![Tcp redirector](https://loka.nahovitsyn.com/188.jpg)
![tcp redirector tcp redirector](https://securityonline.info/wp-content/uploads/2017/06/iptables-packet-flow-ng-928x413.png)
Tcp redirector portable#
We also needed to integrate the capability with multiple C2 frameworks, so any mechanism for implementing in-memory execution should be portable across various C2 frameworks. Furthermore, we wanted to execute the tool entirely in memory with a minimum on-disk footprint. We wanted a tool that we could run for a short period to redirect traffic without rebooting and then subsequently stop redirecting traffic after performing an attack. Therefore, this option, while viable, was not sufficient for our requirements. However, we typically try to avoid making any permanent system changes or modifications during red team operations (and avoid rebooting production systems). Īnother option we considered was disabling SMB services on the host and rebooting.
Tcp redirector windows#
Francisco Dominguez also notes this limitation of the “NetSh PortProxy” interface in his article titled “Remote NTLM relaying through meterpreter on Windows port 445”. However, in this case, it appears that this mechanism doesn’t work for redirecting traffic destined for the SMB service running on port 445/TCP. Our initial attempt at performing SMB relaying through Cobalt Strike attempted to use the “NetSh PortProxy” mechanism to redirect traffic destined for port 445/TCP. Methods for Performing SMB Relaying on Windows We have also included a feature in PortBender which allows an attacker to simulate the PortServ.sys persistence technique leveraged by the Duqu 2.0 threat actor. For example, a user may wish to modify traffic destined for the 445/TCP port to 8445/TCP. To overcome this operational hurdle, we have developed a custom utility named “PortBender” which allows us to redirect traffic from an incoming TCP port to an alternative TCP port. Unfortunately, in previous scenarios, we have been primarily limited to passive credential collection and unable to perform relaying attacks when obtaining credentials through SMB. Furthermore, it is not uncommon for our team to perform name resolution poisoning during red team engagements to harvest credentials within an environment. Often, we need to perform this attack from a compromised Windows system where the built-in SMB service is already listening on port 445/TCP. Colloquially we often refer to this as a “Computer AdminTo Computer” vulnerability.Įxploiting this issue in practice during a red team engagement has often historically been difficult. You can use iptables for this type of redirection too but if you can’t use iptables for any reason, it is possible to use transproxy support any port you want like that: redir -transproxy 1.1.1.In a previous article titled “ Active Directory Computer Account SMB Relaying Attack,” we discussed how an attacker could leverage computers assigned administrative rights to other computers to escalate privileges or move laterally using the printer spooler service.
![tcp redirector tcp redirector](https://media.pcwin.com/images/screen/75732-bill_redirect_serial_file_tcp_port___kb.gif)
Redir also has a transparent proxy feature. Setting other ip addresses will make no sense. Local address specified with -laddr should be one of the ip addresses that we can access our redirecting system. We have to run redir such as below to do so: redir -laddr=1.1.1.1 -lport=80 -caddr=2.2.2.2 -cport=8080 Simply, we want redir utility to redirect connections coming to 1.1.1.1 on port 80 to 2.2.2.2 port 8080. Suppose that the ip address of our system is 1.1.1.1 and we would like to redirect all the traffic which coming from port 80 to a remote server with ip address of 2.2.2.2 and port 8080. To redirect TCP connections with redir utility, simply type the command such as below: redir -laddr= -lport= \ It’s functionally basically consists of the ability to listen for TCP connections on a given port, and when it recieves a connection, to then connect to a given destination address/port, and pass data between them.
![Tcp redirector](https://loka.nahovitsyn.com/188.jpg)