CRAT virus removal guide
What is CRAT?
CRAT is the name of a Remote Access Trojan (RAT). RAT is a form of malware that allows cyber criminals to control infected devices remotely. Research shows that this RAT (depending on its version) can be used not only to access and control computers, but also to download and install additional malicious components allowing to capture victim's screen, log keystrokes, monitor clipboard and encrypt files with ransomware.
CRAT can be used to collect system information such as installed antivirus software (and firewall), sizes of files folders, list of connected drives, collect data such as free and total disk space. Also, it can be used to read files (their contents) and write temporary files by using data that is received from a Command and Control (C2) server, execute commands, open a reverse command shell so that infected computer could be used to communicate back to the device controlled by cyber criminals, steal credentials (usernames and passwords) from Google Chrome browser. It can be used to manage files (move them to different locations), delete files and folders, create archive files (RAR) too. If necessary, cyber criminals can uninstall CRAT from the infected system as well. The newer (second) CRAT version can be used to download and install additional plugins that would expand RAT's capabilities. Those features would allow cyber criminals to use CRAT to record victim's screen (or take screenshots), log keystrokes, see what data is saved on the system clipboard and encrypt files with ransomware. By being able to record keystrokes cyber criminals could record data that victims enter with a keyboard. Usually cyber criminals target information such as credit card details, login credentials (usernames, passwords). CRAT's ransomware plugin is named Hansom. It puts files in password-protected RAR archive files (their passwords are encrypted using RSA public key) and creates the "HANSOM_README.tx" file (ransom note). Its ransom note contains instructions on how to pay a ransom, contact cyber criminals and some other details. Also, HANSOM changes victim's desktop wallpaper and deletes disk shadow copies.
|Name||CRAT remote access trojan|
|Threat Type||Trojan, password-stealing virus, banking malware, spyware.|
|Detection Names||Avast (Win64:Trojan-gen), BitDefender (Trojan.GenericKDZ.69148), ESET-NOD32 (A Variant Of Win64/NukeSped.EI), Kaspersky (Trojan.Win64.Agent.qwhvrb), Full List (VirusTotal)|
|Symptoms||Trojans are designed to stealthily infiltrate the victim's computer and remain silent, and thus no particular symptoms are clearly visible on an infected machine.|
|Distribution methods||Infected email attachments, malicious online advertisements, social engineering, software 'cracks'.|
|Damage||Stolen passwords, and banking information, identity theft, monetary and data loss|
|Malware Removal (Windows)||
To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Malwarebytes.
To sum up, cyber criminals behind CRAT can cause victims a number of serious problems, for example, monetary, data loss, identity theft, loss of access to a variety of accounts, other serious issues related to online privacy, browsing safety, etc. A couple of examples of other RATs are PyXie, Quaverse and GravityRAT.
How did CRAT infiltrate my computer?
How to avoid installation of malware?
Programs (and files) should be downloaded only from trustworthy, official web pages and via direct download links. They should not be downloaded via third party downloaders, Peer-to-Peer networks (e.g., torrent clients, eMule) and other sources, tools of this kind. Programs should not be installed via third party installers either. Irrelevant emails that are sent from unknown, suspicious addresses and have some files attached to them (or contain website links) should not be trusted. More often than not such emails are used by cyber criminals as tools to trick recipients into installing malware. Installed software has to be activated and/or updated with tools or functions that are designed by its official developers. Third party, unofficial tools should never be used neither to update or activate software. Moreover, it is illegal to activate licensed software with unofficial ('cracking') tools or use installers for pirated software. Additionally, a computer should be scanned for threats regularly, it is advised to use an up-do-date and reputable antivirus or anti-spyware software for that. If you believe that your computer is already infected, we recommend running a scan with Malwarebytes for Windows to automatically eliminate infiltrated malware.
The ransom note ("HANSOM_README.txt") generated by Hansom ransomware:
Text in this note:
What happened to My Computer?
Your important files are encrypted.
any of your documents, photos, videos, databases and other files are no longer accessible because they have been encrypted.
Maybe you are busy looking for a way to recover your files, but do not waste your time.
Nobody can recover your files without my decryption service.
Do not attempt to decrypt the data yourself, you might corrupt your files.
Don't Delete Encrypted Files.
Don't Modify Encrypted Files.
Don't Rename Encrypted Files.
Can I Recover My Files?
Sure. I guarantee that you can recover all your files safely and easily.
If you want to decrypt all of your files, you need to pay.
Hurry up! You only have 1 day(24 hours) of payment. After the deadline the price will be doubled.
If you do NOT pay in 3 days, you lose the chance to recover your files FOREVER.
How Do I Pay?
Payment is accepted in Bitcoin only.
The price of your valuable data will be determined as a result of the negotiation between you and me.
After negotiation, please buy that amount of bitcoin, and send it to my address below.
Please buy that amount of bitcoin, and send it to my address below.
For more informations, please google "How to buy bitcoin".
My bitcoin wallet address is
WARNING: Please check my bitcoin address carefully, even if you type one incorrect character, I can not receive your payment. After you send the bitcoin to my caress, you must send email with your bitcoin wallet address and your ransom id.
Your ransom ID is
And my email addresses are below.
WARNING: If all of my email addresses are blocked by cyber security teams, you will never be able to contact with me forever.
Screenshot of the Hansoms' desktop wallpaper:
Text in this wallpaper:
>> Oh, No! <<
All of your valuable data have been encrypted by HANSOM ransomware.
Please read HANSOM_README.txt on your desktop carefully. NEVER delete or modify Hansom Decrypt.exe on your desktop until you recover all of your data.
Instant automatic malware removal:
Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Malwarebytes is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
How to remove malware manually?
Manual malware removal is a complicated task - usually it is best to allow antivirus or anti-malware programs to do this automatically. To remove this malware we recommend using Malwarebytes for Windows. If you wish to remove malware manually, the first step is to identify the name of the malware that you are trying to remove. Here is an example of a suspicious program running on a user's computer:
If you checked the list of programs running on your computer, for example, using task manager, and identified a program that looks suspicious, you should continue with these steps:
Download a program called Autoruns. This program shows auto-start applications, Registry, and file system locations:
Restart your computer into Safe Mode:
Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.
Video showing how to start Windows 7 in "Safe Mode with Networking":
Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.
Video showing how to start Windows 8 in "Safe Mode with Networking":
Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.
Video showing how to start Windows 10 in "Safe Mode with Networking":
Extract the downloaded archive and run the Autoruns.exe file.
In the Autoruns application, click "Options" at the top and uncheck "Hide Empty Locations" and "Hide Windows Entries" options. After this procedure, click the "Refresh" icon.
Check the list provided by the Autoruns application and locate the malware file that you want to eliminate.
You should write down its full path and name. Note that some malware hides process names under legitimate Windows process names. At this stage, it is very important to avoid removing system files. After you locate the suspicious program you wish to remove, right click your mouse over its name and choose "Delete".
After removing the malware through the Autoruns application (this ensures that the malware will not run automatically on the next system startup), you should search for the malware name on your computer. Be sure to enable hidden files and folders before proceeding. If you find the filename of the malware, be sure to remove it.
Reboot your computer in normal mode. Following these steps should remove any malware from your computer. Note that manual threat removal requires advanced computer skills. If you do not have these skills, leave malware removal to antivirus and anti-malware programs. These steps might not work with advanced malware infections. As always it is best to prevent infection than try to remove malware later. To keep your computer safe, install the latest operating system updates and use antivirus software.
To be sure your computer is free of malware infections, we recommend scanning it with Malwarebytes for Windows.