The virus has encrypted all dr web files. Encryptor virus: how to disinfect and decrypt files? Decrypting files after a ransomware virus
is a malicious program that, when activated, encrypts all personal files, such as documents, photos, etc. The number of such programs is very large and it is increasing every day. Only recently we have encountered dozens of ransomware variants: CryptoLocker, Crypt0l0cker, Alpha Crypt, TeslaCrypt, CoinVault, Bit Crypt, CTB-Locker, TorrentLocker, HydraCrypt, better_call_saul, crittt, .da_vinci_code, toste, fff, etc. The goal of such encryption viruses is to force users to buy, often for a large sum of money, the program and key necessary to decrypt their own files.
Of course, you can restore encrypted files simply by following the instructions that the creators of the virus leave on the infected computer. But most often, the cost of decryption is very significant, and you also need to know that some ransomware viruses encrypt files in such a way that it is simply impossible to decrypt them later. And of course, it's just annoying to pay to restore your own files.
Below we will talk in more detail about encryption viruses, how they penetrate the victim’s computer, as well as how to remove the encryption virus and restore files encrypted by it.
How does a ransomware virus penetrate a computer?
A ransomware virus is usually spread via email. The letter contains infected documents. Such letters are sent to a huge database of email addresses. The authors of this virus use misleading headers and contents of letters, trying to trick the user into opening a document attached to the letter. Some letters inform about the need to pay a bill, others offer to look at the latest price list, others offer to open a funny photo, etc. In any case, opening the attached file will result in your computer being infected with a ransomware virus.
What is a ransomware virus?
A ransomware virus is a malicious program that infects modern versions of Windows operating systems, such as Windows XP, Windows Vista, Windows 7, Windows 8, Windows 10. These viruses try to use the strongest possible encryption modes, for example RSA-2048 with the key length is 2048 bits, which practically eliminates the possibility of selecting a key to independently decrypt files.
When infecting a computer, the ransomware virus uses the system directory %APPDATA% to store its own files. To automatically launch itself when you turn on the computer, the ransomware creates an entry in the Windows registry: sections HKCU\Software\Microsoft\Windows\CurrentVersion\Run, HKCU\Software\Microsoft\Windows\CurrentVersion\RunOnce, HKCU\Software\Microsoft\Windows\CurrentVersion\ Run, HKCU\Software\Microsoft\Windows\CurrentVersion\RunOnce.
Immediately after launching, the virus scans all available drives, including network and cloud storage, to determine files that will be encrypted. A ransomware virus uses a filename extension as a way to identify a group of files that will be encrypted. Almost all types of files are encrypted, including such common ones as:
0, .1, .1st, .2bp, .3dm, .3ds, .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, .wav, .wbc, .wbd, .wbk, .wbm, .wbmp, .wbz, .wcf , .wdb, .wdp, .webdoc, .webp, .wgz, .wire, .wm, .wma, .wmd, .wmf, .wmv, .wn, .wot, .wp, .wp4, .wp5, . wp6, .wp7, .wpa, .wpb, .wpd, .wpe, .wpg, .wpl, .wps, .wpt, .wpw, .wri, .ws, .wsc, .wsd, .wsh, .x, .x3d, .x3f, .xar, .xbdoc, .xbplate, .xdb, .xdl, .xld, .xlgc, .xll, .xls, .xlsm, .xlsx, .xmind, .xml, .xmmap, .xpm , .xwp, .xx, .xy3, .xyp, .xyw, .y, .yal, .ybk, .yml, .ysp, .z, .z3d, .zabw, .zdb, .zdc, .zi, . zif, .zip, .zw
Immediately after a file is encrypted, it receives a new extension, which can often be used to identify the name or type of ransomware. Some types of these malware can also change the names of encrypted files. The virus then creates a text document with names like HELP_YOUR_FILES, README, which contains instructions for decrypting the encrypted files.
During its operation, the encryption virus tries to block the ability to restore files using the SVC (shadow copy of files) system. To do this, the virus, in command mode, calls the utility for administering shadow copies of files with a key that starts the procedure for completely deleting them. Thus, it is almost always impossible to restore files by using their shadow copies.
The ransomware virus actively uses intimidation tactics by giving the victim a link to a description of the encryption algorithm and displaying a threatening message on the Desktop. In this way, he tries to force the user of the infected computer, without hesitation, to send the computer ID to the email address of the virus’s author in order to try to get his files back. The response to such a message is most often the ransom amount and the e-wallet address.
Is my computer infected with a ransomware virus?
It is quite easy to determine whether a computer is infected with an encryption virus or not. Pay attention to the extensions of your personal files, such as documents, photos, music, etc. If the extension has changed or your personal files have disappeared, leaving behind many files with unknown names, then your computer is infected. In addition, a sign of infection is the presence of a file named HELP_YOUR_FILES or README in your directories. This file will contain instructions for decrypting the files.
If you suspect that you have opened an email infected with a ransomware virus, but there are no symptoms of infection yet, then do not turn off or restart your computer. Follow the steps described in this manual, section. I repeat once again, it is very important not to turn off the computer; in some types of ransomware, the file encryption process is activated the first time you turn on the computer after infection!
How to decrypt files encrypted with a ransomware virus?
If this disaster happens, then there is no need to panic! But you need to know that in most cases there is no free decryptor. This is due to the strong encryption algorithms used by such malware. This means that without a private key, it is almost impossible to decrypt files. Using the key selection method is also not an option, due to the large length of the key. Therefore, unfortunately, only paying the authors of the virus the entire requested amount is the only way to try to obtain the decryption key.
Of course, there is absolutely no guarantee that after payment the authors of the virus will contact you and provide the key necessary to decrypt your files. In addition, you need to understand that by paying money to virus developers, you yourself encourage them to create new viruses.
How to remove a ransomware virus?
Before you begin, you need to know that by starting to remove the virus and attempt to restore the files yourself, you are blocking the ability to decrypt the files by paying the authors of the virus the amount they requested.
Kaspersky Virus Removal Tool and Malwarebytes Anti-malware can detect different types of active ransomware viruses and will easily remove them from your computer, BUT they cannot recover encrypted files.
5.1. Remove ransomware using Kaspersky Virus Removal Tool
By default, the program is configured to recover all file types, but to speed up the work, it is recommended to leave only the file types that you need to recover. When you have completed your selection, click OK.
At the bottom of the QPhotoRec program window, find the Browse button and click it. You need to select the directory where the recovered files will be saved. It is advisable to use a disk that does not contain encrypted files that require recovery (you can use a flash drive or external drive).
To start the procedure for searching and restoring original copies of encrypted files, click the Search button. This process takes quite a long time, so be patient.
When the search is complete, click the Quit button. Now open the folder you have chosen to save the recovered files.
The folder will contain directories named recup_dir.1, recup_dir.2, recup_dir.3, etc. The more files the program finds, the more directories there will be. To find the files you need, check all directories one by one. To make it easier to find the file you need among a large number of recovered ones, use the built-in Windows search system (by file contents), and also do not forget about the function of sorting files in directories. You can select the date the file was modified as a sort option, since QPhotoRec attempts to restore this property when restoring a file.
How to prevent a ransomware virus from infecting your computer?
Most modern anti-virus programs already have a built-in protection system against the penetration and activation of encryption viruses. Therefore, if you do not have an antivirus program on your computer, be sure to install it. You can find out how to choose it by reading this.
Moreover, there are specialized protection programs. For example, this is CryptoPrevent, more details.
A few final words
By following these instructions, your computer will be cleared of the ransomware virus. If you have any questions or need help, please contact us.
The fact that the Internet is full of viruses does not surprise anyone today. Many users perceive situations related to their impact on systems or personal data, to put it mildly, turning a blind eye, but only until a ransomware virus specifically takes hold in the system. Most ordinary users do not know how to disinfect and decrypt data stored on a hard drive. Therefore, this contingent is “led” to the demands put forward by the attackers. But let's see what can be done if such a threat is detected or to prevent it from entering the system.
What is a ransomware virus?
This type of threat uses standard and non-standard file encryption algorithms that completely change their contents and block access. For example, it will be absolutely impossible to open an encrypted text file for reading or editing, as well as play multimedia content (graphics, video or audio) after exposure to the virus. Even standard actions to copy or move objects are unavailable.
The virus software itself is a tool that encrypts data in such a way that it is not always possible to restore its original state even after removing the threat from the system. Typically, such malicious programs create copies of themselves and settle very deeply in the system, so the file encrypting virus may be completely impossible to remove. By uninstalling the main program or deleting the main body of the virus, the user does not get rid of the threat, let alone restore encrypted information.
How does the threat enter the system?
As a rule, threats of this type are mostly aimed at large commercial structures and can penetrate computers through email programs when an employee opens a supposedly attached document in an email, which is, say, an addendum to some kind of cooperation agreement or product supply plan (commercial offers with investments from dubious sources are the first path for the virus).
The trouble is that a ransomware virus on a machine that has access to a local network is able to adapt to it, creating its own copies not only in the network environment, but also on the administrator terminal, if it does not have the necessary protection measures in the form of anti-virus software, firewall or firewall.
Sometimes such threats can penetrate the computer systems of ordinary users, which, by and large, are of no interest to attackers. This happens during the installation of some programs downloaded from dubious Internet resources. Many users ignore the warnings of the anti-virus protection system when starting the download, and during the installation process they do not pay attention to offers to install additional software, panels or browser plug-ins, and then, as they say, bite their elbows.
Types of viruses and a little history
In general, threats of this type, in particular the most dangerous ransomware virus No_more_ransom, are classified not only as tools for encrypting data or blocking access to it. In fact, all such malicious applications fall under the category of ransomware. In other words, attackers demand a certain bribe for decrypting information, believing that without the initial program it will be impossible to carry out this process. This is partly true.
But, if you dig into history, you will notice that one of the very first viruses of this type, although it did not demand money, was the infamous I Love You applet, which completely encrypted multimedia files (mainly music tracks) on user systems. Decrypting files after the ransomware virus turned out to be impossible at that time. Now it is precisely this threat that can be fought in an elementary way.
But the development of the viruses themselves or the encryption algorithms used does not stand still. What is there among viruses - here you have XTBL, and CBF, and Breaking_Bad, and [email protected], and a bunch of other crap.
Method of influencing user files
And if until recently most attacks were carried out using RSA-1024 algorithms based on AES encryption with the same bit depth, the same No_more_ransom ransom virus is now presented in several interpretations using encryption keys based on RSA-2048 and even RSA-3072 technologies.
Problems of deciphering the algorithms used
The trouble is that modern decryption systems were powerless in the face of such a danger. Decryption of files after an AES256-based ransomware virus is still somewhat supported, but given a higher bit depth of the key, almost all developers simply shrug their shoulders. This, by the way, has been officially confirmed by specialists from Kaspersky Lab and Eset.
In the most primitive version, the user contacting the support service is asked to send an encrypted file and its original for comparison and further operations to determine the encryption algorithm and recovery methods. But, as a rule, in most cases this does not give results. But the encrypting virus can decrypt files itself, it is believed, provided that the victim agrees to the attackers’ conditions and pays a certain amount in monetary terms. However, this formulation of the question raises legitimate doubts. And that's why.
Encryptor virus: how to disinfect and decrypt files and can it be done?
Allegedly, after payment, hackers activate decryption through remote access to their virus, which is sitting on the system, or through an additional applet if the virus body is deleted. This looks more than doubtful.
I would also like to note the fact that the Internet is full of fake posts claiming that the required amount was paid and the data was successfully restored. It's all a lie! And really - where is the guarantee that after payment the encryption virus will not be activated again in the system? It is not difficult to understand the psychology of burglars: pay once, pay again. And if we are talking about particularly important information, such as specific commercial, scientific or military developments, the owners of such information are willing to pay whatever they want to ensure that the files remain safe and sound.
The first remedy to eliminate the threat
This is the nature of an encryption virus. How to disinfect and decrypt files after exposure to a threat? No way, if there are no available means, which also do not always help. But you can try.
Let's assume that a ransomware virus has appeared in the system. How to cure infected files? First, you should perform an in-depth scan of the system without using S.M.A.R.T. technology, which detects threats only when boot sectors and system files are damaged.
It is advisable not to use an existing standard scanner, which has already missed the threat, but to use portable utilities. The best option would be to boot from Kaspersky Rescue Disk, which can start even before the operating system starts running.
But this is only half the battle, since in this way you can only get rid of the virus itself. But with a decoder it will be more difficult. But more on that later.
There is another category into which ransomware viruses fall. How to decrypt information will be discussed separately, but for now let’s focus on the fact that they can exist completely openly in the system in the form of officially installed programs and applications (the impudence of attackers knows no bounds, since the threat does not even try to disguise itself).
In this case, you should use the Programs and Features section, where standard uninstallation is performed. However, you need to pay attention to the fact that the standard uninstaller for Windows systems does not completely delete all program files. In particular, the ransom ransom virus is capable of creating its own folders in the root directories of the system (usually the Csrss directories, where the executable file of the same name csrss.exe is present). The Windows, System32 or user directories (Users on the system drive) are selected as the main location.
In addition, the No_more_ransom ransom virus writes its own keys in the registry in the form of a link, seemingly to the official Client Server Runtime Subsystem system service, which misleads many, since this service should be responsible for the interaction of client and server software. The key itself is located in the Run folder, which can be reached through the HKLM branch. It is clear that such keys will need to be deleted manually.
To make it easier, you can use utilities like iObit Uninstaller, which search for residual files and registry keys automatically (but only if the virus is visible on the system as an installed application). But this is the simplest thing you can do.
Solutions offered by antivirus software developers
Decryption of a ransomware virus, it is believed, can be done using special utilities, although if you have technologies with a 2048 or 3072 bit key, you shouldn’t really count on them (in addition, many of them delete files after decryption, and then the recovered files disappear due to the fault of the presence of a virus body that has not been removed before).
Nevertheless, you can try. Of all the programs, it is worth highlighting RectorDecryptor and ShadowExplorer. It is believed that nothing better has been created yet. But the problem may also be that when you try to use a decryptor, there is no guarantee that the files being cured will not be deleted. That is, if you do not get rid of the virus initially, any attempt at decryption will be doomed to failure.
In addition to deleting encrypted information, there can also be a fatal outcome - the entire system will be inoperable. In addition, a modern encryption virus can affect not only data stored on the computer’s hard drive, but also files in cloud storage. But there are no solutions for data recovery. In addition, as it turned out, many services take insufficiently effective protection measures (the same OneDrive built into Windows 10, which is exposed directly from the operating system).
A radical solution to the problem
As is already clear, most modern methods do not give a positive result when infected with such viruses. Of course, if you have the original of the damaged file, it can be sent for examination to an anti-virus laboratory. True, there are also very serious doubts about the fact that the average user will create backup copies of data, which, when stored on a hard drive, can also be exposed to malicious code. And the fact that in order to avoid troubles, users copy information to removable media is not discussed at all.
Thus, to radically solve the problem, the conclusion suggests itself: complete formatting of the hard drive and all logical partitions with the removal of information. So what to do? You will have to sacrifice if you do not want the virus or its self-saved copy to be activated in the system again.
To do this, you should not use the tools of Windows systems themselves (this means formatting virtual partitions, since if you try to access the system disk, a ban will be issued). It is better to boot from optical media such as LiveCD or installation distributions, such as those created using the Media Creation Tool for Windows 10.
Before starting formatting, if the virus is removed from the system, you can try to restore the integrity of system components through the command line (sfc /scannow), but this will not have any effect in terms of decrypting and unlocking data. Therefore format c: is the only correct possible solution, whether you like it or not. This is the only way to completely get rid of threats of this type. Alas, there is no other way! Even treatment with standard remedies offered by most antivirus packages turns out to be powerless.
Instead of an afterword
In terms of the obvious conclusions, we can only say that there is no single and universal solution to eliminate the consequences of this type of threat today (sad, but true - this has been confirmed by the majority of anti-virus software developers and experts in the field of cryptography).
It remains unclear why the emergence of algorithms based on 1024-, 2048- and 3072-bit encryption passed by those directly involved in the development and implementation of such technologies? Indeed, today the AES256 algorithm is considered the most promising and most secure. Notice! 256! This system, as it turns out, is no match for modern viruses. What can we say then about attempts to decrypt their keys?
Be that as it may, avoiding the introduction of a threat into the system is quite simple. In the simplest version, you should scan all incoming messages with attachments in Outlook, Thunderbird and other email clients with an antivirus immediately after receipt and under no circumstances open attachments until the scan is completed. You should also carefully read the suggestions for installing additional software when installing some programs (usually they are written in very small print or disguised as standard add-ons like updating Flash Player or something else). It is better to update multimedia components through official websites. This is the only way to at least somehow prevent such threats from penetrating into your own system. The consequences can be completely unpredictable, given that viruses of this type instantly spread on the local network. And for the company, such a turn of events can result in a real collapse of all endeavors.
Finally, the system administrator should not sit idle. It is better to exclude software protection tools in such a situation. The same firewall (firewall) should not be software, but “hardware” (naturally, with accompanying software on board). And, it goes without saying that you shouldn’t skimp on purchasing antivirus packages either. It is better to buy a licensed package rather than install primitive programs that supposedly provide real-time protection only according to the developer.
And if a threat has already penetrated the system, the sequence of actions should include removing the virus body itself, and only then attempting to decrypt the damaged data. Ideally, a full format (note, not a quick one with clearing the table of contents, but a complete one, preferably with restoration or replacement of the existing file system, boot sectors and records).
And every year more and more new ones appear... more and more interesting. The most popular virus recently (Trojan-Ransom.Win32.Rector), which encrypts all your files (*.mp3, *.doc, *.docx, *.iso, *.pdf, *.jpg, *.rar, etc. .d.). The problem is that decrypting such files is extremely difficult and time-consuming; depending on the type of encryption, decryption can take weeks, months, or even years. In my opinion, this virus is currently the apogee of danger among other viruses. It is especially dangerous for home computers/laptops, since most users do not back up their data and when encrypting files, they lose all data. For organizations, this virus is less dangerous because they make backup copies of important data and, in case of infection, simply restore them, naturally after removing the virus. I encountered this virus several times, I will describe how it happened and what it led to.
The first time I encountered a virus that encrypts files was in early 2014. An administrator from another city contacted me and told me the most unpleasant news - All files on the file server are encrypted! The infection occurred in an elementary way - the accounting department received a letter with the attachment “Act of something there.pdf.exe”, as you understand, they opened this EXE file and the process began... it encrypted all personal files on the computer and went to the file server (it was connected by a network drive). The administrator and I started digging for information on the Internet... at that time there was no solution... everyone wrote that there was such a virus, it was not known how to treat it, the files could not be decrypted, perhaps sending the files to Kaspersky, Dr Web or Nod32 would help. You can only send them if you use their anti-virus programs (licensed). We sent the files to Dr Web and Nod32, the results were 0, I don’t remember what they said to Dr Web, and Nod 32 was completely silent and I didn’t get any response from them. In general, everything was sad and we never found a solution; we restored some of the files from backup.
The second story - just the other day (mid-October 2014) I received a call from an organization asking me to solve a problem with a virus; as you understand, all the files on the computer were encrypted. Here's an example of what it looked like.
As you can see, the extension *.AES256 was added to each file. In each folder there was a file “Attention_open-me.txt” which contained contacts for communication.
When trying to open these files, a program with contacts opened to contact the authors of the virus to pay for decryption. Of course, I do not recommend contacting them, or paying for the code either, since you will only support them financially and it is not a fact that you will receive the decryption key.
The infection occurred during the installation of a program downloaded from the Internet. The most surprising thing was that when they noticed that the files had changed (icons and file extensions had changed), they did nothing and continued to work, while the ransomware continued to encrypt all files.
Attention!!! If you notice encryption of files on your computer (change in icons, change in extension), immediately turn off your computer/laptop and look for a solution from another device (from another computer/laptop, phone, tablet) or contact IT specialists. The longer your computer/laptop is turned on, the more files it will encrypt.
In general, I already wanted to refuse to help them, but I decided to surf the Internet, maybe a solution to this problem had already appeared. As a result of searching, I read a lot of information that it cannot be decrypted, that you need to send files to antivirus companies (Kaspersky, Dr Web or Nod32) - thanks for the experience.
I came across a utility from Kaspersky - RectorDecryptor. And lo and behold, the files were decrypted. Well, first things first...
The first step is to stop the ransomware. You won’t find any antiviruses, because the installed Dr Web didn’t find anything. First of all, I went to startup and disabled all startups (except antivirus). Rebooted the computer. Then I started looking at what kind of files were in startup.
As you can see in the "Command" field it is indicated where the file is located, special attention needs to be removed for applications without a signature (Manufacturer - No data). In general, I found and deleted the malware and files that were not yet clear to me. After that, I cleared temporary folders and browser caches; it is best to use the program for these purposes CCleaner .
Then I started decrypting the files, for this I downloaded decryption program RectorDecryptor . I launched it and saw a rather ascetic interface of the utility.
I clicked “Start scanning” and indicated the extension that all changed files had.
And indicated the encrypted file. In newer versions of RectorDecryptor you can simply specify the encrypted file. Click the "Open" button.
Tada-a-a-am!!! A miracle happened and the file was decrypted.
After this, the utility automatically checks all computer files + files on the connected network drive and decrypts them. The decryption process may take several hours (depending on the number of encrypted files and the speed of your computer).
As a result, all encrypted files were successfully decrypted into the same directory where they were originally located.
All that remains is to delete all files with the extension .AES256; this could be done by checking the “Delete encrypted files after successful decryption” checkbox if you click “Change scan parameters” in the RectorDecryptor window.
But remember that it is better not to check this box, because if the files are not successfully decrypted, they will be deleted and in order to try to decrypt them again you will have to first restore .
When I tried to delete all encrypted files using standard search and delete, I encountered freezes and extremely slow operation of the computer.
Therefore, to remove it, it is best to use the command line, run it and write del"<диск>:\*.<расширение зашифрованного файла>"/f/s. In my case del "d:\*.AES256" /f /s.
Do not forget to delete the files "Attention_open-me.txt", to do this, use the command on the command line del"<диск>:\*.<имя файла>"/f/s, For example
del "d:\Attention_open-me.txt" /f /s
Thus, the virus was defeated and the files were restored. I want to warn you that this method will not help everyone, the whole point is that Kapersky in this utility has collected all the known decryption keys (from those files that were sent by those infected with the virus) and uses a brute force method to select the keys and decrypt them. Those. if your files are encrypted by a virus with an unknown key, then this method will not help... you will have to send the infected files to antivirus companies - Kaspersky, Dr Web or Nod32 to decrypt them.
Viruses themselves as a computer threat do not surprise anyone today. But if previously they affected the system as a whole, causing disruptions in its performance, today, with the advent of such a variety as an encryptor virus, the actions of a penetrating threat affect more user data. It poses perhaps an even greater threat than executable applications destructive to Windows or spyware applets.
What is a ransomware virus?
The code itself, written in a self-copying virus, involves encrypting almost all user data with special cryptographic algorithms, without affecting the system files of the operating system.
At first, the logic of the virus’s impact was not entirely clear to many. Everything became clear only when the hackers who created such applets began demanding money to restore the original file structure. At the same time, the encrypted virus itself does not allow you to decrypt files due to its characteristics. To do this, you need a special decryptor, if you like, a code, a password or an algorithm required to restore the desired content.
The principle of penetration into the system and operation of the virus code
As a rule, it is quite difficult to “pick up” such crap on the Internet. The main source of spread of the “infection” is email at the level of programs installed on a specific computer terminal, such as Outlook, Thunderbird, The Bat, etc. Let us note right away: this does not apply to Internet mail servers, since they have a fairly high degree of protection, and access access to user data is possible only at the level
Another thing is an application on a computer terminal. This is where the field for the action of viruses is so wide that it is impossible to imagine. True, it’s also worth making a reservation here: in most cases, viruses target large companies from which they can “rip off” money for providing a decryption code. This is understandable, because not only on local computer terminals, but also on the servers of such companies, files can be stored, so to speak, in a single copy, which cannot be destroyed under any circumstances. And then decrypting files after a ransomware virus becomes quite problematic.
Of course, an ordinary user can be subject to such an attack, but in most cases this is unlikely if you follow the simplest recommendations for opening attachments with extensions of an unknown type. Even if an email client detects an attachment with a .jpg extension as a standard graphic file, it must first be checked as standard installed on the system.
If this is not done, when you open it by double-clicking (standard method), the activation of the code will start and the encryption process will begin, after which the same Breaking_Bad (encryptor virus) will not only be impossible to remove, but also the files will not be able to be restored after the threat is eliminated.
General consequences of penetration of all viruses of this type
As already mentioned, most viruses of this type enter the system through email. Well, let’s say a large organization receives a letter to a specific registered email with contents like “We have changed the contract, scanned copy is attached” or “You have been sent an invoice for shipping the goods (a copy there).” Naturally, the unsuspecting employee opens the file and...
All user files at the level of office documents, multimedia, specialized AutoCAD projects or any other archival data are instantly encrypted, and if the computer terminal is located on a local network, the virus can be transmitted further, encrypting data on other machines (this becomes noticeable immediately after “braking” of the system and freezing of programs or currently running applications).
At the end of the encryption process, the virus itself apparently sends a kind of report, after which the company may receive a message that such and such a threat has penetrated the system, and that only such and such an organization can decrypt it. This usually involves a virus. [email protected]. Next comes a requirement to pay for decryption services with an offer to send several files to the client’s email, which is most often fictitious.
Harm from exposure to code
If anyone has not yet understood: decrypting files after a ransomware virus is a rather labor-intensive process. Even if you don’t give in to the demands of the attackers and try to involve official government agencies in combating and preventing computer crimes, usually nothing good comes of it.
If you delete all files, produce and even copy the original data from removable media (of course, if there is such a copy), everything will still be encrypted again if the virus is activated. So you shouldn’t delude yourself too much, especially since when you insert the same flash drive into a USB port, the user won’t even notice how the virus will encrypt the data on it too. Then you won't have any problems.
Firstborn in the family
Now let's turn our attention to the first encryption virus. At the time of its appearance, no one had yet thought how to cure and decrypt files after being exposed to an executable code contained in an email attachment with a dating offer. Awareness of the scale of the disaster came only with time.
That virus had the romantic name “I Love You”. An unsuspecting user opened an attachment in an email message and received completely unplayable multimedia files (graphics, video and audio). Back then, however, such actions looked more destructive (harm to user media libraries), and no one demanded money for it.
The newest modifications
As we see, the evolution of technology has become quite a profitable business, especially considering that many managers of large organizations immediately run to pay for decryption efforts, without thinking at all that they could lose both money and information.
By the way, don’t look at all these “wrong” posts on the Internet, saying, “I paid/paid the required amount, they sent me a code, everything was restored.” Nonsense! All this is written by the developers of the virus themselves in order to attract potential, excuse me, “suckers.” But, by the standards of an ordinary user, the amounts to pay are quite serious: from hundreds to several thousand or tens of thousands of euros or dollars.
Now let's look at the newest types of viruses of this type, which were recorded relatively recently. All of them are practically similar and belong not only to the category of encryptors, but also to the group of so-called ransomware. In some cases, they act more correctly (like paycrypt), seemingly sending official business offers or messages that someone cares about the security of the user or organization. Such an encrypting virus simply misleads the user with its message. If he takes even the slightest action to pay, that’s it - the “divorce” will be complete.
XTBL virus
This relatively recent one can be classified as a classic version of ransomware. Typically, it enters the system through email messages containing file attachments, which is standard for Windows screensavers. The system and user think everything is fine and activate viewing or saving the attachment.
Unfortunately, this leads to sad consequences: the file names are converted into a set of characters, and .xtbl is added to the main extension, after which a message is sent to the desired email address about the possibility of decryption after paying the specified amount (usually 5 thousand rubles).
CBF virus
This type of virus also belongs to the classics of the genre. It appears on the system after opening email attachments, and then renames user files, adding an extension like .nochance or .perfect at the end.
Unfortunately, decrypting a ransomware virus of this type to analyze the contents of the code even at the stage of its appearance in the system is not possible, since after completing its actions it self-destructs. Even what many believe is a universal tool like RectorDecryptor does not help. Again, the user receives a letter demanding payment, for which two days are given.
Breaking_Bad virus
This type of threat works in the same way, but renames files in the standard version, adding .breaking_bad to the extension.
The situation is not limited to this. Unlike previous viruses, this one can create another extension - .Heisenberg, so it is not always possible to find all infected files. So Breaking_Bad (a ransomware virus) is a fairly serious threat. By the way, there are cases where even the Kaspersky Endpoint Security 10 license package misses this type of threat.
Virus [email protected]
Here is another, perhaps the most serious threat, which is mostly aimed at large commercial organizations. As a rule, some department receives a letter containing seemingly changes to the supply agreement, or even just an invoice. The attachment may contain a regular .jpg file (such as an image), but more often - an executable script.js (Java applet).
How to decrypt this type of encryption virus? Judging by the fact that some unknown RSA-1024 algorithm is used there, no way. Based on the name, you can assume that this is a 1024-bit encryption system. But, if anyone remembers, today 256-bit AES is considered the most advanced.
Encryptor virus: how to disinfect and decrypt files using antivirus software
To date, no solutions have yet been found to decipher threats of this type. Even such masters in the field of antivirus protection as Kaspersky, Dr. Web and Eset cannot find the key to solving the problem when the system is infected with an encrypting virus. How to disinfect files? In most cases, it is suggested to send a request to the official website of the antivirus developer (by the way, only if the system has licensed software from this developer).
In this case, you need to attach several encrypted files, as well as their “healthy” originals, if any. In general, by and large, few people save copies of data, so the problem of their absence only aggravates an already unpleasant situation.
Possible ways to identify and eliminate the threat manually
Yes, scanning with conventional antivirus programs identifies threats and even removes them from the system. But what to do with the information?
Some try to use decryption programs like the already mentioned RectorDecryptor (RakhniDecryptor) utility. Let us note right away: this will not help. And in the case of the Breaking_Bad virus, it can only do harm. And that's why.
The fact is that people who create such viruses are trying to protect themselves and provide guidance to others. When using decryption utilities, the virus can react in such a way that the entire system crashes, with the complete destruction of all data stored on hard drives or logical partitions. This, so to speak, is an indicative lesson for the edification of all those who do not want to pay. We can only rely on official antivirus laboratories.
Cardinal methods
However, if things are really bad, you will have to sacrifice information. To completely get rid of the threat, you need to format the entire hard drive, including virtual partitions, and then install the operating system again.
Unfortunately, there is no other way out. Even up to a certain saved restore point will not help. The virus may disappear, but the files will remain encrypted.
Instead of an afterword
In conclusion, it is worth noting that the situation is this: a ransomware virus penetrates the system, does its dirty work and is not cured by any known methods. Anti-virus protection tools were not ready for this type of threat. It goes without saying that it is possible to detect a virus after exposure or remove it. But the encrypted information will remain unsightly. So I would like to hope that the best minds of antivirus software development companies will still find a solution, although, judging by the encryption algorithms, it will be very difficult to do. Just remember the Enigma encryption machine that the German Navy had during World War II. The best cryptographers could not solve the problem of an algorithm for decrypting messages until they got their hands on the device. This is how things are here too.
Has it ever happened that you received a message via Email, Skype or ICQ from an unknown sender with a link to a photo of your friend or congratulations on the upcoming holiday? You don’t seem to expect any kind of setup, and suddenly, when you click on the link, serious malicious software is downloaded to your computer. Before you know it, the virus has already encrypted all your files. What to do in such a situation? Is it possible to restore documents?
In order to understand how to deal with malware, you need to know what it is and how it penetrates the operating system. In addition, it does not matter at all what version of Windows you use - the Critroni virus is aimed at infecting any operating system.
Encryption computer virus: definition and algorithm of action
A new computer virus software has appeared on the Internet, known to many as CTB (Curve Tor Bitcoin) or Critroni. This is an improved Trojan ransomware, similar in principle to the previously known malicious software CriptoLocker. If a virus has encrypted all files, what should you do in this case? First of all, you need to understand the algorithm of its operation. The essence of the virus is to encrypt all your files with the extensions .ctbl, .ctb2, .vault, .xtbl or others. However, you will not be able to open them until you pay the requested amount of money.
Trojan-Ransom.Win32.Shade and Trojan-Ransom.Win32.Onion viruses are common. They are very similar to STV in their local action. They can be distinguished by the extension of the encrypted files. Trojan-Ransom encodes information in .xtbl format. When you open any file, a message appears on the screen stating that your personal documents, databases, photos and other files have been encrypted by malware. To decrypt them, you need to pay for a unique key, which is stored on a secret server, and only in this case will you be able to perform decryption and cryptographic operations with your documents. But don’t worry, much less send money to the specified number; there is another way to combat this type of cybercrime. If just such a virus got onto your computer and encrypted all the .xtbl files, what should you do in such a situation?
What not to do if an encryption virus penetrates your computer
It happens that in a panic we install an antivirus program and, with its help, automatically or manually remove virus software, losing important documents along with it. This is unpleasant, in addition, the computer may contain data that you have been working on for months. It's a shame to lose such documents without the possibility of their recovery.
If the virus has encrypted all .xtbl files, some try to change their extension, but this also does not lead to positive results. Reinstalling and formatting the hard drive will permanently remove the malicious program, but at the same time you will lose any possibility of document recovery. In this situation, specially created decryption programs will not help, because the ransomware software is programmed using a non-standard algorithm and requires a special approach.
How dangerous is a ransomware virus for a personal computer?
It is absolutely clear that not a single malicious program will benefit your personal computer. Why is such software created? Oddly enough, such programs were created not only for the purpose of defrauding users of as much money as possible. In fact, viral marketing is quite profitable for many antivirus inventors. After all, if a virus encrypted all the files on your computer, where would you turn first? Naturally, seek the help of professionals. What is encryption for your laptop or personal computer?
Their operating algorithm is non-standard, so it will be impossible to cure infected files with conventional anti-virus software. Removing malicious objects will result in data loss. Only moving to quarantine will make it possible to secure other files that the malicious virus has not yet managed to encrypt.
Expiration date of encryption malware
If your computer is infected with Critroni (malware) and the virus has encrypted all your files, what should you do? You cannot decrypt .vault-, .xtbl-, .rar formats yourself by manually changing the extension to .doc, .mp3, .txt and others. If you do not pay the required amount to cybercriminals within 96 hours, they will send you intimidating correspondence by email stating that all your files will be permanently deleted. In most cases, people are influenced by such threats and they reluctantly but obediently carry out the said actions, fearing to lose precious information. It's a pity that users do not understand the fact that cybercriminals are not always true to their word. Once they receive the money, they often no longer worry about decrypting your locked files.
When the timer expires, it closes automatically. But you still have a chance to recover important documents. A message will appear on the screen indicating that time has expired, and you can view more detailed information about the files in the documents folder in a specially created notepad file DecryptAllFiles.txt.
Ways encryption malware penetrates the operating system
Typically, ransomware viruses enter a computer through infected email messages or through fake downloads. These could be fake flash updates or fraudulent video players. As soon as the program is downloaded to your computer using any of these methods, it immediately encrypts the data without the possibility of recovery. If the virus has encrypted all .cbf, .ctbl, .ctb2 files into other formats and you do not have a backup copy of the document stored on removable media, assume that you will no longer be able to recover them. At the moment, antivirus laboratories do not know how to crack such encryption viruses. Without the required key, you can only block infected files, move them to quarantine or delete them.
How to avoid getting a virus on your computer
Ominous all .xtbl files. What to do? You have already read a lot of unnecessary information that is written on most websites, and you cannot find the answer. It so happens that at the most inopportune moment, when you urgently need to submit a report at work, a thesis at a university, or defend your professor’s degree, the computer begins to live its own life: it breaks down, becomes infected with viruses, and freezes. You must be prepared for such situations and keep information on the server and removable media. This will allow you to reinstall the operating system at any time and after 20 minutes work at the computer as if nothing had happened. But, unfortunately, we are not always so enterprising.
To avoid infecting your computer with a virus, you first need to install a good antivirus program. You must have a properly configured Windows Firewall, which protects against various malicious objects getting through the Network. And the most important thing: do not download software from unverified sites or torrent trackers. To avoid infecting your computer with viruses, be careful what links you click on. If you receive an email from an unknown recipient with a request or offer to see what is hidden behind the link, it is best to move the message to spam or delete it altogether.
To prevent the virus from encrypting all .xtbl files one day, antivirus software laboratories recommend a free way to protect against infection by encryption viruses: once a week, inspect their status.
The virus has encrypted all files on the computer: treatment methods
If you have become a victim of cybercrime and the data on your computer has been infected by one of the encrypting types of malware, then it is time to try to recover your files.
There are several ways to treat infected documents for free:
- The most common method, and probably the most effective at the moment, is backing up documents and then restoring them in the event of an unexpected infection.
- The software algorithm of the CTB virus works in an interesting way. Once on the computer, it copies files, encrypts them, and deletes the original documents, thereby eliminating the possibility of their recovery. But with the help of Photorec or R-Studio software, you can manage to save some untouched original files. You should know that the longer you use your computer after it has been infected, the less likely it is that you will be able to recover all the necessary documents.
- If the virus has encrypted all .vault files, there is another good way to decrypt them - using shadow copy volumes. Of course, the virus will try to permanently and irrevocably delete them all, but it also happens that some files remain untouched. In this case, you will have a small but chance of restoring them.
- It is possible to store data on file hosting services such as DropBox. It can be installed on your computer as a local disk mapping. Naturally, the encryption virus will infect him too. But in this case, it is much more realistic to restore documents and important files.
Software prevention of personal computer virus infection
If you are afraid of sinister malicious software getting onto your computer and do not want an insidious virus to encrypt all your files, you should use the local policy editor or Windows group editor. Thanks to this integrated software, you can set up a program restriction policy - and then you will not be worried about your computer becoming infected.
How to recover infected files
If the CTB virus has encrypted all files, what should you do in this case to restore the necessary documents? Unfortunately, at the present time, not a single anti-virus laboratory can offer decryption of your files, but neutralizing the infection and completely removing it from a personal computer is possible. All effective methods of information recovery are listed above. If your files are too valuable to you, and you did not bother to back them up to a removable drive or Internet drive, then you will have to pay the amount of money requested by the cybercriminals. But there is no chance that the decryption key will be sent to you even after payment.
How to find infected files
To see the list of infected files, you can go to this path: “My Documents”\.html or “C:”\”Users”\”All Users”\.html. This html sheet contains data not only about random instructions, but also about infected objects.
How to block an encryption virus
Once a computer has been infected with malware, the first necessary action on the part of the user is to turn on the network. This is done by pressing the F10 keyboard key.
If the Critroni virus accidentally got onto your computer and encrypted all files in .rar, .ctbl, .ctb2, .xtbl, .vault, .cbf or any other format, then it is already difficult to recover them. But if the virus has not yet made many changes, it is likely to be blocked using a software restriction policy.