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Background

I researched a detection of spam sent out using bots. After studying different techniques used by bots to deliver spam, I have no generalised solution to detect spamming at the source network (where bots are residing) in different scenarios (Ex:Using Mx record to directly spam the destined mail-server, using open relays, using webmail services, using open proxy, using spoofed IP address). So, I moved to a receiver level, where all mails are delivered because at receiver side we simply have to say if a mail was a spam or legitimate one, according to some heuristics.

Query

However, could anyone suggest some generalized approach to detect spamming at source network and if possible provide some remarks which would be good, detecting spam mails at the receiver side or the spamming at the source network, where all bots reside?

techraf
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user10012
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    I won't give you a full answer to this one but I just wanted to make sure that you're aware that all bots don't reside at the same place and there is spam sent from **millions** of computers worldwide. Look at how existing spam detection scripts like SpamAssassin work and read on the most popular black lists which often tend to explain the process they use to rate the sender. The only source detection you can and should do is for messages sent from your MTA. – Julie Pelletier Jul 01 '16 at 17:29
  • ok,got it,you are talking about receiver side,i have one question ,is it possible to know at the receiver side,whether spam is sent using open relay or open proxy or bots? – user10012 Jul 01 '16 at 17:34
  • @user10012, Can you please clarify, are you only interested in detecting spam sent out of one particular network, where you control the Source routers? Or are you trying to detect spam sent worldwide to your Receiver equipment? – 700 Software Jul 01 '16 at 17:34
  • @GeorgeBailey, yes i mean detecting spam sent out of one particular network,supposing that they are lots of email spambots residing. – user10012 Jul 01 '16 at 17:37
  • @user10012: Your MTA knows the MTA that sent the message and an open relay is an MTA that accepts delivery for emails from anyone to anyone else. That can be quite easily tested but doing so live on an MTA might cause it a serious overload. – Julie Pelletier Jul 01 '16 at 17:37
  • @user10012: Note that some spammers are much more knowledgeable on the subject and much better equipped with muliple (hundreds or thousands) of IPs, proxys, etc. – Julie Pelletier Jul 01 '16 at 17:39
  • @JuliePelletier well,as you mentioned that only if my MTA is involved,i can do detection at source and detecting whether spam is sent out specifically by bots has no standard method,So,i guess detection at receiver side is better.Is this the right interpretation? – user10012 Jul 01 '16 at 17:47
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    @user10012: When analyzing for spam, you should take all the methods you can that don't overload your server. There are multiple organizations that analyze email delivery patterns and that you should refer to. Rejecting mail from an open relay is common practice and they are likely almost all listed in existing black lists. – Julie Pelletier Jul 01 '16 at 18:01
  • I do not understand what actions you are trying to protect against. Are you concerned with clients on your network spamming users on your network? If not, how can you exchange source and destination filtering? Source filtering can be used for outgoing emails and destination for incoming. – Neil Smithline Jul 01 '16 at 20:43
  • @NeilSmithline, I want to detect the spam bots which are inside my network and sending spam to users outside my network using different techniques(using open relays, using webmail services, using open proxy, using spoofed IP address).So i wish if it's possible to detect the spam bots using a generalized way that could cover all scenarios(as they are using several techniques to spam.) – user10012 Jul 02 '16 at 12:08
  • Well if your company had a mail server, mail.whatever.com. Then all legit clients should connect to it, and have it send your emails. Then if random PC starts to establish a outbound connection to ports 25,443,993, or etc for any other than mail.whatever.com then A. block them, and B. Send a red alert that they are infected. – cybernard Jul 07 '16 at 01:01

1 Answers1

-1

It's a classic for a reason:

Your post advocates a

(X) technical ( ) legislative ( ) market-based ( ) vigilante

approach to fighting spam. Your idea will not work. Here is why it won't work. (One or more of the following may apply to your particular idea, and it may have other flaws which used to vary from state to state before a bad federal law was passed.)

( ) Spammers can easily use it to harvest email addresses
( ) Mailing lists and other legitimate email uses would be affected
( ) No one will be able to find the guy or collect the money
( ) It is defenseless against brute force attacks
( ) It will stop spam for two weeks and then we'll be stuck with it
( ) Users of email will not put up with it
( ) Microsoft will not put up with it
( ) The police will not put up with it
(x) Requires too much cooperation from spammers
( ) Requires immediate total cooperation from everybody at once
( ) Many email users cannot afford to lose business or alienate potential employers
( ) Spammers don't care about invalid addresses in their lists
( ) Anyone could anonymously destroy anyone else's career or business

Specifically, your plan fails to account for

( ) Laws expressly prohibiting it
(x) Lack of centrally controlling authority for email
(x) Open relays in foreign countries
( ) Ease of searching tiny alphanumeric address space of all email addresses
(x) Asshats
( ) Jurisdictional problems
( ) Unpopularity of weird new taxes
( ) Public reluctance to accept weird new forms of money
( ) Huge existing software investment in SMTP
( ) Susceptibility of protocols other than SMTP to attack
( ) Willingness of users to install OS patches received by email
(x) Armies of worm riddled broadband-connected Windows boxes
( ) Eternal arms race involved in all filtering approaches
( ) Extreme profitability of spam
( ) Joe jobs and/or identity theft
( ) Technically illiterate politicians
( ) Extreme stupidity on the part of people who do business with spammers
(x) Dishonesty on the part of spammers themselves
( ) Bandwidth costs that are unaffected by client filtering
( ) Outlook

and the following philosophical objections may also apply:

( ) Ideas similar to yours are easy to come up with, yet none have ever
been shown practical
( ) Any scheme based on opt-out is unacceptable
( ) SMTP headers should not be the subject of legislation
( ) Blacklists suck
( ) Whitelists suck
( ) We should be able to talk about Viagra without being censored
( ) Countermeasures should not involve wire fraud or credit card fraud
( ) Countermeasures should not involve sabotage of public networks
( ) Countermeasures must work if phased in gradually
( ) Sending email should be free
(x) Why should we have to trust you and your servers?
( ) Incompatiblity with open source or open source licenses
( ) Feel-good measures do nothing to solve the problem
( ) Temporary/one-time email addresses are cumbersome
( ) I don't want the government reading my email
( ) Killing them that way is not slow and painful enough

Sorry dude, but I don't think it would work.
Neil Smithline
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J Kimball
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