Major botnet building and the massive jump in spam



For a few months now (since the demise of bluefrog actually) I’ve noticed that the level of junk mail has gone up on my own mail server. Yes, I use spamassassin to filter and tag, but the volume of stuff that’s tagged has gone up (as well as the volume that slips through.) I’ve had to flush out the bayes filter more than I would like after some massive bayes poisoning attempts (those messages with lots of random words or text.) I’ve also been following news on the topic and thought I’d detail some of it here for those that haven’t been paying attention.


First up, most all spam doesn’t really come from the address listed as “FROM” I am constantly amazed at how many people are trying to “block sender” in Outlook Express and thinking that will make a difference. It won’t, it will either blacklist innocent bystanders or you will have a long and useless list of “disposable” addresses that spammers sent from. Now, I say, disposable addresses, that isn’t to imply that the spammer had to do ANYTHING to register or setup an address, it just means that say if a spammer targets this domain as the “FROM” source they will make up thousands of randomized addresses from averyjparker.com – they can send it without even using averyjparker.com’s server to relay the messages. In fact, they likely come from a botnet of thousands of home pcs around the world. But, in the scenario I describe above, averyjparker.com would receive the bounces or backscatter of the spam attack. That is, delivery failures, complaints, people asking to unsubscribe, etc. All to a third party uninvolved in the spamming. Not a bad racket for the spammer if you think about it.

So, what’s the goal with spam? Probably money. Let’s face it, I see a lot of stock spam – I’d be willing to bet the sender bought up quite a bit before clicking send and will sell quite a bit within 2 or so days after the stock spam. Just think of the effect if you were to buy 1000 shares of something at $1 and then were to go on national media talking up the prospects of this company, within a day, let’s say the stock has gone up to $2 and you sell, with a nice profit. The “pump and dump” stock spam works the same way.

But there’s product spam too and apparently that sells enough to be worthwhile (maybe if it’s JUST advertising revenue in clicks on ads.) Of course there’s also the spam filter poisoning runs which are meant to just make junk filters less effective and let more of the junk through. On the other end of the equation are the botnets. Home pcs, maybe yours or your neighbors pc. You don’t notice anything wrong, but while it’s online it’s part of a larger network and takes part in all sorts of activities you wouldn’t like. It’s possibly sending viagra spam, or maybe it’s hosting a porn site with illegal content, or maybe pirated software? It could be taking part in other activities as well and you possibly wouldn’t notice much of anything. The viruses of the late 90’s were obvious and brash and got big headlines. They spread big and quickly making an OBVIOUS impact on computers performance.

The viruses of today are much more subtle. Not too long ago I had someone say, “well there haven’t been any viruses lately”. I couldn’t help but look at them as though they stepped out of another time… Well, there haven’t been any in the major NEWS lately, but last I knew there were around 100 or so a month released, give or take. One antivirus scanner I have updates itself as many as 10-12 times per day, and it’s not updating because it’s fun, it’s updating to keep up with new threats as they emerge. They are more subtle these days though. I saw a warning this morning…. of a new trick in the bad guys bag, actually it’s a variation on a theme. It runs like this, unsuspecting person get’s an email about an order they have supposedly placed online. If they want to see details click the following link…. (trojan quietly installs.) Or…. they get an email with a “pdf” attachment that has details of the transaction they’ve just supposedly completed. Again, the pdf has a trojan. But, you might say wouldn’t people avoid clicking on that if they hadn’t purchased something? These days don’t you think if someone saw an unauthorized purchase confirmation they WOULD click to investigate? Yep, they’re tricky huh?

As for subtle. I’ve seen systems that were infested with trojan horses of various kinds and gave no reall noticable indication. I don’t know whether to give credit to Microsoft for a more stable Windows XP, or to virus writers for more stable virus/backdoor applications. Another of the things that always gets me is how clueless some people are about how a virus can operate. When I tell someone that their system has had a trojan and among other things all their online logins (read credit card numbers/logins/etc.) could have been logged, it could have been sending out tons of spam (thousands of messages an hour), or hosting illegal content, etc… many times I’m met with “well, I haven’t noticed more mail going out than what I’ve sent.” “See, you can check my “sent items”….” Uhm…. (the next explanation is the hard part.) most viruses don’t use outlook express to send out junk mail, it has it’s own engine for sending out messages if that’s it’s role. The other one that get’s me is “no one has logged on to my machine because I haven’t seen the pointer moving/ programs opening.” Ummm…. it’s possible to be logged in remotely without things turning up on the local display.

Anyway, as I’ve said before we’re in a war of sorts between the security industry and the botnet builders/spammers/etc. Right now, I don’t think we’re winning. Here’s why…. significant rise in botnet activity behind surge in spam, massive surge in spam hits the internet, Why so little attention to botnets? This last article asks why there is so little coverage of the problem of botnets among non-experts and I think the answer is this…. it’s too abstract a concept for most computer users to relate to. To most users there is nothing wrong with their pc unless it’s sending an error message or acting slower or less stable than they’re used to. In fact, there’s a perception threshhold there as well. (If it normally takes 3 seconds to open a browser window, will the user notice a 3.2 second open of a browser window – likely not.) Here’s more on the reports of increase numbers of infected systems, more on the link to spam.

I remember one of my posts on the old version of this site talked about the convergance of viruses and spam and at the time I was one of the ONLY people mentioning and highlighting this link. These days the awareness is higher, but it is STILL NOT common, conventional wisdom amongst the general population. I think what we need is a very large urge to personal responsibility and a push to encourage individuals to ensure that 1) they are running current antivirus on their pcs and keep it updated 2) help 2 or three other computer users make sure that they as well have current antivirus and can keep it updated.

We will NOT win this struggle without millions of people taking responsibility for computers under their control. I don’t care if you install Norton, McAfee, or what (AVG is free for home/personal use) (http://free.grisoft.com) I recommend AVG quite a bit because it IS free for home users, there are a few other free for home/personal use antivirus packages out there, but please help in this struggle against the botnets and spammers.

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