Ask HN: Good web service to detect proxied IP addresses?

4 points·barmstrong··7 comments

Hi,

I'm getting a large number of scam/spam messages being sent to users on my site. I have the usual deterrents in place (captchas, etc) but was wondering if there is a good API out there I can query to see if a user's IP address is being proxied or if they are known scammers/spammers/bad people from their ip address.

Thanks!

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I don't know any services, but this might be a good place to start looking: http://whatismyipaddress.com/blacklist-check.

There are a number of links to various IP blacklist providers.

Yep, great place to start. Thanks!

Well behaving proxy servers will send X-Forwarded-For and other extra headers along with the request. Maybe the spammers actually use zombie machines (that don't send this), but worth checking at least.

Most individual spammers do at least one thing that makes it easy to identify them. Maybe they submit forms 10x faster than any human? Maybe no referer? A unique user agent?

I wrote a script that runs every 15 minutes and checks the IPs of new users against Stop Forum Spam's API here:

http://www.stopforumspam.com/apis

It's caught the significant majority of spammers, giving me some time to write other spam protection checks.

you can probably sign up for and integrate with Akismet's API and that can help quite a bit.

Yep I think comment spam on blogs has a slightly different profile than private messages being sent to users, but their service may catch a lot of it anyway. Will investigate this option. Thanks!

spam is spam though. everything has a footprint, and systems like akismet can detect those.

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