How does CryptoLocker encrypt files?

Inquiring minds want to know: just how does CryptoLocker, the notorious ransomware, encrypt files? Its insidious nature has left many scratching their heads. Could you elaborate on the encryption process it employs? Does it use symmetric or asymmetric cryptography? Are there any known vulnerabilities in its encryption algorithm? Understanding the technical underpinnings of CryptoLocker's encryption methodology is crucial in combating this ever-evolving threat. I'm keen to hear your insights on this perplexing puzzle.