Peter Saint-Andre wrote:
On 11/25/09 11:53 AM, Jesse Thompson wrote:Peter Saint-Andre wrote:I think that the key for the 'right/best' anti-SPAM XMPP solution is to involve regular/polite XMPP users in any way.I have my doubts that normal users will bother to flag messages as spam. However, given that I have only ever received a few spam messages over XMPP (and even those I wasn't 100% sure about), perhaps it would not be such a huge burden.I like the idea of account level reputation. The current, most troublesome, battlefront on the war against email spam is dealingspammer-created freemail accounts,Most of the large, public XMPP IM services essentially offer "freechat" accounts. The use of CAPTCHAs at, e.g., jabber.org is a small hurdle.
CAPTCHAs won't stop them from creating accounts. Take a look at this list of email "phishing reply dropbox" email addresses that we have been collecting over the past year or two.
https://aper.svn.sourceforge.net/svnroot/aper/phishing_reply_addresses
and with phished account credentials on closed systems.I think we've seen less of this on the XMPP network because we don't have very good web integration.
No, the phishers just ask the users to reply via email with their account credentials. The link above is a list of these reply destination email accounts.
Or, they put up a web form somewhere.You would be surprised how many users will give away their credentials to anyone that asks.
You could apply an account-level reputation system at the server as well as the client. An XMPP operator could set up the server to block domains whose trustworthy account ratio is below their tolerance level. This would effectively block domains that have only spammers. But it would not block domains like jabber.org or gmail that are trustworthy but have spammers signing up for free accounts.Agreed.For spamming accounts in trustworthy domains, the server operator could set it up to block accounts that meet a certain untrustworthinessthreshold.So when mydomain.com receives an inbound stanza from [email protected], it would check the trust score of the sender?
yeah
Or, the users could do it at the client level.That seems like more work. See above about user laziness. :)
My thought was more that ambitious developers will be more able to integrate it into the clients before it is adopted into server software and deployed by the operators. Think of it as a way to bridge the gap.
Anti-spam scanning was built into email clients well before it became common on the server-side (around 2002.) Once the servers caught up, the client approach became less effective, but it is still useful in some situations.
The key is to figure out how to collect and expose the data in a private way.Your thoughts are welcome. Do you mean the scores need to be private, or the source data needs to be private?
I was initially thinking of a trust network: I trust someone who is trusted by the people I trust. I could then set it up so that people who are very trustworthy are allowed to send me anonymous messages and I will auto-authorize into my roster, someone who is completely foreign to my trust network is blocked from sending messages, and various levels in between.
Some of this data is already available within the server roster databases, but otherwise it would have to be fed by opt-in contributers. The problem with this trust network approach is that the data could be mined by spammers and phishers, so it would need to be kept private somehow.
Otherwise, traditional DNSBLs (specifically, URIBLs of JIDs) are the way to go. It might be possible to work with the existing DNSBL providers to create a new blacklist of JIDs.
Jesse -- Jesse Thompson Division of Information Technology, University of Wisconsin-Madison Email/IM: [email protected]
smime.p7s
Description: S/MIME Cryptographic Signature
