What is Kruu virus?
Kruu virus is a new ransomware that attacks the victim’s computer by encrypting files and demanding a ransom for decrypting them. The ransomware attack can lead to data loss and financial losses. Kruu encrypts files, renames them by appending the .kruu extension, and creates files named “_readme.txt” containing the ransom demand message. For example, a file named “document.docx” will be renamed to “document.docx.kruu”, a “image.jpg” file to “image.jpg.kruu”, “invoice.pdf” to “invoice.pdf.kruu”, and so on.
- What is Kruu virus?
- Remove Kruu virus (ransomware)
- Decrypt .kruu files
- Restore .kruu files
- Video Guide
Kruu ransomware is a new malware that belongs to the STOP ransomware family. It encrypts files using a strong encryption algorithm. The virus uses a long key to encrypt files. This key is unique for each victim, therefore it excludes the possibility of using the same key to decrypt files on different computers. In some cases, when the virus cannot establish a connection to its command server (C&C), it uses the so-called ‘offline key’. This key is the same for all victims. And most importantly, the security researchers have found a way to determine this key.
Kruu does not encrypt absolutely all files, as it will cause the computer to stop working. Therefore, it skips and does not encrypt Windows system files as well as files with the name ‘_readme.txt’. All other files on the victim’s computer will be encrypted. It makes no difference where the files are located, on a hard drive or cloud storage. If at the time of the ransomware attack a disk was connected to the computer, then all the files on it can be encrypted. In addition to the fact that Kruu virus does not matter where the files are located, it also does not matter what type of files they are. Files of all common types can be encrypted, including the following:
.itl, .3fr, .mov, .apk, .xld, .wbz, .hvpl, .p7b, .iwd, .rtf, .epk, .tax, .dba, .ncf, .sav, .wsd, .wn, .xll, .das, .kf, .zdc, .xyw, .yml, .odb, .xar, .x3d, .esm, .vtf, .erf, .pfx, .re4, .0, .ods, .xdl, .bc7, .xpm, .hplg, .docm, .wdb, .snx, .zabw, .pdf, .rw2, .fsh, .lvl, .menu, .eps, .wpe, .dcr, .wdp, .sis, .txt, .p12, .7z, .wpb, .png, .qic, .1st, .vpp_pc, .lrf, .pak, .z3d, .crw, .itm, .lbf, .wbmp, .mdb, .pef, .dng, .wp4, .wmo, .wps, .mp4, .ppt, .ff, .nrw, .xmind, .bay, .p7c, .raf, .zip, .gdb, .zif, .wbc, .webp, .zdb, .x3f, .pst, .xyp, .d3dbsp, .srw, .m3u, .xlk, .rim, .dbf, .bsa, .odp, .zi, .mddata, .wav, .wcf, .itdb, .odc, .sid, .svg, .sie, .iwi, .wp7, .xbdoc, .t12, .xml, .flv, .xlsm, .rgss3a, .sql, .xwp, .js, .wbk, .wri, .2bp, .yal, .xlgc, .sr2, .psk, .xlsm, .cdr, .xls, .docx, .cer, .xy3, .blob, .wmv, .map, .mcmeta, .odt, .layout, .pkpass, .wbd, .zip, .wsh, .wp6, .wpl, .vcf, .mpqge, .mrwref, .wotreplay, .wm, .pptm, .orf, .jpe, .doc, .wpt, .1, .zw, .mef, .icxs, .vdf, .ptx, .xdb, .jpeg, .raw, .arch00, .cr2, .fpk, .xbplate, .upk, .dmp, .wb2, .pem, .hkdb, .mdbackup, .wpw, .xls, .ibank, .xlsb, .dwg, .wsc, .xlsx, .xxx, .sb, .xx, .avi, .rofl, .m4a, .ysp, .x3f, .xlsx, .ai, .wpd, .qdf, .tor, .kdb, .ybk, .bkf, .wbm, .srf, .wma, .x, .wot, .syncdb, .cfr, .wps, .webdoc, .xf, .ws, .y, .kdc, .css, .fos, .wp, .wire, .jpg, .forge, .cas, .litemod, .wma, .wpd, .py, .wmf, .3ds, .wpg, .rb, .dazip, .xmmap, .sum, .psd, .bc6, .pdd, .t13, .dxg, .ztmp, .w3x, .bar, .db0, .csv
When the process of encrypting the victim’s files is completed, all documents, databases, pictures and other files will be encrypted and thus the contents of these files will be locked. All encrypted files will receive a new name, which consists of their old name and the extension ‘.kruu’ added to the right. This means literally the following, if the non-encrypted file had the name ‘document.docx’, then after encryption it will be called ‘document.docx.kruu’. Kruu virus places files called ‘_readme.txt’ in each folder where there is at least one encrypted file. The contents of such a file are shown in the image below.
This file contains a message from Kruu authors. They inform the victim that the files on the computer were encrypted and offer him to buy a unique key and decryptor. According to them, this is the only way to decrypt files encrypted by the ransomware and thus restore access to their contents. The criminals demand $980 from the victim, but agree to take half the amount if the victim transfers it within 72 hours. Since the attackers understand that no one trusts their words, they offer the victim to decrypt one file for free. The main requirement for this file, it should be small and not contain important information. Nevertheless, all security experts warn victims of Kruu virus; successful decryption of one file does not guarantee anything at all. There is no guarantee that payment of the ransom will become a way to decrypt the files encrypted by the ransomware.
Text presented on the Kruu ransom note:
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:
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:
Reserve e-mail address to contact us:
Your personal ID:
|Name||Kruu ransomware, Kruu file virus|
|Type||Ransomware, Crypto malware, File locker, Crypto virus, Filecoder|
|Ransom amount||$980/$490 in Bitcoins|
|Detection Names||Win32:PWSX-gen [Trj], W32.AIDetect.malware1, Win.Malware.Filerepmalware-9941437-0, Win/malicious_confidence_100% (W), Malicious (score: 100), A Variant Of Win32/Kryptik.HPOF, Trojan-Ransom.StopCrypt, UDS:Trojan-Ransom.Win32.Stop.gen, Trojan.Win32.SmartFortress.lEDV, Trojan.MalPack.GS, BehavesLike.Win32.Generic.cc, Trojan.Win32.Save.a|
|Symptoms||When you try to open your file, Windows notifies that you do not have permission to open this file. Windows Explorer displays a blank icon for the file type. Files named such as ”, ‘#_README_#’, ‘_DECRYPT_’ or ‘recover’ in each folder with at least one encrypted file.. Your desktop is locked with a message about How to pay to unlock your system.|
|Distribution ways||Malicious spam (also known as ‘malspam’). Drive-by downloads from a compromised web site. Social media posts (they can be used to trick users to download malicious software with a built-in ransomware downloader or click a suspicious link). Remote desktop protocol (RDP) hacking.|
|Removal||Kruu ransomware removal guide|
|Decryption||Kruu File Decrypt Tool|
Criminals do not lie, claiming that encrypted files cannot be decrypted without a key and decryptor. Security researchers confirm the words of the attackers said in the ransom demand message. The contents of the affected files are encrypted. But the files are not fully encrypted, but only the first 154kb of their contents. This can help the victims almost nothing, the only thing, since the files are not fully encrypted, the victim can restore files from large ZIP archives. It is enough to simply rename the encrypted file by removing the .kruu extension and open this file in the archiver, after which simply extract the desired file from the archive.
If your files have been encrypted with .kruu extension, then there is no need to despair. Fortunately, there are several ways to recover the contents of encrypted files, but before proceeding, you need to find and remove Kruu virus, so that you stop the malicious actions of the ransomware. Below you will find detailed instructions that will demonstrate you how to remove Kruu, how to use Kruu File Decrypt Tool to decrypt files, and how to recover files if the decryptor did not help you. We advise you not to skip any steps, each of the steps is very important and must be completed by you. In order not to get confused and not miss an important point in the instructions, we recommend that you print this article or open it on your smartphone.
How to remove Kruu virus (ransomware)
Before you start decrypting or recovering .kruu files, you need to remove Kruu ransomware and its autostart entries. This must be done since otherwise the ransomware may re-encrypt the restored files. You can stop the ransomware from working, as it is not difficult to do. Another option is to perform a full system scan using free malware removal tools capable of detecting and removing ransomware infection.
It is very important to scan the computer for malware, as security researchers found that spyware could be installed on the infected computer along with the Kruu ransomware. Spyware is a very dangerous security threat as it is designed to steal the user’s personal information such as passwords, logins, contact details, etc. If you have any difficulty removing the Kruu virus, then let us know in the comments, we will try to help you.
To remove Kruu virus, follow the steps below:
Kill Kruu ransomware
Press CTRL, ALT, DEL keys together.
Click Task Manager. Select the “Processes” tab, look for something suspicious that is the Kruu ransomware then right-click it and select “End Task” or “End Process” option. If your Task Manager does not open or the Windows reports “Task manager has been disabled by your administrator”, then follow the guide: How to Fix Task manager has been disabled by your administrator.
It is not difficult to detect a process related to the Kruu ransomware. When looking for a malicious process, pay attention to the process icon and its name. Most often, this ransomware has a process name in the following format: 4-characters.tmp.exe or 4-characters.exe. For example: 7533.tmp.exe, A4b1.exe, CD15.tmp.exe, 19b2.exe. The process name can also contain “(32 bit)”. If you do not find a process with a similar name in the list of processes, then most likely the Kruu ransomware has finished working. But keep in mind, if you do not remove the ransomware autostart entries, as demonstrated below, and do not delete its file, then after a while it may start again, and if it finds unencrypted files, immediately encrypt them.
Disable Kruu Start-Up
Select the “Start-Up” tab, look for something similar to the one shown in the example below, right click to it and select Disable.
Close Task Manager.
Delete Kruu Task
Type “Task Scheduler” in the search bar. Click Task Scheduler app in the search results. Click “Task Scheduler Library” in the left panel. On the right panel, right-click to “Time Trigger Task” and select Delete.
Close Task Scheduler.
Remove Kruu virus
Run Task Manager and select the “Start-Up” tab. Right click to the Kruu Start-Up entry and select Open File Location as shown below.
A directory containing one file will open in front of you, this file is the Kruu virus. It needs to be removed. If you try to delete it immediately, then you will not succeed, since this file is protected from deletion.
To delete this file, you need to do the following. Right-click on the file, select Properties. In the window that opens, select Security tab. Next, click the Advanced button below. A window will open as shown in the following example.
Click Disable inheritance. In the Block inheritance dialog box that opens, select the first item (Convert inherited permissions…) as shown below.
In the Permission entries list, select “Deny Everyone”, click Remove button and then OK. Close the file properties window. You should now be able to remove the Kruu virus. Right-click on the file and select Delete.
Scan computer for malware
MalwareBytes is a malware removal tool that can be used to remove spyware, trojans, worms, adware, malware, ransomware and other security threats. This program is one of the most efficient anti-malware tools. It helps in ransomware removal and and defends all other types of malware. One of the biggest advantages of using MalwareBytes Anti Malware is that is easy to use and is free. Also, it constantly keeps updating its virus/malware signatures DB. Let’s see how to install and scan your computer with MalwareBytes in order to remove Kruu ransomware from the computer.
Installing the MalwareBytes is simple. First you’ll need to download it from the following link. Save it to your Desktop.
Category: Security tools
Update: April 15, 2020
When the download is complete, close all apps and windows on your device. Open a directory in which you saved it. Double-click on the icon that’s called MBSetup as displayed in the following example.
When the installation begins, you will see the Setup wizard which will help you setup Malwarebytes on your computer.
Once the installation is done, you will see window similar to the one below.
Now click the “Scan” button to look for the Kruu ransomware, other malware, worms and trojans. This process can take some time, so please be patient. When a threat is detected, the number of the security threats will change accordingly.
When the scan is done, MalwareBytes Anti-Malware will open a list of found items. Review the report and then click “Quarantine” button.
Malwarebytes will now move the selected threats to the program’s quarantine. Once disinfection is complete, you may be prompted to reboot your computer.
In order to be 100% sure that the computer no longer has the Kruu ransomware, we recommend using the Kaspersky virus removal tool (KVRT). It is a free portable program that scans your computer for spyware, ransomware, adware, potentially unwanted programs, trojans, worms, malicious software and helps uninstall them easily. Moreover, it’ll also allow you uninstall any other security threats for free.
Download Kaspersky virus removal tool on your PC by clicking on the following link.
Author: Kaspersky® lab
Category: Security tools
Update: March 5, 2018
After the downloading process is done, double-click on the KVRT icon. Once initialization procedure is done, you will see the KVRT screen as displayed on the image below.
Click Change Parameters and set a check near all your drives. Click OK to close the Parameters window. Next press Start scan button to scan for Kruu virus and other known infections. When a threat is detected, the count of the security threats will change accordingly.
Once the scanning is complete, KVRT will display a screen that contains a list of malware that has been detected such as the one below.
Review the report and then click on Continue to start a cleaning task.
How to decrypt .kruu files
Files with the extension ‘.kruu’ are encrypted files. To decrypt .kruu files, you need to use a decryptor and a unique key. Fortunately, there is a free Kruu File decrypt Tool that can decrypt the encrypted files. Kruu File Decrypt Tool is compatible with all modern versions of the Windows OS and can decrypt files regardless of their size and type.
To decrypt .kruu files, use Kruu File decrypt Tool
- Download Kruu File Decrypt Tool from the following link.
STOP Djvu decryptor
- Scroll down to ‘New Djvu ransomware’ section.
- Click the download link and save the decrypt_STOPDjvu.exe file to your desktop.
- Run decrypt_STOPDjvu.exe, read the license terms and instructions.
- On the ‘Decryptor’ tab, using the ‘Add a folder’ button, add the directory or disk where the encrypted files are located.
- Click the ‘Decrypt’ button.
Kruu File Decrypt Tool is a free tool that allows everyone to decrypt .kruu files for free. As we said above, the Kruu ransomware can use two types of keys to encrypt files: online keys and offline keys. Emsisoft found a way to obtain offline keys, so at the moment the Kruu File decrypt Tool can only decrypt files encrypted with offline keys. If the files are encrypted with an online key, then they cannot be decrypted yet, since only the authors of the ransomware have the encryption key.
This does not mean that if your files are encrypted with an online key, then their contents are lost forever. Fortunately, there are several ways to recover encrypted files. These methods do not involve the use of decryption and therefore can be used in any case, regardless of what type of key the files were encrypted.
How to find out which key was used to encrypt files
Below we show two ways to help you determine what type of key was used to encrypt your files. This is very important, since the type of key determines whether it is possible to decrypt .kruu files. We recommend using the second method, as it is more accurate.
Find out the type of key using ‘_readme.txt’ file
- Open the ransom demand message (‘_readme.txt’ file).
- Scroll down to the end of the file.
- There you will see a line with the text ‘Your personal ID’.
- Below is a line of characters – this is your personal id.
Find out the type of key using ‘PersonalID.txt’ file
- Open disk C.
- Open directory ‘SystemID’.
- Open file named ‘PersonalID.txt’. This file lists ‘Personal ID’s that match the keys that the Kruu virus used to encrypt files.
The ‘Personal ID’ is not a key, it is an identifier related to a key that was used to encrypt files. If the ID ends with ‘t1’, then the files are encrypted with an offline key. If the ID does not end with ‘t1’, Kruu ransomware virus used an online key. If you could not figure out how to determine which key was used to encrypt files, then we can help. Just write a request here or in the comments below.
Kruu File Decrypt Tool : “No key for New Variant online ID”
If, when you try to decrypt .kruu files, Kruu File Decrypt Tool reports:
No key for New Variant online ID: *
Notice: this ID appears to be an online ID, decryption is impossible
It means that your files are encrypted with an ‘online key’ and their decryption is impossible, since only the boop authors have the key necessary for decryption. In this case, you need to use alternative methods listed below to restore the contents of encrypted files.
Kruu File Decrypt Tool : “No key for New Variant offline ID”
If, during decryption of .kruu files, Kruu File Decrypt Tool reports:
No key for New Variant offline ID: *t1
Notice: this ID appears be an offline ID, decryption MAY be possible in the future.
It means the following: your files are encrypted with an ‘offline key’, but the key itself has not yet been obtained by security researchers, in this case, you need to be patient and wait a while, in addition, you can also use alternative ways for recovering encrypted data.
If for some reason you were unable to decrypt the encrypted files, then We recommend to follow the news on our Facebook or YouTube channels. So you ‘ll know right away that it ‘s possible to decrypt .kruu files.
This video step-by-step guide will demonstrate How to remove Kruu virus, Decrypt/Recover .kruu files.
How to restore .kruu files
Fortunately, there are some alternative methods to recover encrypted files. Each of these methods does not require the use of a decryptor and a key, so these methods are suitable for every victim of the ransomware, regardless of the key used to encrypt the files. In addition, the use of these methods will not affect in any way the decryption of files using a free decoder. The only thing is that before you proceed with file recovery, be sure to check your computer for malware using free malware removal tools, you need to be 100% sure that the ransomware has been completely removed.
Use shadow copies to restore .kruu files
A free utility called ShadowExplorer is a simple way to use the ‘Previous Versions’ feature of Microsoft Windows 10 (8, 7 , Vista). You can restore photos, documents and music encrypted by the Kruu crypto malware from Shadow Copies for free.
ShadowExplorer can be downloaded from the following link. Save it directly to your Windows Desktop.
Category: Security tools
Update: September 15, 2019
When the download is complete, extract the downloaded file to a folder on your device. This will create the necessary files like below.
Launch the ShadowExplorerPortable program. Now select a drive (1) and a date (2) as displayed in the following example.
On right panel navigate to the file (folder) you wish to restore. Right-click to the file or folder and click the Export button as on the image below.
And finally, specify a folder (your Desktop) to save the shadow copy of encrypted file and click ‘OK’ button.
This video step-by-step guide will demonstrate How to recover encrypted files using Shadow Explorer.
Use PhotoRec to recover .kruu files
The last chance to restore encrypted files to their original state is using data recovery tools. We recommend a free tool called PhotoRec. It has all the necessary functions to restore the contents of encrypted files. It helped many victims recover data when it seemed like there was no more hope.
Download PhotoRec by clicking on the following link. Save it on your MS Windows desktop or in any other place.
Category: Security tools
Update: March 1, 2018
After downloading is complete, open a directory in which you saved it. Right click to testdisk-7.0.win and choose Extract all. Follow the prompts. Next please open the testdisk-7.0 folder as displayed below.
Double click on qphotorec_win to run PhotoRec for MS Windows. It will display a screen as displayed on the image below.
Choose a drive to recover as on the image below.
You will see a list of available partitions. Choose a partition that holds encrypted files as shown on the image below.
Press File Formats button and specify file types to restore. You can to enable or disable the restore of certain file types. When this is done, click OK button.
Next, press Browse button to select where restored files should be written, then press Search. We strongly recommend that you save the recovered files to an external drive.
Count of recovered files is updated in real time. All recovered photos, documents and music are written in a folder that you have selected on the previous step. You can to access the files even if the recovery process is not finished.
When the recovery is finished, press on Quit button. Next, open the directory where recovered photos, documents and music are stored. You will see a contents as displayed in the figure below.
All recovered photos, documents and music are written in recup_dir.1, recup_dir.2 … sub-directories. If you’re looking for a specific file, then you can to sort your restored files by extension and/or date/time.
This video step-by-step guide will demonstrate How to recover encrypted files using PhotoRec.
How to protect your PC from Kruu ransomware
Most antivirus programs already have built-in protection system against the ransomware virus. Therefore, if your system does not have an antivirus application, make sure you install it. As an extra protection, run the HitmanPro.Alert. HitmanPro.Alert is a small security tool. It can check the system integrity and alerts you when critical system functions are affected by malware. HitmanPro.Alert can detect, remove, and reverse ransomware effects.
Click the following link to download HitmanPro.Alert. Save it on your Desktop.
Category: Security tools
Update: March 6, 2019
Once downloading is complete, open the folder in which you saved it. You will see an icon like below.
Double click the HitmanPro.Alert desktop icon. After the utility is started, you will be displayed a window where you can select a level of protection, as shown in the figure below.
Now press the Install button to activate the protection.
To sum up
This guide was created to help all victims of Kruu ransomware virus. We tried to give answers to the following questions: how to remove ransomware; how to decrypt .kruu files; how to recover encrypted files; what is an online key and what is an offline key. We hope that the information presented in this manual has helped you.
If you have questions, then write to us, leaving a comment below. If you need more help with Kruu ransomware related issues, go to here.