About Tcbu:
Name | Tcbu Virus |
Version | 0606 |
File Extension | .tcbu |
Contact | [email protected], [email protected] |
Family | STOP/Djvu Ransomware |
Note | _readme.txt |
Offline ID | JBPpFMvWlKMsKlJRmPJl5e09RSnYrRJya1oX8xt1 |
Last seen | November 21, 2022 |
Algorithm | Salsa20 encryption. If Tcbu cannot establish a connection to crooks server before starting the encryption process, it uses the offline key. This key is the same for all victims(!), making it possible to decrypt .tcbu files in the future. |
Ransom | From $490 to $980 (in Bitcoins) |
Damage |
|
Distribution | Third-party downloaders, installers, peer-to-peer networks, RDP exploits, etc., |
RSA Public Key | -----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuNixGwtDpr1lo/tK0cbW NVKgJhI+1WOhfRcsXdM19vutS1xf+C8UnWpOJy8uqKxqI6I7qAx9TBtMb9V4MnqE smyH9Z2Q1RsQ7DJjWCyapEUK8Bjg3Ywe1i8hFKdWJFGsCodLT0bqpZI0bCAYwuYw SB8pSBdNfvb0L2iSS/TxEFk+6Rg9WSyTfy9FlpghWPgOtOKSx3CcT7kplM4ICh0z wh5OqPuVNY9/Hz9XuLLF18cOS5GeDWJtm0HQsVc9PpE1iK7mhKQ7rIgcSMUmLa0/ ojl5yJtL9wGHRpH0B6UxbqoRT/mlMlP1pch2pvTX9Z/EagSgBBpfVRYqN+Mcqaqj OwIDAQAB -----END PUBLIC KEY----- |
Other variants | |
What is Tcbu?
The Tcbu virus can accurately be categorized as ransomware. It encrypts your files and then demands a ransom for their release. Tcbu is part of the STOP/Djvu ransomware family, currently among the most prolific. This group predominantly preys on individuals downloading software from third-party websites.
During an attack by the Tcbu malware, your files are encrypted using the Salsa20 algorithm. This encryption technique implies approximately 2^256 possible decryption keys, equating to a 78-digit number. Regrettably, obtaining the key through brute force or other common hacking methods is practically unfeasible.
The distribution method of the Tcbu malware is critical to understand. It's established that dubious websites offering "cracked" software and unreliable tools are the main distribution channels for the entire STOP/Djvu family, and Tcbu is no exception. This ransomware is typically embedded in software presented as "free", despite being paid products on official sites. Users who bypass license verification in these programs inadvertently incorporate malware into the "final product", as virus developers compensate them for this. Similarly, questionable tools like cheat engines, Windows activators, or keygens often require disabling your antivirus software, leaving you vulnerable and likely unaware of the infection until it's too late.
Tcbu Encryption process
The Tcbu uses the Salsa20 encryption algorithm. That is not the strongest method, but it still provides an overwhelming amount of possible decryption keys. To brute force the 78-digit number of keys, you need 3.5 unvigintillion years (1*10^65), even if you use the most powerful regular PC. Quantum computers can show a bit better results, but it is still too slow to get your files back while you are alive.
The exact algorithm of encryption is next: malware scans each folder for the files it is able to encrypt. Then, when it finds the target, it makes a copy of your file, removes the original one, encrypts the copy and leaves it instead of the removed original. Such a procedure is done to prevent the situation when you have already opened the file, so ransomware is not able to read it because of the Windows restrictions. To each encrypted copy, the virus adds the specific extension - ".tcbu". Then, ransomware creates a _readme.txt file in the folder where the encrypted file is located, and goes to the next folder.
Such an encryption method can be exploited for file recovery. Since the original file is deleted, you may try to recover it using the file recovery tools. The less time is passed - the bigger the chance to get your files back, so hurry up!
Another specific moment that can help you to use the files even after the encryption is the fact that Tcbu ransomware encrypts only the first 150KB of each file. Hence, you can try to run a big file, such as video or music, without the encryption. Similar feature also works with other ransomware families - Dharma, Conti and Makop encrypt the same 150KB.
Tcbu note:
Ransom note is the same for the whole STOP/DJVU family. In fact, it is one of the main signs of to which family the certain ransomware belongs. Here is the typical note for STOP/Djvu family:
ATTENTION!
Don't worry, you can return all your files!
All your files like pictures, databases, documents and other important are encrypted with strongest encryption and unique key.
The only method of recovering files is to purchase decrypt tool and unique key for you.
This software will decrypt all your encrypted files.
What guarantees you have?
You can send one of your encrypted file from your PC and we decrypt it for free.
But we can decrypt only 1 file for free. File must not contain valuable information.
You can get and look video overview decrypt tool:
https://we.tl/t-bpYXr2m3kI
Price of private key and decrypt software is $980.
Discount 50% available if you contact us first 72 hours, that's price for you is $490.
Please note that you'll never restore your data without payment.
Check your e-mail "Spam" or "Junk" folder if you don't get answer more than 6 hours.
To get this software you need write on our e-mail:
[email protected]
Reserve e-mail address to contact us:
[email protected]
Your personal ID:
****************
External Links:
🔗 HowToFix.Guide: How To Decrypt .tcbu Files? |
Indicators of Compromise(IOC)
File Name | MD5 | File Size |
---|---|---|
📜 SAMPLE.EXE | 4fc8007cbf247e32a9aad217e54f3776 | 192512 |
📜 SAMPLE.EXE | 1beb392ee6c671e3e8dbe5bbef7354d6 | 189952 |
📜 SAMPLE.EXE | a336908834be5589784eaf236fa1b07e | 191488 |
📜 SAMPLE.EXE | 9b9720d733b5186e71abad71e927b9b5 | 189952 |
📜 SAMPLE.EXE | 85065f2610159ffb7d6c15ca27e59190 | 193024 |
📜 SAMPLE.EXE | 87ca75065dd6cabfe9461fbefbf386df | 323584 |
📜 SAMPLE.EXE | b26c34994de77a1188bcb110985f7056 | 312832 |
📜 SAMPLE.EXE | aa6cc702008759077d3c1822fd115671 | 310272 |
📜 SAMPLE.EXE | 9a5af4928a4f33ef78c8fd81fce3c32e | 309760 |
📜 SAMPLE.EXE | 3576bb82ff373abea71ab629615ea0dd | 309760 |