Qu'est-ce que le format de fichier EIUR ?
Un fichier .eiur est un fichier ordinaire qui a été chiffré par le ransomware EIUR, une variante de la famille très répandue STOP/Djvu. Cette souche est apparue vers la mi-2022 et se comporte comme ses nombreux frères, différant principalement par l'extension de quatre lettres qu'elle ajoute. Lorsqu'EIUR infecte un PC Windows, il brouille les documents, photos, bases de données et vidéos avec le chiffrement Salsa20, protège cette clé avec RSA-2048 et renomme chaque fichier de sorte que budget.xlsx devient budget.xlsx.eiur. Il dépose ensuite une demande de rançon nommée _readme.txt dans chaque dossier concerné, réclamant « 980 $ » en Bitcoin (ou « 490 $ » sous 72 heures) et listant les adresses de contact [email protected] et [email protected].
Pour agir rapidement, le malware ne chiffre que les premiers 150 Ko de chaque fichier, c'est pourquoi les fichiers volumineux sont parfois partiellement intacts. La présence de fichiers .eiur signifie que le ransomware a été exécuté sur votre machine et qu'il a pu installer un cheval de Troie voleur de mots de passe en plus du chiffreur.
Sécurité et sûreté
RISQUE : HIGHA .eiur file is itself inert ciphertext, but its presence means active ransomware ran on the machine and may still be resident along with a bundled information-stealer such as RedLine or Vidar. Do not pay the ransom; there is no guarantee of a key and payment funds further attacks. Isolate the device, run a reputable anti-malware scan to remove the executable, then attempt recovery only from backups or the Emsisoft decryptor.
Détails du format
en brefProgrammes qui ouvrent les fichiers EIUR
Windows5 apps
Emsisoft Decryptor for STOP Djvu
Gratuit Download and run the decryptor, let it scan your drives, and it will restore files that were encrypted with a known offline key; it reports when an online key was used and files cannot be recovered.
Malwarebytes
Freemium Run a full scan to detect and quarantine the EIUR ransomware executable and any bundled stealer before attempting any file recovery.
Windows System Restore
Intégré Roll the system back to a restore point created before the infection to recover unencrypted copies, if restore points survived the attack.
ShadowExplorer
Gratuit Browse Volume Shadow Copies to pull earlier, unencrypted versions of files, though STOP/Djvu usually deletes shadow copies.
PhotoRec
Open-source Carve deleted original files from the disk after encryption, since STOP/Djvu often encrypts a copy and deletes the source, leaving recoverable remnants. Détails techniques
spécifications approfondies| Encoding | Salsa20 stream cipher applied to file contents |
| Encryption | Salsa20 for data; the Salsa20 key is protected with RSA-2048. Each victim receives either a shared 'offline' key (used when the C2 server is unreachable) or a unique 'online' key fetched from the attacker server. |
| Byte order | N/A (opaque ciphertext) |
| Container | Original file wrapped with encrypted payload plus an appended block containing the encryption marker and victim key/ID data |
| Partial Encryption | Only the first 150 KB of each file is encrypted, which is why large files are sometimes partially recoverable or repairable |
| Typical size | Same as the original file plus a small appended overhead |
| Structure | Original data encrypted in-place at the start of the file, with a trailing signature and embedded key/personal-ID block; the '.eiur' extension is appended to the original filename (for example 'photo.jpg' becomes 'photo.jpg.eiur'). |
| Integrity | None; no integrity field is present |
| Ransom Note | _readme.txt dropped in every folder with encrypted files and on the desktop |
| Ransom Amount | USD 980, reduced to USD 490 if the victim contacts the attackers within 72 hours, payable in Bitcoin |
| Attacker Contacts | [email protected] and [email protected] |
| Malware Family | STOP/Djvu ransomware |
| Platforms | Windows |
| Notes | EIUR spreads through cracked software, key generators, fake installers and malicious downloads, and often bundles a secondary information-stealer (such as RedLine or Vidar). Files encrypted with a known offline key can sometimes be recovered with Emsisoft's free decryptor; files encrypted with a unique online key cannot be decrypted without the attacker's private key. |
| Publié | 2022 (STOP/Djvu variant appeared around late June 2022) |
Conversions EIUR
Q&R de la communauté
posées par les utilisateursPas encore de questions - soyez le premier à poser une question sur les fichiers EIUR.
