Adversaries may employ a known symmetric encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Symmetric encryption algorithms use the same key for plaintext encryption and ciphertext decryption. Common symmetric encryption algorithms include AES, DES, 3DES, Blowfish, and RC4.
Detection Strategy for Encrypted Channel via Symmetric Cryptography across OS Platforms
Network Intrusion Prevention: Use intrusion detection signatures to block traffic at network boundaries.