Che cos'è il formato di file EIUR?
Un file .eiur è un file ordinario che è stato crittografato dal ransomware EIUR, una variante della diffusa famiglia STOP/Djvu. Questo ceppo è apparso intorno alla metà del 2022 e si comporta come i suoi numerosi simili, differendo principalmente per l'estensione di quattro lettere che aggiunge. Quando EIUR infetta un PC Windows, cifra documenti, foto, database e video con il cifrario Salsa20, protegge tale chiave con RSA-2048 e rinomina ogni file in modo che budget.xlsx diventi budget.xlsx.eiur. Successivamente, rilascia una richiesta di riscatto chiamata _readme.txt in ogni cartella interessata, richiedendo «$980» in Bitcoin (o «$490» entro 72 ore) e indicando gli indirizzi di contatto [email protected] e [email protected].
Per agire rapidamente, il malware crittografa solo i primi 150 KB di ogni file, motivo per cui i file di grandi dimensioni sono talvolta parzialmente intatti. La presenza di file .eiur indica che il ransomware è stato eseguito sulla macchina e potrebbe aver installato un trojan per il furto di password insieme al modulo di crittografia.
Sicurezza e incolumità
RISCHIO: 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.
Dettagli del formato
in sintesiProgrammi che aprono file EIUR
Windows5 apps
Emsisoft Decryptor for STOP Djvu
Gratuito 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
Integrato Roll the system back to a restore point created before the infection to recover unencrypted copies, if restore points survived the attack.
ShadowExplorer
Gratuito 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. Dettagli tecnici
specifiche approfondite| 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. |
| Rilasciato | 2022 (STOP/Djvu variant appeared around late June 2022) |
Conversioni EIUR
Domande e risposte della community
chiesto dagli utentiAncora nessuna domanda - sii il primo a chiedere informazioni sui file EIUR.
