Redmat ransomware is new variant of STOP file-encrypting virus that was made to generate profit through ransom payment from its victims. This clan of ransom virus is considered as one of the most spread malware using various channels of deployment. Though, its main distribution scheme is via spam email campaign where Redmat virus is attached, disguising as usual file like document, spreadsheet, presentation file, and so on.
Due to misleading email content, the attackers are always successful in persuading users to open the file. The execution gives Redmat to reside on the computer and in succession; it will drop several executable files and registry entries, which gives the malicious code a chance to run on each Windows startup.
After completing system infection, Redmat proceeds to main attack stage in which it will look for target files and apply a sophisticated encryption algorithm to lock it. One sign that file is encrypted is an appended .redmat extension. To site an example, document.doc will become document.doc.redmat after the encryption.
Included on each directory of infected files is a ransom note stating that users may only restore the encrypted file by paying for unique key and decryption tool. Similar to most ransomware, Redmat also demands the payment to be in Bitcoin currency. Cyber crooks necessitate for this type of payment method because it does not require personal details during transaction. Therefore, it leaves no trace and attackers can easily move around the ransom payment without getting caught.
Here is an excerpt from ransom note of Redmat:
Don’t worry my friend, you can return all your files!
All your files like photos, 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.
How to Remove Redmat Ransomware
Ransomware files are placed deeply into the system and on various locations, thus, thorough scanning is vital to totally remove Redmat virus. Aside from our suggested tool, you may also run your own security program.
Though affected files may be impossible to decrypt due to complexity of the encryption, you can still try recovery method like Shadow Explorer or Previous Version as described below.
Stage 1: Scan the Computer with ESET Rogue Application Remover (ERAR)
1. Download the free scanner called ESET Rogue Application Remover.
Download Link for ERAR (this will open a new window)
2. Choose appropriate version for your Windows System. Save the file to a convenient location, preferably on Desktop.
3. After downloading the file, Windows will prompt that download has completed. Click Run to start the program. Another option is to browse the location folder and double click on the file ERARemover_.exe.
4. On ESET Rogue Application Remover SOFTWARE LICENSE TERMS, click Accept to continue.
5. The tool will start scanning the computer. It will prompt when it finds Redmat virus and other malicious entities. Follow the prompt to proceed with the removal.
Stage 2: Double-check for Redmat’s leftover with Microsoft’s Malicious Software Removal Tool
1. Download the free scanner called Malicious Software Removal Tool.
Malicious Software Removal Tool Download Link (this will open a new window)
2. The tool automatically checks the operating system and suggest appropriate download version. Click on Download button to begin. Save the file to a convenient location, preferably on Desktop.
3. After downloading the file, Windows will prompt that download has completed. Click Run to start scanning for Redmat. Another option is to browse the location folder and double click on the file to run.
4. The tool will display Welcome screen, click Next. Please note the message “This tool is not a replacement for an antivirus product.” You must understand that this program is made specifically to find and remove malware, viruses, Trojans, and other harmful elements on the computer. It was not designed to protect the computer.
5. Next, you will see Scan Type. Please choose Full Scan to ensure that all Redmat virus entities and other harmful files left on the computer will be found and removed. For advanced computer user, you can opt for Customized Scan, if there are other drives or folders you wanted to include in this scan.
6. Full scan may take a while, please wait for Malicious Software Removal Tool to complete the tasks. However, you may cancel the scan anytime by clicking on the Cancel button.
7. After scanning, the tool will reveal all identified threats. There may be other threats that our first scan fails to detect. Please remove/delete all detected items.
8. When removal procedure is complete, you may now close Malicious Software Removal Tool. We hope that Redmat have been completely deleted from the computer. Please restart Windows to proceed with the normal operation.
Stage 3 : Unlocking files with Redmat Decryption Tool
So far, this Redmat decryption tool works only for files that were encrypted using offline keys. This happens sometimes if the virus is unable to communicate to remote server to obtain unique keys; instead, it will use offline keys when encrypting files. However, there is a little chance of recovering files using this tool due to limited available offline keys that were integrated with this decryption tool.
For additional information (download link, supported versions, instructions) about StopDecrypter, please proceed to ransomware decryption tool archive page.
If you received a message stating that “No keys were found for the following IDs (.redmat)”, please copy and submit the information to the official download page to include your information (log file) and have it archive in case decryption software becomes available.
We will update this section once the full decryption tool is on hand. In the meantime, please try other options below.
Option 1: Windows Previous Version Tool
Windows Vista and Windows 7 have a feature called Previous Versions. However, this tool is only usable if restore point was made prior to Redmat virus infection. To use this tool and recover files affected by the virus, please follow these steps:
1. Open My Computer or Windows Explorer.
2. Right-click on the affected files or folders. From the drop-down list, please click on Restore previous versions.
3. New window will open display all backup copy of files and folders you wanted to recover. Choose the appropriate file and click on Open, Copy, or Restore. Restoring selected files overwrites the current encrypted files on the computer.
Option 2: Use ShadowExplorer to restore files encrypted by Redmat
Just like Previous Version tool, ShadowExplorer is taking advantage of shadow copy created by Windows. This tool allows you to retrieve older version of files before it was encrypted by Redmat.
1. Download ShadowExplorer from the official web site.
2. Install the program with the default settings.
3. The program should run automatically after installation. If not, double-click on ShadowExplorer icon.
4. You can see the drop-down list on top of the console. Please select proper drive and the most recent point-in-time shadow copies of files you wish to restore prior to Redmat infection.
5. Right-click on the Drive, Folder, or File you wish to restore and click Export…
6. Lastly, ShadowExplorer will prompt for location where you want to save the copy of recovered files.