Many factors can affect system security. Open ports on the network are a security risk, allowing hackers to infiltrate via an Internet connection and attack servers and other computers and devices. To find the open ports in the network, a tool like PortScan is necessary.
Find open ports
PortScan scans the network for open ports. The portscanner sends TCP packets to ports of the target computer and waits whether they accept a connection and are therefore open. Closed ports, on the other hand, return an RST packet, and if no response is received, this indicates a packet filter. In addition, there is an FTP and UDP scan to find more open ports.
In addition to the information on open ports of services such as HTTP, SMB, FTP, iSCSI, SMTP, SNMP, MySQL and MongoDB, the system and network scan determines host names and MAC addresses.
Through a scan, one learns, for example, whether port 3389 is open on a Windows computer. This belongs to the Microsoft Remote Desktop Service and allows remote access to a Windows PC. This is why it is interesting as an attack target, especially since it is open by default after the installation of Windows and is often not deactivated by the computer administrator – even if the service is not needed at all. It is similar under Linux with SSH, which should only be activated if you have to access the computer remotely.
Find devices and services
PortScan uses large IP address spaces up to 100 threads and detects many devices on the network during its scan. When searching, the scanner uses the Service Location Protocol (SLP) and finds IPv6 devices, activated UPnP devices, Bonjour services, Netgear routers, Synology’s Network Access Server (NAS) and Buffalo, Epson’s projectors, Samsung’s printers, and MSA’s HP and network devices, as well as Freecom, among others. PortScan then displays the devices and services found in a list.
PortScan not only finds open ports, devices and services, but also provides additional functionality. This includes Whois requests to find out the Internet service providers of IP addresses and domains. Also included are tests of your own Internet speed using uploads and downloads. For domain availability testing, PortScan uses three standardized ping packages in three different sizes and sends each ten times or permanently. The response times then appear in a graphic.
Freeware for Windows
PortScan is a freeware for Windows and can be used for free. The software can be used as portable software from a USB stick and requires no installation.