This is a security brief for the newly discovered ransomware called Retis. This brief will contain technical information related to how it infects a computer, how it is distributed, and whether it can be decrypted or not.
The Retis Ransomware was discovered by security researcher SDK on December 19th 2017. This is a .NET ransomware, so its source code is easily accessible. When started it will first target the victim’s Desktop, Documents, and Pictures folder for encryption. After encrypting those folder, it will target the rest of the drives on the computer.
When encrypting a file it will use AES encryption and use a static key of “m4aP}2a_Jd`H~=k9aML58-ZJwy/j:e5Q” and IV of “R<0]W&JCfaD^(‘FX”. After encrypting a file it will append the .crypted extension to the filename.
The file extensions targeted by this ransomware are:
.txt, .doc, .docx, .xls, .xlsx, .ppt, .pptx, .jpg, .jpeg, .png, .one, .pdf
Finally, it will change the Windows wallpaper as %APPDATA%RANSOM.png, which is from an embedded resource in the executable. The executable also contains a secpmd image resource of a mountain range, but it is not used.
Method of Distribution
It is not currently known if this ransomware is distributed or how it is distributed.
Origin of Name
The name is taken from the string of text found in both the console while Retis is running and ransom note wallpaper that it will set. In both of these locations the string “Hack Lab by Retis” is displayed.
Is Retis Decryptable?
Yes, in its current state, the Retis Ransomware can be decrypted because it uses a static key that can be retrieved by the executable. If anyone becomes a victim of this ransomware, please contact us and we will see if we can create a decryptor for you.
How to protect yourself from Retis Ransomware
In order to protect yourself from the Retis Ransomware you should use standard security practices. This includes using good computing habits and security software. First and foremost, you should always have a reliable and tested backup of your data that can be restored in the case of an emergency, such as a ransomware attack.
You should also have security software that incorporates behavioral detections to combat ransomware and not just signature detections or heuristics. For example, Emsisoft Anti-Malware and Malwarebytes Anti-Malware both contain behavioral detection that can prevent many, if not most, ransomware infections from encrypting a computer.
Last, but not least, make sure you practice the following security habits, which in many cases are the most important steps of all:
- Backup, Backup, Backup!
- Do not open attachments if you do not know who sent them.
- Do not open attachments until you confirm that the person actually sent you them,
- Scan attachments with tools like VirusTotal.
- Make sure all Windows updates are installed as soon as they come out! Also make sure you update all programs, especially Java, Flash, and Adobe Reader. Older programs contain security vulnerabilities that are commonly exploited by malware distributors. Therefore it is important to keep them updated.
- Make sure you use have some sort of security software installed that uses behavioral detections or white list technology. White listing can be a pain to train, but if your willing to stock with it, could have the biggest payoffs.
- Use hard passwords and never reuse the same password at multiple sites.
For a complete guide on ransomware protection, you visit our How to Protect and Harden a Computer against Ransomware article.
%AppData%RANSOM.png (Main Ransom Note)
Retis Registry Keys:
Retis Ransom Note:
Votre bureau, vos photos, vos données et autres dossiers importants ont été chiffrés avec un algorithme fort et une clé unique générés pour cet ordinateur. La clé secrète pour déchiffrer vos données est gardée sur un serveur d'Internet, et personne ne peut déchiffrer vos filchiers jusqu'à ce que vous payez pour l'obtenir. Vous disposez d'un délai de 24 heures pour nous transmettre le paiement. PASSÉ CE DÉLAI VOTRE CLÉ SERA SUPPRIMÉE OE NOS SERVEURS ET IL NE SERA PLUS POSSIBLE POUR VOUS OE RÉCUPÉRER VOS DONNÉES HackLab by Retis
Retis Network Connections: