The criminals have made changes and started using proper asymmetrical encryption in newer STOP versions beginning with .coharos, .gero, .hese, .geno, .seto, .peta, .meds, .moka, .kvag, .domm, etc. Unfortunately, these new versions are not decryptable without paying the ransom and obtaining the private keys from the criminals who created the ransomware.
This means...There no longer is any method to get OFFLINE KEYS for many of these newer variants and no way to decrypt files if infected with an ONLINE KEY without paying the ransom and obtaining the private keys from the criminals who created the ransomware. However, experts are working on ways to obtain OFFLINE KEYS and if they are able to do so, that information will be provided in the support topic
Emmanuel_ADC-Soft, a Support Service Manager for ADC-Soft and partner with Dr.Web has indicated the .gero, .hese, .meds, .moka, .kvag, .peta variants can be decrypted if they were encrypted with an OFFLINE KEY. See Post #7561 and Post #7612 for instructions.
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