What Is “Ooops, Your important files are encrypted” - How to, Technology and PC Security Forum | SensorsTechForum.com

What Is “Ooops, Your important files are encrypted”

This article aims to explain what is “Ooops, Your important files are encrypted” ransomware and how to remove WannaCry and attempt to restore .WNCRY .WCRY or .WNCRYT files encrypted by this infection.

Update July 2017! New ransomware outbreak inspired by the WannaCry ransomware, also using “Oops your important files have been encrypted” has been detected. The virus is a modified version of Petya ransomware. More information can be found on this web link.

Threat Summary



Short DescriptionAims to encrypt the files on the compromised computer and hold them hostage for a ransom payoff of $300 in BitCoin.

SymptomsThe files on the compromised computers may be encrypted with the .WNCRY .WCRY or .WNCRYT (for temp and other files) file extensions. A ransom note, named @Please_Read_Me@.txt is dropped with instructions on what to do. The wallpaper is changed to the “Ooops, Your important files are encrypted” one.
Distribution MethodVia exploits leaked from “Lost In Translation” leak by “The Shadow Brokers” hacking group. Via botnet and worm.
Detection Tool See If Your System Has Been Affected by WannaCry


Malware Removal Tool

User ExperienceJoin our forum to Discuss WannaCry.
Data Recovery ToolWindows Data Recovery by Stellar Phoenix Notice! This product scans your drive sectors to recover lost files and it may not recover 100% of the encrypted files, but only few of them, depending on the situation and whether or not you have reformatted your drive.

Update May 2017! Malware researchers have managed to trigger multiple kill switches on the recent ransomware outbreak from the WannaCry virus which drops a ransom note, beginning with “Ooops, Your important files are encrypted”. The virus aims for one thing only – to use an AES-128 encryption in order to encrypt the important documents, videos, music and other files on the computers infected by it. One particular malware researcher, MalwareTech @MalwareTechBlog has managed to successfully locate domains that are distribution sites of the ransomware and register them in order to stop the infection process, calling it kill switch domains. However, the WannaCry ransomware continues to spread and may soon come in a new version. Read this article in case you have become a victim of this virus and wish to remove it and try to get back your files.

Update June 2017! WannaCry ransomware which is often referred to as “Ooops, Your important files are encrypted” virus appears to be active once again. It is highly possible that there are new spam campaigns distributing the ransomware. We remind you to be extra vigilant when dealing with .zip and .rar email attachments. Such emails often try to trick users into enabling macros in the attached .Word documents. However, the ransomware may also be relying on new exploits and vulnerabilities to spread itself to as many machines as possible. WannaCry a.k.a. “Ooops, Your important files are encrypted” ransomware has already taken way too many victims. Make sure to spread the word so that more users worldwide are aware of the real danger of having all their important data encrypted.

Also, keep in mind that there is another ransomware – Marlboro – using a similar ransom note and appending the .oops file extension to files. This ransomware has been decrypted.

“Ooops, Your important files are encrypted” – Infection

For it to infect a targeted computer, the WannaCry ransomware virus may take advantage of the ETERNALBLUE and DOUBLEPULSARE exploits from the leak. However, the leak revealed multiple other exploits which may be used in the infection process. These exploits are known to be the following:


In addition to this, the ransomware virus has also been reported to conducts it’s attacks via the Server Message Block protocol, also known as SMB. In order to learn how to disable all SMB activity on your computer, we recommend you to watch the following video.

In addition to this, one of the replication methods that were associated with WannaCry ransomware is via a Worm infection, meaning that the virus can automatically spread from one system to another. This is particularly dangerous, because while you are doing your daily activity, you can suddenly see the “Ooops, Your important files are encrypted” without even having to do anything. All it takes is another infected computer to spread the virus. Here is a demonstration video below by researcher Kevin Beaumont (@GossiTheDog):

“Ooops, Your important files are encrypted” – Activity

After an infection by the latest iteration of WannaCry ransomware occurs, it immediately begins to modify the computer. One of the modifications is performed with the aid of a .VBS script, also known as Visual Basic Script. It uses this script to obtain administrative permissions on the infected computer. After it has done this, the virus drops a locked .zip file on the infected computer, called wcry.zip. This file is extracted and on multiple Windows folders, the following malicious files of the malware are dropped:

  • t.wnry
  • u.wnry
  • taskse.exe
  • taskdl.exe
  • b.wnry
  • c.wnry
  • r.wnry
  • s.wnry

The malware also uses different c2 addresses to connect to TOR-based webpages in order to relay information about the infected system. In addition to this, the WannaCry ransomware grants administrative permissions in order to be able to change the wallpaper to “Ooops, Your important files are encrypted”, encrypt files and perform multiple other tasks. The command it uses to get permissions is the following:

→ icacls . /grant Everyone:F /T /C /Q

After this activity has already completed, the ransomware infection has now administrative control and it shuts down any database processes if it detects them to be present on the infected computer:

  • Mysqld.exe
  • MSExchange
  • Sqlwriter.exe
  • Sqlserver.exe
  • Microsoft.Exchange

But this is not all of the activity performed by this ransomware infection. The virus also aims to perform multiple other tasks on the infected computer, like tampering with the following Windows Registry editor keys:

HKCU\Control Panel\Desktop\Wallpaper

This Is done so that the malicious files of the WannaCry ransomware run when you start Windows and the wallpaper can be changed to the “Ooops, Your important files are encrypted” ransom message.

Q: What’s wrong with my files?

A: Ooops, your important files are encrypted. It means you will not be able to access them anymore until they are decrypted.
If you follow our instructions, we guarantee that you can decrypt all your files quickly and safely!
Let’s start decrypting!

Q: What do I do?

A: First, you need to pay service fees for the decryption.
Please send $300 worth of bitcoin to this bitcoin address: 12t9YDPgwueZ9NyMgw519p7AA8isjr6SMw

Next, please find an application file named “@WanaDecryptor@.exe”. It is the decrypt software.
Run and follow the instructions! (You may need to disable your antivirus for a while.)

Q: How can I trust?

A: Don’t worry about decryption.
We will decrypt your files surely because nobody will trust us if we cheat users.

* If you need our assistance, send a message by clicking on the decryptor window.

After this has been performed, the virus also makes sure to delete all the system restore points and shadow copies of the compromised computer:

→ vssadmin delete shadows /all /quiet
wmic shadowcopy delete
bcdedit /set boostatuspolicy ignoreallfailures
bcdedit /set {default} recoveryenabled no & wbadmin delete catalog –quiet

It’s final activity after encrypting the files is to drop it’s ransom note and open it. The file is called @WanaDecrypt0r@.exe and has a timer for the payoff:

.WNCRY .WCRY .WNCRYT Files – Encryption

The encryption process of this ransomware virus comprises of the usage of the AES (Advanced Encrytpion Standard) with a bit strength of 128. It encrypts the files on the compromised computer and then a public and private RSA-2048 key is there to make sure that the symmetric key generated from the AES encryption is encrypted and public and private key is generated from this. However, multiple RSA private keys may also be generated for each file. The cyber-criminals may be In posession of a master key that unlocks all AES RSA encrypted keys.

The files which the ransomware looks for are the following types:

→ .ldf, .sln, .suo, .cpp, .pas, .asm, .cmd, .bat, .vbs, .dip, .dch, .sch, .brd, .jsp, .php, .class, .wav, .swf, .fla, .wmv, .mpg, .vob, .mpeg, .asf, .avi, .mov, .mkv, .flv, .wma, .mid, .djvu, .svg, .psd, .nef, .tiff, .tif, .cgm, .raw, .gif, .png, .bmp, .jpg, .jpeg, .vcd, .iso, .backup, .zip, .rar, .tgz, .tar, .bak, .tbk, .PAQ, .ARC, .aes, .gpg, .vmx, .vmdk, .vdi, .sldm, .sldx, .sti, .sxi, .hwp, .snt, .onetoc2, .dwg, .pdf, .wks, .rtf, .csv, .txt, .vsdx, .vsd, .edb, .odp, .otp, .sxd, .std, .uop, .odg, .otg, .sxm, .mml, .lay, .lay6, .asc, .sqlite3, .sqlitedb, .sql, .accdb, .mdb, .dbf, .odb, .frm, .myd, .myi, .ibd, .mdf, .msg, .ost, .pst, .potm, .potx .eml, .der, .pfx, .key, .crt, .csr, .pem, .odt, .ott, .sxw, .stw, .uot, .max, .ods, .ots, .sxc, .stc, .dif, .slk, .asp, .java, .ppam, .ppsx, .ppsm, .pps, .pot, .pptm, .pptx, .ppt, .xltm, .xltx, .xlc, .xlm, .xlt, .xlw, .xlsb, .xlsm, .xlsx, .xls, .dotx, .dotm, .dot, .docm, .docb, .docx, .doc, .jar

If detected the WannaCry rasomware virus encrypts them and they may appear like the following, depending on which variant of the virus you have been infected by:

WannaCry Ransomware – Remove, Restore Files and Protect Yourself

In the event that the inevitable has happened, your first symptom of noticing this virus should be to see the icons of the ransomware on your computer. They look like the following:

If you see those files, you should IMMEDIATELY power off your computer and take out the hard drive from it to allow specialists to salvage what is left of your files without triggering the virus. In case this has already happened, we advise you to look into the instructions below to remove the ransomware. For the removal of the Wana Decrypt0r 2.0 threat, security experts outline the best method to be using an advanced anti-malware software to perform the removal automatically, especially if you lack the experience in manual removal. In order to attempt and restore encrypted files, at the moment there is no decryptor that is free and leaked out into the public, but we have multiple reports of users managing to restore chunks of their files using alternative methods. Such tools you can find in the step “2. Restore files encrypted by WannaCry” below.


Ventsislav Krastev

Ventsislav has been covering the latest malware, software and newest tech developments at SensorsTechForum for 3 years now. He started out as a network administrator. Having graduated Marketing as well, Ventsislav also has passion for discovery of new shifts and innovations in cybersecurity that become game changers. After studying Value Chain Management and then Network Administration, he found his passion within cybersecrurity and is a strong believer in basic education of every user towards online safety.

More Posts - Website

Follow Me:

Leave a Comment

Your email address will not be published. Required fields are marked *

Time limit is exhausted. Please reload CAPTCHA.

Share on Facebook Share
Share on Twitter Tweet
Share on Google Plus Share
Share on Linkedin Share
Share on Digg Share
Share on Reddit Share
Share on Stumbleupon Share