Aabn Virus Ransomware (.aabn File) Removal

What is Aabn ransomware?

A Aabn ransomware attack is undeniably distressing. It encrypts your files and demands a ransom in Bitcoins, typically around $1000. The primary objective of the cybercriminals spreading this malware is money laundering; they are not interested in personal information or other sensitive data.

The encryption used by this virus is currently unbreakable. The challenge in decryption stems not only from the encryption method itself but also because the decryption keys are securely stored on a remote server under the control of the perpetrators. The sheer number of possible keys (2*10^78) renders brute force or any similar decryption attempts futile.

In addition to encryption, Aabn malware implements changes to several crucial system settings, complicating the search for a decryption method. It blocks the execution of installation files and restricts access to anti-malware resources online. Other alterations to system settings further degrade the usability of your PC.

Understanding how the infection occurred is vital for preventing future incidents. This virus typically proliferates via websites offering "free" versions of popular software. While downloading a pirated version of Photoshop might seem harmless, there's no guarantee that the software hasn't been tampered with to include malicious code.

Encryption process

The Aabn ransomware 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 - ".aabn". 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 Aabn 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.

Ransom note: _readme.txt

Ransom note is the same for the whole ransomware 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:

External Links:

🔗 HowToFix.Guide: How To Decrypt .aabn Files?

Indicators of Compromise(IOC)

File Name	MD5	File Size
📜 SAMPLE.EXE	060abd7ab5c8a1137bc367a7375ebb5f	287744
📜 SAMPLE.EXE	3886586c358849de2ea97bd13a0dd76d	1273856
📜 SAMPLE.EXE	cca76181c58afaba8b98b16550fbbfbb	287744
📜 SAMPLE.EXE	2d819fe1bf33feeef0545e3d357880db	288256
📜 SAMPLE.EXE	75886104d568a27718a638d30dc9dac6	287232
📜 SAMPLE.EXE	6a5c1e79d2bd7a5ff8fe3c3beab0fbd6	287744
📜 SAMPLE.EXE	273eb64764ef9e68c0b7d69a6f2a79a6	279040
📜 SAMPLE.EXE	ad090ee0440cd16b750026ec61682ac3	281088
📜 SAMPLE.EXE	f457ecfcee7e34bb70327873f28bd6bc	177664
📜 SAMPLE.EXE	9dbc4eb3ea04d8c98b0a7c9c867317a6	178176