ransomware adds the .boza extension to the encrypted files, making them inaccessible to the user. Like other ransomware variants, Boza Ransomware uses advanced encryption algorithms to lock files, demanding a ransom in exchange for the decryption key. The ransomware targets a wide range of files, including documents, images, videos, audios, and other user data. Once the ransomware infects a computer, it scans the entire system for files and encrypts them using the AES-256 encryption algorithm, making them inaccessible. The ransomware also drops a ransom note called _readme.txt, providing instructions for the user to pay the ransom to the attacker in exchange for the decryption key. The attackers also use a unique encryption key for each infected system, making it difficult for security researchers to develop a universal decryption tool.

Kiop Ransomware is another representative of STOP/Djvu virus, that has been tormenting users since 2017. This particular version was released in the beginning of April 2023 and adds .kiop extension to all encrypted files, as can be seen from its name. Other than that, it's the same file-encypting and ransom-demanding virus as hundreds of its predecessors. Ransomware of this type uses the same cryptography, that is, unfortunately, still undecryptable. Kiop Ransomware, like other variants of STOP/Djvu Ransomware, typically uses a combination of symmetric and asymmetric encryption algorithms to encrypt the victim's files. Specifically, the ransomware uses AES-256 encryption to encrypt the victim's files symmetrically, and then uses RSA-2048 encryption to encrypt the AES encryption key asymmetrically. This means that the attacker holds the private RSA key needed to decrypt the AES encryption key, and therefore can decrypt the victim's files after receiving payment.The only things that change during last years are extension and contact e-mail addresses. The name of the ransom note remains unchanged (_readme.txt) and you can check the content in the text box below.