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Port 33333 Details

known port assignments and vulnerabilities
threat/application/port search:
Port(s) Protocol Service Details Source
33333 tcp trojans W32.Zotob.C@mm (2005.08.16) - a mass-mailing worm that opens a backdoor and exploits the MS Plug and Play Buffer Overflow vulnerability (MS Security Bulletin [MS05-039]) on port 445/tcp. It connects to IRC servers and listens for remote commands on port 8080/tcp. It also opens an FTP server on port 33333/tcp.
Note: Same ports are used by the W32.Zotob.A and W32.Zotob.B variants of the worm as well.

Backdoor.Selka (2004.11.12) - backdoor program, can affect all current Windows versions. Listens on port 33333.

Some older trojans/backdoors that also use this port: Blakharaz, Prosiak

Port is IANA registered for Digital Gaslight Service.
33333 tcp trojan [trojan] Prosiak Trojans
33333 tcp Blakharaz [trojan] Blakharaz SANS
33333 tcp Prosiak [trojan] Prosiak SANS
33333 tcp threat Selka Bekkoame
33333 tcp threat W32.Zotob Bekkoame
33332-33433 tcp,udp Unassigned IANA
7 records found
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External Resources
SANS Internet Storm Center: port 33333

Well Known Ports: 0 through 1023.
Registered Ports: 1024 through 49151.
Dynamic/Private : 49152 through 65535.

TCP ports use the Transmission Control Protocol. TCP is the most commonly used protocol on the Internet and any TCP/IP network. Whereas the IP protocol deals only with packets, TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and that packets will be delivered in the same order in which they were sent. Guaranteed communication/delivery is the key difference between TCP and UDP.

UDP ports use the Datagram Protocol, a communications protocol for the Internet network, transport, and session layers. Like TCP (Transmission Control Protocol), UDP is used with IP (the Internet Protocol) and makes possible the transmission of datagrams from one computer to applications on another computer, but unlike TCP, UDP is connectionless and does not guarantee reliable communication; it's up to the application that received the message to process any errors and verify correct delivery. UDP is often used with time-sensitive applications, such as audio/video streaming, where dropping some packets is preferable to waiting for delayed data.

When troubleshooting unknown open ports, it is useful to find exactly what services/processes are listening to them. This can be accomplished in both Windows command prompt and Linux variants using the "netstat -aon" command. We also recommend runnig multiple anti-virus/anti-malware scans to rule out the possibility of active malicious software. For more detailed and personalized help please use our forums.

Please use the "Add Comment" button below to provide additional information or comments about port 33333.
  User Reviews/Comments:
by anonymous - 2016-09-26 04:29
Port 33333 may be used by the GoodSync app. It may also be activated through UPnP. See
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