Scanning Networks with zmap
Today, while browsing Bilibili, I came across a video introducing zmap as a network scanning tool. It seemed very interesting, so I quickly downloaded it to try it out. On a whim, I decided to scan my campus network to see if anyone was using the Clash proxy on port 7890.
zmap -p 7890 10.78.0.0/15After running the command above, I actually managed to discover several IP addresses!
10.79.11.174
10.78.161.150
10.78.77.92
10.78.186.4
10.78.71.72
10.78.19.209
10.79.155.62
10.79.17.43
10.78.43.125
10.78.58.53
10.78.30.112
...Unauthorized Proxy Use
The reason these IPs can be discovered using zmap is that the target machines allow connections from other IPs. In other words, their firewalls are disabled, and Clash is listening on 0.0.0.0:7890. By configuring the network proxy on Windows to IP:7890, you can effectively "borrow" someone else's proxy traffic. (However, this is not recommended and is unethical.)
Configuration and Usage
After configuring your system like this, you can access the internet through the external proxy, even if your own Clash is turned off.
