Remove MW_ IN FILES.txt or KK_ IN YOUR DOCUMENTS.txt virus (Guide)

If your pictures, videos and documents have an MW_ or KK_ prefix at the end and have a MW_ IN FILES.txt or KK_ IN YOUR DOCUMENTS.txt document on your desktop, then your computer has been infected with the Trojan-Ransom.NSIS.ONION.air ransomware.

Trojan-Ransom.NSIS.ONION.air is a file-encrypting ransomware, which will encrypt the personal documents found on victim’s computer using RSA-2048 key (AES CBC 256-bit encryption algorithm). Trojan-Ransom.NSIS.ONION.air then displays a message which offers to decrypt the data if a payment of 1 BTC (Bitcoins) is made within 96 hours, otherwise the data will be destroyed.



1. How did the MW_ or KK_ prefix virus got on my computer?
2. What is MW_ or KK_ prefix Ransomware?
3. Is my computer infected with MW_ or KK_ prefix virus?
4. Is it possible to decrypt files encrypted by MW_ or KK_ prefix?

1. How did the MW_ or KK_ prefixvirus got on my computer?

The MW_ or KK_ ransomware is distributed through several means. Malicious websites, or legitimate websites that have been hacked, can infect your machine through exploit kits that use vulnerabilities on your computer to install this Trojan without your permission of knowledge.
Another method used to propagate this type of malware is spam email containing infected attachments or links to malicious websites. Cyber-criminals spam out an email, with forged header information, tricking you into believing that it is from a shipping company like DHL or FedEx. The email tells you that they tried to deliver a package to you, but failed for some reason. Sometimes the emails claim to be notifications of a shipment you have made. Either way, you can’t resist being curious as to what the email is referring to – and open the attached file (or click on a link embedded inside the email). And with that, your computer is infected with the MW_ or KK_ (Trojan-Ransom.NSIS.ONION.air) ransowmare
The threat may also be downloaded manually by tricking the user into thinking they are installing a useful piece of software, for instance a bogus update for Adobe Flash Player or another piece of software.

2. What is MW_ or KK_ prefix Ransomware?

The MW_ or KK_ prefix is part of the Trojan-Ransom.NSIS.ONION.air ransomware program which targets all versions of Windows including Windows XP, Windows Vista, Windows 7, and Windows 8. This infection is notable due to how it encrypts the user’s files – namely, it uses AES-265 and RSA encryption method – in order to ensure that the affected user has no choice but to purchase the private key.
When MW_ or KK_ prefix ransomware is first installed on your computer it will create a random named executable in the %AppData% or %LocalAppData% folder. This executable will be launched and begin to scan all the drive letters on your computer for data files to encrypt.
Trojan-Ransom.NSIS.ONION.air ransomware searches for files with certain file prefixs to encrypt. The files it encrypts include important productivity documents and files such as .doc, .docx, .xls, .pdf, among others. When these files are detected, this infection will append a new MW_ or KK_ prefix to the file name.
Files targeted are those commonly found on most PCs today; a list of file prefixs for targeted files include:
.sql, .mp4, .7z, .rar, .m4a, .wma, .avi, .wmv, .csv, .d3dbsp, .zip, .sie, .sum, .ibank, .t13, .t12, .qdf, .gdb, .tax, .pkpass, .bc6, .bc7, .bkp, .qic, .bkf, .sidn, .sidd, .mddata, .itl, .itdb, .icxs, .hvpl, .hplg, .hkdb, .mdbackup, .syncdb, .gho, .cas, .svg, .map, .wmo, .itm, .sb, .fos, .mov, .vdf, .ztmp, .sis, .sid, .ncf, .menu, .layout, .dmp, .blob, .esm, .vcf, .vtf, .dazip, .fpk, .mlx, .kf, .iwd, .vpk, .tor, .psk, .rim, .w3x, .fsh, .ntl, .arch00, .lvl, .snx, .cfr, .ff, .vpp_pc, .lrf, .m2, .mcmeta, .vfs0, .mpqge, .kdb, .db0, .dba, .rofl, .hkx, .bar, .upk, .das, .iwi, .litemod, .asset, .forge, .ltx, .bsa, .apk, .re4, .sav, .lbf, .slm, .bik, .epk, .rgss3a, .pak, .big, wallet, .wotreplay, .xxx, .desc, .py, .m3u, .flv, .js, .css, .rb, .png, .jpeg, .txt, .p7c, .p7b, .p12, .pfx, .pem, .crt, .cer, .der, .x3f, .srw, .pef, .ptx, .r3d, .rw2, .rwl, .raw, .raf, .orf, .nrw, .mrwref, .mef, .erf, .kdc, .dcr, .cr2, .crw, .bay, .sr2, .srf, .arw, .3fr, .dng, .jpe, .jpg, .cdr, .indd, .ai, .eps, .pdf, .pdd, .psd, .dbf, .mdf, .wb2, .rtf, .wpd, .dxg, .xf, .dwg, .pst, .accdb, .mdb, .pptm, .pptx, .ppt, .xlk, .xlsb, .xlsm, .xlsx, .xls, .wps, .docm, .docx, .doc, .odb, .odc, .odm, .odp, .ods, .odt
While encrypting your files, this ransomware also create a MW_ IN FILES.txt or KK_ IN YOUR DOCUMENTS.txt text file ransom note in each folder that a file has been encrypted and on the Windows desktop. The ransomware will also change your Windows desktop wallpaper to MW_ IN FILES.bmp.
Both the wallpaper and the text ransom note will contain the same information on how to access the payment site and get your files back.
When you go to the URLs listed in the ransom note you will be taken to a TOR site where you can learn how much your ransom is and how to make the payment.
The MW_ or KK_ ransomware will also hijack your .EXE prefixs so that when you launch an executable it will attempt to delete the Shadow Volume Copies that are on the affected computer. It does this because you can use shadow volume copies to restore your encrypted files. Once the infection has successfully deleted your shadow volume copies, it will restore your exe prefixs back to the Windows defaults.
When it has finished encrypting your data files it will then show the MW_ or KK_ prefix at the end of your personal documents, and a screen demanding a ransom of 0.7 BTC in order to decrypt your files. It also states that you must pay this ransom within 96 hours or the private encryption key will be destroyed on the developer’s servers.

3. Is my computer infected with MW_ or KK_ prefix virus?

If your computer is infected with the MW_ or KK_ ransomware will display a black MW_ IN FILES.bmpwallpaper that covers the entire desktop. A MW_ IN FILES.txt or KK_ IN YOUR DOCUMENTS.txt text file will be placed on your desktop. Both files contain instruction on how or recover the encrypted files.
The messages displayed by this ransomware infection can be localized depending on the user’s location, with text written in the appropriate language.
This the message that the MW_ or KK_ ransomware may display:
Good day. Your computer has been locked by ransomware, your personal files are encrypted and you have unfortunately “lost” all your pictures,
files and documents on the computer. Your important files encryption produced on this computer: videos, photos, documents, etc.
Encryption was produced using unique public key RSA-1024 generated for this computer. To decrypt files you need to obtain the private key.
All encrypted files contain MW_
Your number: [removed]
To obtain the program for this computer, which will decrypt all files, you need to pay
3 bitcoins on our bitcoin address [removed] (today 1 bitcoin was 260 USA dollars). Only we and you know about this bitcoin address.
You can check bitcoin balanse here – https://www.blockchain.info/address/[removed]
After payment send us your number on our mail ttk@ruggedinbox.com and we will send you decryption tool (you need only run it and all files will be decrypted during 1…3 hours)
Before payment you can send us one small file (100..500 kilobytes) and we will decrypt it – it’s your garantee that we have decryption tool. And send us your number with attached file
We dont know who are you. All what we need – it’s some money.
Don’t panic if we don’t answer you during 24 hours. It means that we didn’t received your letter (for example if you use hotmail.com or outlook.com
it can block letter, SO DON’T USE HOTMAIL.COM AND OUTLOOK.COM. You need register your mail account in www. ruggedinbox .com (it will takes 1..2 minutes) and write us again)
You can use one of that bitcoin exchangers for transfering bitcoin.

4. Is it possible to decrypt files encrypted by MW_ or KK_ ransomware?

No, at this time it’s not possible.
The MW_ or KK_ ransomware is notable due to how it encrypts the user’s files – namely, it uses AES-265 and RSA encryption method – in order to ensure that the affected user has no choice but to purchase the private key. The RSA public key can only be decrypted with its corresponding private key. Since the AES key is hidden using RSA encryption and the RSA private key is not available, decrypting the files is not feasible as of this writing.
Brute forcing the decryption key is not realistic due to the length of time required to break an AES encryption key.
Unfortunately, once the MW_ or KK_ encryption of the data is complete, decryption is not feasible without paying the ransom.
Because the needed private key to unlock the encrypted file is only available through the cyber criminals, victims may be tempted to purchase it and pay the exorbitant fee. However, doing so may encourage these bad guys to continue and even expand their operations. We strongly suggest that you do not send any money to these cyber criminals, and instead adress to the law enforcement agency in your country to report this attack.

News article is edited by: yakura - 11-04-2018, 13:44

Comments 5

CBD oil
CBD oil 1 February 2020 22:11
For a long time me & my friend were searching for informative blogs, but now I am on the right place guys, you have made a room in my heart!CBD oil
Massachusetts Local Guide
Massachusetts Local Guide 4 February 2020 17:55
I love significantly your own post! I look at all post is great. I discovered your personal content using bing search. Discover my webpage is a great one as you.I work to create several content this post. Once more you can thank you and keep it create! Enjoy!Massachusetts Local Guide
Anus Ak
Anus Ak 12 February 2020 18:42
Thanks  for another wonderful post. Where else could anybody get that type of info in such an ideal way of writing? india visa for greek citizens
Anus Ak
Anus Ak 14 February 2020 14:07
I am jovial you take pride in what you write.  It makes you stand way out from many other writers that can not push high-quality content like you. avalon bitcoin miners
inspire
inspire 21 February 2020 23:52

I'm impressed, I must say. Very rarely do I come across a blog thats both informative and entertaining, and let me tell you, you ve hit the nail on the head. Your blog is important.. inspire
Add comment

Add comment

reload, if the code cannot be seen