TCP Port 8333
About TCP Port 8333
Port 8333 sits outside of IANA’s formally registered assignments. Ports in this numerical range can be assigned by IANA but this specific port has no current registration. It is referenced in 2049 IDS rules and exhibits moderate malware activity indicators. Ports outside formal IANA assignment are commonly used by malware authors and security tooling.
IDS Rule References
2049 IDS / security rules reference TCP port 8333. Treat that number as context, not a danger score. Many detection rules are written against groups of ports rather than one service, web ports especially, so common web alternate ports inherit large counts while genuinely sensitive services can show few rules or none. Presence in IDS rules does not mean traffic on this port is malicious.
Rule categories (top 6): trojan-activity (730), web-application-activity (476), web-application-attack (344), attempted-recon (270), misc-activity (76), attempted-user (58).
Sample rule descriptions for TCP port 8333:
- SERVER-WEBAPP PCCS mysql database admin tool access
- SERVER-WEBAPP HyperSeek hsx.cgi directory traversal attempt
- SERVER-WEBAPP SWSoft ASPSeek Overflow attempt
- SERVER-WEBAPP Progress webspeed access
- SERVER-WEBAPP yabb directory traversal attempt
Malware Rule References
A meaningful share of the IDS rules that reference this port are malware related.
684 of the 2049 IDS rules that reference TCP port 8333 are malware related. That describes detection coverage across the whole internet, not anything about your machine or your network.
Families observed (top 8): Bancos (20), Fareit (15), Zeus (15), DesertFalcon (11), Symmi (11), Zebrocy (11), Chopper (10), Locky (9), and 263 more families.
Data Sources
This information is compiled from: Emerging Threats Open Ruleset (BSD 2-Clause / GPLv2 per SID range), Snort Community Rules (GPLv2), and MITRE ATT&CK (Apache 2.0).