IMPORTANT: No additional bug fixes or documentation updates will be released for this version.
Detects events that may indicate the use of FTP network connections to the Internet. The File Transfer Protocol (FTP) has been around in its current form since the 1980s. It can be a common and efficient procedure on your network to send and receive files. Because of this, adversaries will also often use this protocol to exfiltrate data from your network or download new tools. Additionally, FTP is a plain-text protocol which, if intercepted, may expose usernames and passwords. FTP activity involving servers subject to regulations or compliance standards may be unauthorized.
Rule type: query
Risk score: 21
Runs every: 5 minutes
Maximum signals per execution: 100
Version: 3 (version history)
Added (Elastic Stack release): 7.6.0
Last modified (Elastic Stack release): 7.7.0
FTP servers should be excluded from this rule as this is expected behavior. Some business workflows may use FTP for data exchange. These workflows often have expected characteristics such as users, sources, and destinations. FTP activity involving an unusual source or destination may be more suspicious. FTP activity involving a production server that has no known associated FTP workflow or business requirement is often suspicious.
network.transport:tcp and destination.port:(20 or 21) and source.ip:(10.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16) and not destination.ip:(10.0.0.0/8 or 127.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16 or "::1")
Framework: MITRE ATT&CKTM
- Name: Command and Control
- ID: TA0011
- Reference URL: https://attack.mitre.org/tactics/TA0011/
- Name: Commonly Used Port
- ID: T1043
- Reference URL: https://attack.mitre.org/techniques/T1043/
- Name: Exfiltration
- ID: TA0010
- Reference URL: https://attack.mitre.org/tactics/TA0010/
- Name: Exfiltration Over Alternative Protocol
- ID: T1048
- Reference URL: https://attack.mitre.org/techniques/T1048/
- Version 3 (7.7.0 release)
Updated query, changed from:
network.transport: tcp and destination.port: (20 or 21) and ( network.direction: outbound or ( source.ip: (10.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16) and not destination.ip: (10.0.0.0/8 or 172.16.0.0/12 or 192.168.0.0/16) ) )
- Version 2 (7.6.1 release)
- Removed auditbeat-*, packetbeat-*, and winlogbeat-* from the rule indices.