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Ransomware without ransom notes and extension of encrypted files

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#1 see2323


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Posted 10 May 2017 - 09:29 AM

Hi all,


My files on my laptop are probably encrypted by some ransomware.


But the weird things are there are no ransom notes I could find and the extension of the encrypted files are not changed.


I have uploaded the encrypted files to ID RANSOMWARE but there was no found type.



Please find the sample files below:




Files with (encrypted) are corrupted files. The another one is the backup file.



Please tell If you might need more sample files.


I am looking forward to your reply. Thank you very much.

Edited by see2323, 10 May 2017 - 09:29 AM.

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#2 quietman7


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Posted 10 May 2017 - 10:46 AM

There are several ransomware infections that do not append an obvious extension to the end of encrypted filenames or add a known file pattern (filemarker) which helps to identify it. CryptoWall, CrypMic, DMA Locker, Microsoft Decryptor (CryptXXX), PClock, Spora, Cryptofag, TeslaCrypt v4.0, CryptoHost, MotoxLocker, KawaiiLocker, Hermes, LoveServer and Power Worm do not append or change file extensions.

Some ransomware variants (i.e. DMA Locker, TeslaCrypt, CrypMic) will add a unique hex pattern (filemarker) identifier in the header of every encrypted file so the ransomware can identify the file as one it encrypted. Spora-encrypted files utilize a 4 byte long Crc32 file marker. CryptoWall is identified by how the files are renamed. CryptoWall 3.0 and 4.0 encrypted files typically will have the same 16 byte header which is different for each victim. PClock and Cryptofag do not use a filemarker.

The best way to identify the different ransomwares that do not append an extension is the ransom note (including it's name), samples of the encrypted files, the malware file itself or at least information related to the email address used by the cyber-criminals to request payment.

Based on current infection rates and statistics, PClock is the most prevalent ransomware variant that does not change the extension or leave a filemarker. Unfortunately, newer PClock variants are not decryptable...there is no longer any way to provide decryption without paying the ransom.
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