Adversaries may encode data with a standard data encoding system to make the content of command and control traffic more difficult to detect. Command and control (C2) information can be encoded using a standard data encoding system that adheres to existing protocol specifications. Common data encoding schemes include ASCII, Unicode, hexadecimal, Base64, and MIME.(Citation: Wikipedia Binary-to-text Encoding)(Citation: Wikipedia Character Encoding) Some data encoding systems may also result in data compression, such as gzip.
Behavior-chain detection for T1132.001 Data Encoding: Standard Encoding (Base64/Hex/MIME) across Windows, Linux, macOS, ESXi
Network Intrusion Prevention: Use intrusion detection signatures to block traffic at network boundaries.