File Transfer Protocols
Where this stands
One published detection covers this technique. Every one is unverified — no rule on Siemphony has been executed against real telemetry.
What the technique is
Adversaries may communicate using application layer protocols associated with transferring files to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server. Protocols such as SMB, FTP, FTPS, and TFTP that transfer files may be very common in environments. Packets produced from these protocols may have many fields and headers in which data can be concealed. Data could also be concealed within the transferred files. An adversary may abuse these protocols to communicate with systems under their control within a victim network while also mimicking normal, expected traffic.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN1169
Detects FTP, SMB, or TFTP traffic initiated by suspicious processes like PowerShell, cmd.exe, or rundll32.exe—especially with large outbound file transfers or unbalanced traffic volume.
- AN1170
Detects usage of FTP, SCP, or TFTP by non-interactive shells or automation scripts transferring large data volumes to untrusted IPs.
- AN1171
Detects Automator, AppleScript, or Terminal executing curl, lftp, or TFTP for binary transfer to untrusted IPs or unusual ports.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.