Skip to content

Proxy Abuse

An open proxy is a proxy server that will accept client connections from any IP address and make connections to any Internet resource. Abuse of open proxies is currently implicated in a significant portion of e-mail spam delivery. Spammers frequently install open proxies on unwitting end-users’ Microsoft Windows computers by means of computer viruses designed for this purpose. Internet Relay Chat (IRC) abusers also frequently use open proxies to cloak their identities.

Because proxies could be implicated in abuse, system administrators have developed a number of ways to refuse service to open proxies. IRC networks such as the Blitzed network automatically test client systems for known types of open proxy. Likewise, an email server may be configured to automatically test e-mail senders for open proxies, using software such as Michael Tokarev’s proxy check.

Groups of IRC and electronic mail operators run DNSBLs publishing lists of the IP addresses of known open proxies, such as Blitzed OPM and CBL.

The ethics of automatically testing clients for open proxies are controversial. Some experts, such as Vernon Schryver, consider such testing to be equivalent to an attacker portscanning the client host. Others consider the client to have solicited the scan by connecting to a server whose terms of service include testing.

Related Articles

Related Articles

All
  • All
  • Easy Prey Podcast
  • General Topics
  • Home Computing
  • IP Addresses
  • Networking
  • Online Privacy
  • Online Safety

SIM Swapping. Scammers are taking over our smartphones…and text messages too!

Did you know that through a dirty trick called SIM swapping, a scammer could take over your…

[Read More]
WELCOME

About the Website Redesign

I hope you like the WhatIsMyIPAddress.com redesign and how we’ve improved the website for you. The IP…

[Read More]
Twitter Hack

Twitter Hack Lessons: Employees Often Help Hackers Succeed.

There was huge hack of Twitter in Summer of 2020. with all kinds of surprises. Here’s what…

[Read More]
FREE VPN

A Free VPN is Always Better Than Not Using One

A free VPN (a trustworthy one) may be all that you need for more privacy, more security…

[Read More]

Tech Tips So You Can Be the Final Girl

Imagine you’re in your favorite slasher flick. You are on the run from Michael Myers or Jason….

[Read More]

How to Stay Entertained While Self-Isolating During the Coronavirus Crisis

So you’re self-isolating while trying to balance work, home, and in some cases school all under one…

[Read More]