This video shows the behavior of a type of ransomware called CryptoLocker. For more information on how Sophos protects you: http://blogs.sophos.com/2013/10/1. When a virus like Trojan, Melissa, I Love You, Code Red, Zeus or any other types of virus like Wannacry Ransomware enters into your system,it encrypts your files and make it inaccessible due to which it is very hard for a user to use those files. In recent times, Wannacry Ransomware attack is the most recent one and trust me it created havoc. I have a computer infected with CryptoLocker Virus which has encrypted all the files. The user had the backup drive attached when the virus was activated so the backups are encrypted too. I have uploaded a filename.doc.encrypted file to the www.decryptcryptlocker.com site but it returns Invalid file The file does not seem to be infected.

• Cryptolocker is a malware threat that gained notoriety over the last years. It is a Trojan horse that infects your computer and then searches for files to encrypt. This includes anything on your hard drives and all connected media — for example, USB memory sticks or any shared network drives.
• I know these are a lot. And, I hope you got the idea of the range of CryptoLocker virus now The files encrypted by Cerber ransomware are almost similar to CryptoLocker virus. CryptoLocker Removal Tool & Guide. Considering the risk level of the CryptoLocker ransomware, I don’t think there is a single tool that can get rid of it from the root.
• The aim of test viruses is to test the functions of an anti-malware program or to see how the program behaves when a virus is detected. Download the desired test file to your PC. If your network security does not already prevent the download of the file, the local antivirus program should start working when trying to save or execute the file.
• What is ransomware? It’s a malware (a Trojan or another type of virus) that locks your device or encrypts your files, and then tells you that you have to pay ransom to get your data back. It’s not cheap, and there’s no guarantee of success. If you become a victim of ransomware, try our free decryption tools and get your digital life back.

Ransomware CryptoLocker was one of the most infamous malware families of the years 2013 and 2014 and although the operation behind the original CryptoLocker malware family has been dismantled in 2014, it’s still a name that frightens a lot of users and system administrators alike. It is therefore not surprising that other malware authors try to capitalize on CryptoLocker’s reputation by releasing copycats. One of the most recent copycats that we became aware of is a ransomware named PClock that showed up just a day ago. Unlike CryptoLocker though, which was a somewhat complex and sophisticated piece of malware, PClock is quite primitive by nature.

72-hour countdown timer to pay USD$300 ransom

Like all file encrypting ransomware (also known as crypto malware) PClock’s main goal is to encrypt important files on the victim’s system in order to compel them to pay a ransom in return for their files. Like CryptoLocker it gives the user a 72-hour ultimatum to pay the ransom of 1 bitcoin (approximately USD $300). Otherwise it claims to destroy the keys required to decrypt the user’s files:

If a user does not pay the ransom within the allotted time, it will display a last_chance.txt file that tells the user to download the malware again, which supposedly gives you another 3 days to make the payment. In reality though PClock does not destroy any keys, so the countdown is pretty much meaningless.

How PClock infects a new system

At this point it is not entirely clear how PClock, which is written in Visual Basic 6, enters a user’s system. Once it manages to to execute on the victim’s system however, it will copy itself to the current user’s application data folder using the sub-folder “WinCL” and the file name “WinCL.exe”. It then establishes persistence by creating a new registry value within the HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun key named “wincl” pointing towards the newly created WinCL.exe executable. The malware then tries to encrypt the victims’s files. It specifically targets files with one of the following extensions:

*.3fr, *.accdb, *.ai, *.arw, *.bay, *.cdr, *.cer, *.cr2, *.crt, *.crw, *.h, *.dbf, *.dcr, *.der, *.dng, *.doc, *.docm, *.docx, *.dwg, *.dxf, *.dxg, *.eps, *.erf, *.indd, *.jpe, *.jpg, *.kdc, *.mdb, *.mdf, *.mef, *.mrw, *.nef, *.nrw, *.odb, *.odm, *.odp, *.ods, *.odt, *.orf, *.p12, *.p7b, *.p7c, *.pdd, *.pef, *.pem, *.pfx, *.ppt, *.pptm, *.pptx, *.psd, *.pst, *.ptx, *.r3d, *.raf, *.raw, *.rtf, *.rw2, *.rwl, *.srf, *.srw, *.wb2, *.wpd, *.wps, *.xlk, *.xls, *.xlsb, *.xlsm, *.xlsx

Every files the malware tries to encrypt is recorded within a file named “enc_files.txt” located in the victim’s profile folder. After the encryption has finished the malware will try to delete and disable all shadow copies. Shadow copies is the technology that powers the Windows’ “Previous Version” feature that allows a user to restore previous versions of a file. This feature is often used by ransomware victims to recover their files so a lot of ransomware families started to destroy any previous versions created by the shadow copy service. Last but not least the malware will create a shortcut to itself on the victims’s desktop and change the victims’s desktop wallpapter to the following picture:

During the infection and encryption process the malware will try to maintain a log on the malware author’s command and control server:

P04552 8:08:02 AM Files encrypted
P04552 8:08:02 AM STATE: CRYPTED_OK
P04552 8:08:02 AM Delete shadows
P04552 8:08:04 AM Shadows: no ADMIN
P04552 8:11:06 AM Shadows deleted
P04552 8:11:06 AM STATE: SHADOWS_OK
P04552 8:11:06 AM Prepare
P04552 8:11:08 AM Saved BTC price – 330
P04552 8:11:11 AM Shortcut created
P04552 8:11:12 AM STATE: PREPARE_OK
P04552 8:11:12 AM Change wallpaper
P04552 8:11:13 AM Wallpaper changed

This excerpt shows an example of an infection taking place to give you an idea about what is being logged.

PClock: a lot of show but little substance

Similar to the countdown, the ransom note is far from the truth as well and even though the malware may look somewhat professional at first glance it becomes obvious quickly that the people behind it are amateurs at best. The encryption algorithm used for example is just a simple XOR based obfuscation that uses a constant key on all systems. Due to that we are able to provide a decrypter that can be found further down this post. A more severe sign for the lack of professionalism is the fact that the malware contains several disastrous bugs that may cause data loss on the victim’s system. If the malware encounters a particularly large file for example that is too big to fit into memory the malware will end up truncating the existing file instead of encrypting it. The result is a 0-byte file that contains neither the original nor the encrypted file content. Once the malware messed up a file like that the last hope for the victim are data recovery tools.

How to unlock your encrypted files

As mentioned before the encryption used by PClock is extremely weak and can easily be reverted. To help and guide you in that process we developed a small decrypter utility. Our decrypter will enable you to decrypt any PClock encrypted files that haven’t been damaged beyond repair by the malware and clean up your computer without having to pay the ransom. You can download our decrypter here: http://emsi.at/DecryptPClock

The decrypter will use a list of encrypted files the malware stores on the victim’s system to determine which files are in need of decryption. This list is loaded automatically when you start the decrypter and in theory all you would have to do is load up the decrypter and hit the “Decrypt” button. In practice it isn’t that simple though due to the fact that the malware does not provide enough information for the decrypter to be absolutely sure that the decrypted file is exactly like the original unencrypted one that the malware targetted. We therefore decided to play it safe and keep backups of all encrypted files. These backups will take a lot of disk space and essentially double the amount of space required on your hard disk to hold both the decrypted file as well as the encrypted backup. If you are running low on disk space you can disable the backups in the decrypter’s option menu. This should be a last resort though and before you try to use the decrypter that way you should try the decrypter out on a small number of test files that you can verify manually to make sure the decrypter is operating correctly.

If you don’t feel comfortable performing the decryption process on your own, feel free to create a support request in our support forum or send us an email.

UPDATE 2015-01-06, 8PM UTC: An updated version of PClock was released where this decrypter does not work with yet. We’re working on an update. Please return in a couple of hours if you are affected by the threat. Please also read this thread at the Bleepingcomputer forum where this topic is discussed.

Download Cryptolocker Virus For Testing Tool

UPDATE 2015-01-09: the malware authors released two more versions of PClock. The good news is that the Emsisoft decrypter is ready and works for both versions. You can download the Emsisoft decrypter version 2 here. Read the instructions thoroughly first on page 8 in the Bleepingcomputer forum discussion.

UPDATE 2015-01-10: new decrypter developed, download here: http://emsi.at/DecryptPClock2. Please read the Bleepingcomputer discussion thoroughly for instructions.

NOTE: Emsisoft’s Fabian developed this decrypter in his spare time for victims of PClock. If you’re a victim, please read the instructions entirely before starting the process. To prevent getting infected in the first place, use Emsisoft Anti-Malware for complete protection against ransomware, viruses and all other sorts of malware. We’d appreciate it if you share this post so that more victims of PClock can be helped.

Have a great (ransom-free) day!

Download Cryptolocker Virus For Testing Near Me

CryptoLocker is by now a well known piece of malware that can be especially damaging for any data-driven organization. Once the code has been executed, it encrypts files on desktops and network shares and “holds them for ransom”, prompting any user that tries to open the file to pay a fee to decrypt them. For this reason, CryptoLocker and its variants have come to be known as “ransomware.”

Malware like CryptoLocker can enter a protected network through many vectors, including email, file sharing sites, and downloads. New variants have successfully eluded anti-virus and firewall technologies, and it’s reasonable to expect that more will continue to emerge that are able to bypass preventative measures. In addition to limiting the scope of what an infected host can corrupt through buttressing access controls, detective and corrective controls are recommended as a next line of defense.

Want to learn ransomware basics and earn a CPE credit? Try our free course.

FYI, this article is CryptoLocker specific. If you’re interested in reading about ransomware in general, we’ve written A Complete Guide To Ransomware that is very in-depth.

Download Cryptolocker Virus For Testing Software

CryptoLocker Behavior

On execution, CryptoLocker begins to scan mapped network drives that the host is connected to for folders and documents (see affected file-types), and renames and encrypts those that it has permission to modify, as determined by the credentials of the user who executes the code. CryptoLocker uses an RSA 2048-bit key to encrypt the files, and renames the files by appending an extension, such as, .encrypted or .cryptolocker or .[7 random characters], depending on the variant. Finally, the malware creates a file in each affected directory linking to a web page with decryption instructions that require the user to make a payment (e.g. via bitcoin). Instruction file names are typically DECRYPT_INSTRUCTION.txt or DECRYPT_INSTRUCTIONS.html.

As new variants are uncovered, information will be added to the Varonis Connect discussion on Ransomware. For example, a variant known as “CTB-Locker” creates a single file in the directory where it first begins to encrypt files, named, !Decrypt-All-Files-[RANDOM 7 chars].TXT or !Decrypt-All-Files-[RANDOM 7 chars].BMP.

Mitigation Tips

Prevent What’s Preventable

The more files a user account has access to, the more damage malware can inflict. Restricting access is therefore a prudent course of action, as it will limit the scope of what can be encrypted. In addition to offering a line of defense for malware, it will mitigate potential exposure to other attacks from both internal and external actors.

While getting to a least privilege model is not a quick fix, it’s possible to reduce exposure quickly by removing unnecessary global access groups from access control lists. Groups like “Everyone,” “Authenticated Users,” and “Domain Users,” when used on data containers (like folders and SharePoint sites) can expose entire hierarchies to all users in a company. In addition to being easy targets for theft or misuse, these exposed data sets are very likely to be damaged in a malware attack. On file servers, these folders are known as “open shares,” if both file system and sharing permissions are accessible via a global access group.

Although it’s easiest to use technologies designed to find and eliminate global access groups, it is possible to spot open shares by creating a user with no group memberships, and using that account’s credentials to “scan” the file sharing environment. For example, even basic net commands from a windows cmd shell can be used to enumerate and test shares for accessibility:

• net view (enumerates nearby hosts)
• net view host (enumerates shares)
• net use X: hostshare (maps a drive to the share)
• dir /s (enumerates all the files readable by the user under the share)

These commands can be easily combined in a batch script to identify widely accessible folders and files. Remediating these without automation, unfortunately, can be a time-consuming and risky endeavor, as it’s easy to affect normal business activity if you’re not careful. If you uncover a large amount of accessible folders, consider an automated solution. Automated solutions can also help you go farther than eliminating global access, making it possible to achieve a true least-privilege model and eliminate manual, ineffective access-control management at the same time.

Detect What You Can Detect

If file access activity is being monitored on affected files servers, these behaviors generate very large numbers of open, modify, and create events at a very rapid pace, and are fairly easy to spot with automation, providing a valuable detective control. For example, if a single user account modifies 100 files within a minute, it’s a good bet something automated is going on. Configure your monitoring solution to trigger an alert when this behavior is observed. Instructions for configuring an automated alert with Varonis are available here (login required).

If you don’t have an automated solution to monitor file access activity, you may be forced to enable native auditing. Native auditing, unfortunately, taxes monitored systems and the output is difficult to decipher. Instead of attempting to enable and collect native audit logs on each system, prioritize particularly sensitive areas and consider setting up a file share honeypot.

Download Cryptolocker Virus For Testing Sites

A file share honeypot is an accessible file share that contains files that look normal or valuable, but in reality are fake. As no legitimate user activity should be associated with a honeypot file share, any activity observed should be scrutinized carefully. If you’re stuck with manual methods, you’ll need to enable native auditing to record access activity, and create a script to alert you when events are written to the security event log (e.g. using dumpel.exe).

If you’re PowerShell inclined, we’ve written a bit on how to combat CryptoLocker with PowerShell.

Correct What You Detect Faster with Automation

If your detective control mechanism can trigger an automated response, such as disabling the user account, the attack is effectively stopped before inflicting further damage. For example, a response to a user that generates more than 100 modify events within a minute might include:

• Notifying IT and security administrators (include the affected username and machine)
• Checking the machine’s registry for known keys/values that CryptoLocker creates:
  • Get-Item HKCU:SoftwareCryptoLockerFiles).GetValueNames()
• if value exists, disable user automatically.

Recover with Confidence

M audio oxygen 49 studio one. If recorded access activity is preserved and adequately searchable, it becomes invaluable in recovery efforts, as it provides a complete record of all affected files, user accounts, and (potentially) hosts. Varonis customers can use the output from report 1a (as described here) to restore files from a backup or shadow copy.

Depending on the variant of CryptoLocker, encryption may be reversible with a real-time disassembler.

Need Help?

Contact us if you have questions, or if you’d like to set up a free consultation.

Want more helpful tips like this including in-depth articles and scripts that we don’t post publicly? Visit the Security Corner in our Varonis Connect community.

*.zip ; *.rar ; *.7z ; *.tar ; *.gzip ; *.jpg ; *.jpeg ; *.tif ; *.psd ; *.cdr ; *.dwg ; *.max ; *.bmp ; *.gif ; *.png ; *.doc ; *.docx ; *.xls ; *.xlsx ; *.ppt ; *.pptx ; *.txt ; *.pdf ; *.djvu ; *.htm ; *.html ; *.mdb ; *.cer ; *.p12 ; *.pfx ; *.kwm ; *.pwm ; *.1cd ; *.md ; *.mdf ; *.dbf ; *.odt ; *.vob ; *.iso ; *.ifo ; *.csv ; *.torrent ; *.mov ; *.m2v ; *.3gp ; *.mpeg ; *.mpg ; *.flv ; *.avi ; *.mp4 ; *.wmv ; *.divx ; *.mkv ; *.mp3 ; *.wav ; *.flac ; *.ape ; *.wma ; *.ac3 ; *.epub ; *.eps ; *.ai ; *.pps ; *.pptm ; *.accdb ; *.pst ; *.dwg ; *.dxf ; *.dxg ; *.wpd ; *.dcr ; *.kdc ; *.p7b ; *.p7c ; *.raw ; *.cdr ; *.qbb ; *.indd ; *.qbw