Cardinal RAT is a potentially low volume remote access trojan (RAT) observed since December 2015. Cardinal RAT is notable for its unique utilization of uncompiled C# source code and the Microsoft Windows built-in csc.exe compiler.[1]
| Domain | ID | Name | Use | |
|---|---|---|---|---|
| Enterprise | T1071 | .001 | Application Layer Protocol: Web Protocols | Cardinal RAT is downloaded using HTTP over port 443.[1] | 
| Enterprise | T1560 | .002 | Archive Collected Data: Archive via Library | Cardinal RAT applies compression to C2 traffic using the ZLIB library.[1] | 
| Enterprise | T1547 | .001 | Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder | Cardinal RAT establishes Persistence by setting the   | 
| Enterprise | T1059 | .003 | Command and Scripting Interpreter: Windows Command Shell | Cardinal RAT can execute commands.[1] | 
| Enterprise | T1140 | Deobfuscate/Decode Files or Information | Cardinal RAT decodes many of its artifacts and is decrypted (AES-128) after being downloaded.[1] | |
| Enterprise | T1573 | .001 | Encrypted Channel: Symmetric Cryptography | Cardinal RAT uses a secret key with a series of XOR and addition operations to encrypt C2 traffic.[1] | 
| Enterprise | T1008 | Fallback Channels | Cardinal RAT can communicate over multiple C2 host and port combinations.[1] | |
| Enterprise | T1083 | File and Directory Discovery | Cardinal RAT checks its current working directory upon execution and also contains watchdog functionality that ensures its executable is located in the correct path (else it will rewrite the payload).[1] | |
| Enterprise | T1070 | .004 | Indicator Removal: File Deletion | Cardinal RAT can uninstall itself, including deleting its executable.[1] | 
| Enterprise | T1105 | Ingress Tool Transfer | Cardinal RAT can download and execute additional payloads.[1] | |
| Enterprise | T1056 | .001 | Input Capture: Keylogging | Cardinal RAT can log keystrokes.[1] | 
| Enterprise | T1112 | Modify Registry | Cardinal RAT sets  | |
| Enterprise | T1027 | .004 | Obfuscated Files or Information: Compile After Delivery | Cardinal RAT and its watchdog component are compiled and executed after being delivered to victims as embedded, uncompiled source code.[1] | 
| .013 | Obfuscated Files or Information: Encrypted/Encoded File | Cardinal RAT encodes many of its artifacts and is encrypted (AES-128) when downloaded.[1] | ||
| Enterprise | T1057 | Process Discovery | Cardinal RAT contains watchdog functionality that ensures its process is always running, else spawns a new instance.[1] | |
| Enterprise | T1055 | Process Injection | Cardinal RAT injects into a newly spawned process created from a native Windows executable.[1] | |
| Enterprise | T1090 | Proxy | Cardinal RAT can act as a reverse proxy.[1] | |
| Enterprise | T1012 | Query Registry | Cardinal RAT contains watchdog functionality that periodically ensures  | |
| Enterprise | T1113 | Screen Capture | Cardinal RAT can capture screenshots.[1] | |
| Enterprise | T1082 | System Information Discovery | Cardinal RAT can collect the hostname, Microsoft Windows version, and processor architecture from a victim machine.[1] | |
| Enterprise | T1033 | System Owner/User Discovery | Cardinal RAT can collect the username from a victim machine.[1] | |
| Enterprise | T1204 | .002 | User Execution: Malicious File | Cardinal RAT lures victims into executing malicious macros embedded within Microsoft Excel documents.[1] |