37C3 - Unlocked! Recovering files taken hostage by ransomware

Security

Recover files taken hostage by ransomware - learn about the inner workings of cryptomalware and how to decrypt files using symmetric and asymmetric cryptography techniques.

Key takeaways

Ransomware gangs are getting more efficient in their attacks, using cryptography and sophisticated malware.
The file size of 5,000 bytes is a common threshold for full-encryption.
Key points: symmetric cryptography is used for file encryption asymmetric cryptography (RSA or ECC) is used for key generation victim-specific key generation helps to prevent decryption victims may be able to recover their files by XORing unknown plaintext with the keystream.
The author hopes to spread awareness and prevent future incidents.
Some organizations have fallen victim to ransomware attacks, and the author suggests having backups as a solution.
The importance of responsible IT security and patch management is highlighted.
Law enforcement agencies and incident responders can provide valuable assistance in dealing with ransomware attacks.
Efficient decryption methods can be used to recover encrypted files.
The author invites the audience to try recovering encrypted samples from GitHub.
Some victim-specific information was shared, including the XOR operation’s ability to reverse.
The event showed how to decrypt files taken hostage by ransomware.
Specific event information: Hosted at 37C3 The author, Tobias, is a German free software advocate The talk focused on recovering files taken hostage by ransomware.

37C3 - Unlocked! Recovering files taken hostage by ransomware

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