What is a proxy?
A proxy is a piece of software that allows a user to access internet through a different computer (taking on the IP adress of this computer). This can allow access to the internet from networks which do not have a direct internet connection.
So why aren’t they allowed?
We do not have a problem with correctly configured proxies, they are sometimes the only way for someone to gain internet access. However when a proxy is misconfigured to allow access to anyone on the internet (often called an open proxy), it can be used by anyone to connect through your system!
This type of misconfigured proxy is an annoyance to the internet community as a whole because they allow abusers to hide behind someone else’s IP address.
This can be abused by spammers to anonymously send unsolicitied email (“spam”), to anonymously connect to (and possibily abuse) a chat network such as IRC or to access websites.
How does this affect IRC?
If you have been on IRC for any length of time, you have probably seen an attack using open proxies at least once. Hundreds of clients will enter a channel, often with random nick names, and start sending large amounts of coloured channel and CTCP messages. Commonly they will leave and join the channel rapidly in order to cause more disruption.
Without completely locking up the channel, there is no effective way to stop the flood. Even if the channel is locked up, the floods of text can be sent to individual users and this will usually be enough to disconnect them.
Most of these types of attacks use open proxies because open proxies are relatively easy to come by. Lists of them are readily available over the Internet. So this is why many IRC networks do not allow them. If you have to use a proxy, it should be configured correctly.
How can I fix it?
There are many different types of proxy software, in all cases you need to make sure that your proxy is configured to only allow the IP addresses within your own network to access it. A proxy that does not allow external access is considered secure.
If you are not using any kind of proxy software then it is likely a trojan or virus has infected your system. We recommend you perform a full virus scan with up-to-date virus definitions. If you do not have a virus scanner try AVG Anti-Virus Free.
If you are certain you do not have an open proxy or virus it is possible your IP address is on a list of previously comprimised machines (known as a DNS Blacklist). It is also possible your host will have automatically been submitted to one or more of these lists when you connected with an open proxy. If you cannot resolve this problem please contact us via firstname.lastname@example.org with your ban ID and we’ll try and help you.
How do we check for them?
When you connect to SorceryNet we ask your system to connect to one of our servers which a correctly configured proxy would not allow. If your system responds OK to this request we know it’s not configured properly and as a result the proxy will be blocked from connecting to SorceryNet. This is for your own protection too as a bad person could instruct the proxy to do things you wouldn’t want to happen.
We scan for proxies from the IP subnets below so you can be sure any connections from these IPs are safe and you should not worry if your router detects this as an attack, it’s not, honest!
1) 18.104.22.168 (open.proxy.monitor.sorcery.net)
If you disagree with us checking for these security measures please disconnect from SorceryNet.