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Port 445 Details

known port assignments and vulnerabilities
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Port(s) Protocol Service Details Source
445 tcp microsoft-ds TCP port 445 is used for direct TCP/IP MS Networking access without the need for a NetBIOS layer. The SMB (Server Message Block) protocol is used for file sharing in Windows NT/2K/XP and later. In Windows NT it ran on top of NetBT (NetBIOS over TCP/IP, ports 137, 139 and 138/udp). In Windows 2K/XP and later, Microsoft added the possibility to run SMB directly over TCP/IP, without the extra NetBT layer, for this they use TCP port 445.

Microsoft Lync server uses these ports:
444, 445, 448, 881, 5041, 5060 - 5087, 8404 TCP
80, 135, 443, 4443, 8060, 8061, 8080 TCP - standard ports and HTTP(s) traffic
1434 UDP - SQL
49152-57500 TCP/UDP - media ports

Port 445 should be blocked at the firewall level. It can also be disabled by deleting the HKLM\System\CurrentControlSet\Services \NetBT\Parameters\TransportBindName (value only) in the Windows Registry.

Leaving port 445 open leaves Windows machines vulnerable to a number of trojans and worms:
W32.HLLW.Deloder [Symantec-2003-030812-5056-99]
IraqiWorm (aka Iraq_oil.exe )
W32.HLLW.Moega [Symantec-2003-080813-3234-99]
W32.Korgo.AB [Symantec-2004-092415-4853-99] (2004.09.24)
Backdoor.Rtkit.B [Symantec-2004-100115-0426-99] (2004.10.01)
W32.Sasser.Worm [Symantec-2004-050116-1831-99] - exploits port 445 vulnerabilities, opens TCP ports 5554,9996.
Trojan.Netdepix.B [Symantec-2005-011715-5404-99] (2005.01.16.) - trojan uses port 445, opens port 15118/tcp.
Backdoor.IRC.Cirebot [Symantec-2003-080214-3019-99] (2003.08.02) - trojan that exploits the MS DCOM vulnerability, uses ports 445 & 69, opens backdoor on port 57005.
Windows Null Session Exploit.

MS Security Bulletin [MS03-026] outlines a critical RPC vulnerability that can be exploited via ports 135, 139, 445, 593 (or any other specifically configured RPC port). You should filter the above mentioned ports at the firewall level and not allow RPC over an unsecure network, such as the Internet.

See also: Microsoft Security Bulletin [MS03-049] and Microsoft Security Bulletin [MS03-043]

W32.Zotob.C@mm [Symantec-2005-081516-4417-99] (2005.08.16) - 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. Same ports are used by the W32.Zotob.A [Symantec-2005-081415-0646-99] and W32.Zotob.B [Symantec-2005-081415-0741-99] variants of the worm as well.

W32.Zotob.D [Symantec-2005-081609-4733-99] (2005.08.16) - a worm that opens a backdoor and exploits the MS Plug and Play Buffer Overflow vulnerability (MS Security Bulletin [MS05-039]) on port 445/tcp. Connects to IRC servers to listen for remote commands on port 6667/tcp. Also opens an FTP server on port 1117/tcp.

W32.Zotob.E [Symantec-2005-081615-4443-99] (2005.08.16) - a 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 runs and spreads using all current Windows versions, but only infects Windows 2000.
The worm connects to IRC servers and listens for remote commands on port 8080/tcp. It opens port 69/udp to initiate TFTP transfers. It also opens a backdoor on remote compromised computers on port 8594/tcp.

W32.Zotob.H [Symantec-2005-081717-2017-99]

W32.Conficker.worm - a worm with multiple variants. It exploits a buffer overflow vulnerability in the Server Service on Windows computers. McAfee has named the most recently discovered variant of this worm as W32/Conficker.worm.gen.d. The original W32.Conficker.worm attacks port 445, the port that Microsoft Directory Service uses, and exploits Microsoft Windows vulnerability [MS08-067].

Buffer overflow in a certain driver in Cisco Security Agent 4.5.1 before, 5.0 before, 5.1 before, and 5.2 before on Windows allows remote attackers to execute arbitrary code via a crafted SMB packet in a TCP session on port (1) 139 or (2) 445.
References: [CVE-2007-5580] [BID-26723] [SECUNIA-27947] [OSVDB-39521]

LANMAN service on Microsoft Windows 2000 allows remote attackers to cause a denial of service (CPU/memory exhaustion) via a stream of malformed data to microsoft-ds port 445.
References: [CVE-2002-0597] [BID-4532] [OSVDB-5179]
445 tcp Microsoft-DS Active Directory, Windows shares (official) Wikipedia
445 udp Microsoft-DS SMB file sharing (official) Wikipedia
445 tcp trojan Nimda Trojans
445 tcp,udp microsoft-ds Win2k+ Server Message Block SANS
445 tcp microsoft-ds SMB directly over IP Nmap
445 udp microsoft-ds microsoft-ds Nmap
445 tcp threat Netdepix Bekkoame
445 tcp threat Otinet Bekkoame
445 tcp threat Rtkit Bekkoame
445 tcp threat Secefa Bekkoame
445 tcp threat W32.Aizu Bekkoame
445 tcp threat W32.Bobax Bekkoame
445 tcp threat W32.Bolgi.Worm Bekkoame
445 tcp threat W32.Cissi Bekkoame
445 tcp threat W32.Cycle Bekkoame
445 tcp threat W32.Explet Bekkoame
445 tcp threat W32.HLLW.Deborms Bekkoame
445 tcp threat W32.HLLW.Deloder Bekkoame
445 tcp threat W32.HLLW.Gaobot Bekkoame
445 tcp threat W32.HLLW.Lioten Bekkoame
445 tcp threat W32.HLLW.Moega Bekkoame
445 tcp threat W32.HLLW.Nebiwo Bekkoame
445 tcp threat W32.HLLW.Polybot Bekkoame
445 tcp threat W32.Ifbo Bekkoame
445 tcp threat W32.Janx Bekkoame
445 tcp threat W32.Kibuv.Worm Bekkoame
445 tcp threat W32.Kiman Bekkoame
445 tcp threat W32.Korgo Bekkoame
445 tcp threat W32.Mytob Bekkoame
445 tcp threat W32.Reatle Bekkoame
445 tcp threat W32.Sasser Bekkoame
445 tcp threat W32.Scane Bekkoame
445 tcp threat W32.Slackor Bekkoame
445 tcp threat W32.Spybot Bekkoame
445 tcp threat W32.Wallz Bekkoame
445 tcp threat W32.Welchia Bekkoame
445 tcp threat W32.Zotob Bekkoame
445 tcp,udp microsoft-ds Microsoft-DS IANA
39 records found
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Related ports: 135  139  444  593  5554  8594  9996  15118  33333  57005  

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External Resources
SANS Internet Storm Center: port 445

Port numbers in computer networking represent communication endpoints. Ports are unsigned 16-bit integers (0-65535) that identify a specific process, or network service. IANA is responsible for internet protocol resources, including the registration of commonly used port numbers for well-known internet services.
Well Known Ports: 0 through 1023.
Registered Ports: 1024 through 49151.
Dynamic/Private : 49152 through 65535.

TCP ports use the Transmission Control Protocol, the most commonly used protocol on the Internet and any TCP/IP network. 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. Like TCP, UDP is used in combination with IP (the Internet Protocol) and facilitates 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 and realtime gaming, 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 445.
  User Reviews/Comments:
by Mr.A - 2017-08-10 16:14
I liked this website, when Ever I have to do the port lookup I visit this website, the thing I like about is that along with the Port information it also tells us other security related info. which maks my life easier.
by anonymous - 2019-07-30 06:40
This ports also has various SMB exploits ie: eternamblue etc.
by anonymous - 2022-01-05 13:28
There is a typo in the second sentence : verions => versions
by Philip - 2022-01-09 11:38
fixed ty
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