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Lousy E-mail Filters Complicating Outlook Worms
Mar writes "FRISK Software founder Fridrik Skulason has issued an open letter in which he blames other anti-virus companies for much of the Sobig.F network load problems: 'If mail filters send out one message for every copy of Sobig.F received, they are in effect doubling the amount of traffic. This makes them a part of the problem, not a part of the solution.'"
...traffic than you'd have if the worm got to its target and continued spreading.
After so many viri's that fake return to headers it's stupid to continue responding to them. No I didn't read the article...
The email bounce is nearly dead now. Between spam and viruses faking the from and reply-to headers, it's become almost a menace. I got nearly as many bounces as I did sobig messages.
This is completely stoppable at the ISP level. I received over 1,000 SoBig.F messages, not one of which had to go through!
It's Christmas everyday with BitTorrent.
Our Norton Exchange AV kicks out "we-saved-your-butt" emails to the admin, the original recip, and back at the "sender", who of course knows nothing about it since it was forged.
:) Serves AOL right...
I've just been creating more and more filters that send to trash with no notification to anyone.
Of course, you have to pay attention when you first turn some of the capabilities on, as Norton kindly preset you to block AOL mail
.sigs are for post^Hers.
Do most users exchange executable files? How about just blocking them if they're executable... How about getting an email client that isn't known for it's ability to spread received infected email without the user having to even open the email?
/been using pine since 1996...
Do not look into laser with remaining eye.
Not only are they doubling traffic, they can help spread the virus.. I've recieved bounced email containing the virus, since the the return address is randomized this in effect helps to spread the virus. Why include the attachment in a bounce message?
air and light and time and space
Why (some) anti-virus companies are to blame for the recent
e-mail flood
As everyone should now know, Sobig.F has generated a tremendous amount of e-mail traffic world-wide. However, part of the blame for this traffic should be placed on some of the anti-virus companies.
What I am referring to is the large number of incorrectly configured mail filters that respond by sending a "virus alert" to the "From:" address. As Sobig.F falsifies the "From:" address, these e-mails just clutter up the mailboxes of innocent, non-infected people. These messages cause unnecessary annoyance and worry, as they typically (and incorrectly) claim that people have sent out a virus.
When you get an e-mail, warning you of a Sobig.F infection, with a subject line similar to these:
* *** detected and quarantined a virus in a message you sent.
* Warning: E-mail viruses detected
* Virus Detected by ***
* This is an alert from ***
it usually means that someone, somewhere has made a bad decision on how to react to infected mail, either by selecting a substandard product or by configuring it incorrectly.
Worse yet, if mail filters send out one message for every copy of Sobig.F received, they are in effect doubling the amount of traffic. This makes them a part of the problem, not a part of the solution.
The problem is that some commercial mail filters have this behaviour set as the default. At least one filter gives only two options: Always send a "virus alert" to the "From" address of every infected e-mail received or "pass the message through to the recipient". Clearly neither of these options are acceptable.
I have only one word for this: Stupid!
Acceptable behaviour would be one of the following:
1. Have the mail filter properly distinguish between worms that falsify the "From:" address and ones that do not and only send a warning message when the "From:" address is likely to be genuine.
2. Do not send the alerts at all.
In fact, sending an alert automatically to the From: address for every virus or worm received by e-mail should not even be a selectable option.
With Sobig.F scheduled to die out today, Sept. 10th, the problem might go away for a while - until the next similar worm appears. And this is the scary part. Sobig.F didn't really infect that many machines world-wide, maybe only 200.000 or so. This is only a fraction of the number of machines infected by Msblaster (Lovsan). Now imagine a worm combining the distribution method of Msblaster with the mass-mailing feature of Sobig.F. The flood of traffic might practically render the Internet unusable.
Eventually, some virus author will create a virus like this, maybe this month, maybe in a few years, but it will happen. And when it does we do not need the anti-virus companies making a bad situation worse.
I hope the "guilty" anti-virus producers will be updating their products in the near future, but this is not going to happen unless their customers request it.
Fridrik Skulason ( frisk@f-prot.com )
Founder of FRISK Software International
"The price good men pay for indifference to public affairs is to be ruled by evil men." ~Plato (427-347 BC)
If the e-mail filter is smart enough to know it's Sobig.F, why isn't it smart enough to know the "from" is spoofed?!?!?
I set our filters to just delete anything with an executable attachment, but that didn't to crap for the stupid "Virus Detected" warnings.
One guy was sending us about 150 copies a day, and the others his PC sent out with our address as the "from" resulted in about 50-75 Virus warnings a day - from the first day it popped up until it expired. I had his IP address, and called and e-mailed his ISP (Birch.net) a dozen or more times, and they did squat. 150 x ~100k x # of people in his address book - not to mention the undeliverables and virus warnings - and they did nothing.
666-607: 6th floor apartment of the beast
The SoBig.(X) (all of 'em, been getting them for months, good thing Evolution doesn't care) are all around 100K a piece.
A "your message was filtered" is maybe 2-3K including all headers (more likely under 1k), so responding to messages with Virus' in them adds 1-3% not 100% to the traffic.
That being said, since most of the current generation of SoBig happily fake the "From" email address, a reply to the from address doesn't really help anyone either.
So in the worst case scenario, a 3K reply to a fake email address results in a bounce message, so at the most you've got 5% overhead, and theoretically for that 6K of email, you've saved a user from getting infected, which would generate 100K*1000's of data.
I'd say it's not too high a price to pay.
Please send all UCE to scally@devolution.com so I can f
One member of our software development team ended up receiving over 10,000messages/hour during our peak load, about equally split between virus messages, and bounce backs/mailer daemon messages. The latter weren't blocked by the standard anti-spam solution.
The messages generally contain no usefull information, and are deleted without reading.
Spam catchers should be combined with anti virus solutions, to ensure that authentic messages do generate some sort of response, either to the sender or receiving, informing them of the infection. The technologies would mesh well in this case.
paul reinheimer
last time
I work in Tech support for a telecommunications company and I get at least three calls per day regarding a message from Norton Antivirus. The message falsely states that they were a sender of the sobig.f virus. Of course, our users are completely up to date with their virus software and our e-mail servers catch the sobig virus. A big shame on you to Norton for having an e-mail enabled warning like that. It preys on the stupidity of end users.
Granted, if nobody talked about AIDS, the infection rate would probably skyrocket too. So is it better that there be a symptom of the virus such as increased network traffic. Or is it better to not inform external users and try to repair in house?
Maybe it offers a little job security too though.
One of my clients is an ISP - and they *want* the bounces to go out for the simple reason that it broadcasts to the world that "your mail is safe with us".
... For more information about our services come to --URL--"
So the bounce messages go something like "Our mail server detected a virus in an email you appear to have sent, and we protected our customer
I don't know if it's effective at all, but it sure doesn't cost much - the virus notification is essentially a mild form of SPAM which few people really get up in arms about.
Just to understand, there are market conditions behind those virus notices...
I have no problem with your religion until you decide it's reason to deprive others of the truth.
I just got a call from the Data Security guy in my office. I've had run-ins with him before, because their scans of my PC would occasionally find that I run Eudora for my personal email rather than routing it through the corporate virus portal known as Outlook Express. My bosses have been supportive -- as long as I get my work done, who the heck cares what I've got installed?
Now, I get 50-100 messages from "helpful" virus checkers telling me that I sent them a virus. Duh, of course I didn't. But what's worse is when they try to help my by sending the damned virus back to me! So my Eudora inbox fills up with viruses. No problem, I just delete them, right?
But we've got real-time virus scanning installed, and the admins take a dim view of tweaking it to skip certain directories. It finds that In.mbx contains a virus and kills the file. Poof, there goes my Eudora inbox. Frustrating, but it was full of junk anyway.
This morning, though, I get a call from the head Data Security honcho. Norton called mommy when it found the virus, and did it often enough for me to show up on the admin guy's radar again. Now, I'm going to have to quit using Eudora at work, just because brain-dead virus protection is sending me viruses! I'd fight it again, but I have to agree -- if I keep downloading viruses, I'm part of the problem.
Thanks for nothing, AV companies. All you're doing is keeping yourselves in business with false virus alerts. Or maybe that was the "2. ???" in between "1. Spread Viruses" and "3. Profit!"
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
I find this most interesting.
Until recently, no e-mail worms spoofed the email address. F-Prot obviously never had the functionality of replying to infected emails.
Until just recently, it was really good to reply to the sender alerting him about the fact that he sent out a virus/worm. Where was F-Prot back then??
The way I see it, it's been three steps.
Step 1: No email worms.
Step 2: Email worms that didn't spoof the sender (replying to sender is good).
Step 3: Email worms that spoof the sender (replying to sender is bad).
Seems to me that F-Prot is complaining that everyone hasn't reached step 3 yet (with spoofed sender addresses, infected emails shouldn't be replied to), even though we pretty much reached it just now. Before Sobig, even though there were worms that spoofed the sender, they were a minority. After Sobig, spoofing worms are a majority, which means that AV products need to change. This won't happen in a second like it did for F-Prot, because most AV vendors didn't skip step 2 like F-Prot did.
This coming from a company who 95% of computer users never heard, and who never even added the functionality of replying to emails even though it was really good until just recently, makes me believe his just looking for his two minutes of fame.
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We have Mail Marshall here at work. I got the following mail from the system yesterday...
:(
MailMarshal (an automated content monitoring gateway) has stopped the following email for the following reason:
It believes it may contain unacceptable language, or inappropriate material.
Message: B000038072.00000001.mml
From: xxx@xxx.com
To: xxx@xxx.com
Subject: Re: So Whuz Up?
Please remove any inappropriate language and send it again.
The blocked email will be automatically deleted after 5 days.
MailMarshal Rule: Inbound Messages : Block Unacceptable Language Script Offensive Language (Basic) Triggered
Expression: asshole Triggered 1 times weighting 5
Email security by MailMarshal from Marshal Software.
So the message tells both the ortiginal sender and I that it won't deliver the email because it contains the term "asshole". So it lets me know that by sending me an email telling me the exact same word that was supposed to be filtered? It seems like we've got a hypocrytical mail filter here
At no point should a response be generated for a virus. Maybe five years ago, when viruses tagged along with legitimate data, but nowadays, a virus generates it's own delivery system, and there's no point to a bounce.
Vintage computer games and RPG books available. Email me if you're interested.
The statement "If mail filters send out one message for every copy of Sobig.F received, they are in effect doubling the amount of traffic. This makes them a part of the problem, not a part of the solution" is also what I've been saying for months. This is a condemnation of challenge/response. Challenge/response is flawed conceptually in that it assumes the return address is correct. In an age of spam (which it supposedly addresses) and viruses it is absurd to believe the return address exists and sending email to the return address just multiplies the problem.
Challenge/response was never well thought out. It shifts the burden of spam filtering to the person that sends email to that user, and tends to mailbomb innocent users that happen to have their addresses forged by spam or viruses. All so someone can supposedly enjoy a spam-free existance with no thought to the hassle they are creating for others and the spam that they are creating by mailbombibf C/R challenges to forged addresses.
Hopefully with much better filters already available Challenge/response will just disappear. It's bad technology.
I received hundreds of bouncebacks from one organization. So, I did a whois and wrote to the contact listed:
My name is Geoff Fox and I am writing because I have received hundreds upon hundreds of message bounces from your **** mail server.
These messages are not originating with me. These are SoBig virus generated and are spoofing my address as the return.
I am asking nicely, but I need you to take action immediately. I am attaching a bounce message so you can see what I've received. From the headers it looks like they're actually coming from ***.com
Sincerely, Geoff Fox
I did get a response... but not what I had expected.
Geoff, Thanks for raising the issue of the SoBig virus infection.
From the information that you have provided, it does look like the infected machine is located at **** Architecs, Inc. of Harford, CT. Their contact information is provided below.
Have your IT technical staff contact the admistrative contact or the technical contact below. They may not realize that they have a SoBig infected machine and that it needs to be cleaned.
(whois stuff deleted)
It was signed by their Director of IT Security.
So, even at that level, he didn't realize he was doing something wrong... or that these bouncebacks came from him, not from the site that was infected. And, he felt it was my obligation to do something about it, not his!
Messages from known spamming autoresponders should be blocked by spam filters. A publicly available list of canned text appearing in messages from spamming autoresponders should be made available and placed into mail filters.
That should deal with the problem.
Lousy E-mail Filters Complicating Outlook Worms
SoBig.F is not an Outlook worm. It is a Windows worm. It does not require Outlook to run. It has it's own built in MTA and grabs email addresses from cached webpages and local text files as well as the Outlook/Express address book.
-Ab
Nothing fails quite like prayer.
I am currently looking into antivirus solutions for our company mailserver, and originally thought about disabling the bounce messages.
..
But unfortunately it seems that it could be illegal in Germany to intercept a message without notifying the sender. As far as I understand it, eMail seems to be subject to the same regulations as snail mail here, so dropping the message silently could constitute a legal hazard
Last year, my wife received a spate of "you sent this virus" messages. Worse, a number of her associates received "this person tried to send you a virus" message, referring to her.
I followed up with several of the administrators running the virus filters. In all cases, the administrators had quarantined the messages without headers so it was impossible to tell what machine really sent the message. I would have liked to know this information so as to have some hope of tracing the owner of the infected machine.
I understand why users are unaware of headers. Microsoft's products go out of their way to hide them. In Outlook Express, to get headers you have to find the relevant show headers pull-down and even then the headers appear in a too-small non-resizable window. You have to clip the contents and paste into a real window before the headers can be read/forwarded.
The "From:" field of email means no more than the snail-mail return address that you scribble on an envelope. The header, like the snail-mail postmark, tells the origin.
What is the excuse for vendors of email software (filtering or end-user) perpetrating unawareness of this basic property of email?
What is your definition of "recently"? Apparently it's about two years.
I administrate a mail server with around 550 accounts on it. We got slammed by Sobig.F and eventually had to block it using header_checks in Postfix.
This won't catch every virus-infected file attachment (like Word macro viruses), but the regex I put in place will block files with certain file extensions (e.g. pif, exe, etc.) What's nice is that the mail is rejected during the SMTP transaction and produces no residual mail traffic since the sending mail server is the worm's SMTP engine.
So, for anyone using Postfix 2 who would like to stop most e-mail worms, using header_checks to scan MIME headers is a very effective way to protect your customers/users.
The fact that the private keys are going to be stored on PCs owned by people who don't grok public/private key care one bit. Not to mention that a new worm should have no trouble lifting those keys off the box and spraying them around for a new forge attack.
Uh huh.
So you wanna read your personal email at the office. Fine if your company supports that.
But then you just absolutely positively gotta use only your favorite email client, not the one already installed, not a web portal. The email client now installed by you, presumably licensed to you, that is not owned or supported by IS. The one that makes IS's day that much tougher by throwing one more ingredient into the stew that is the company's desktop computer.
Now on top if it your personal email client reading your personal email is bringing in viruses to the company. Onto that corporate PC logged into the corporate network. And dammit those nasty folks in IS aren't willing to spend their time making exceptions to the virus scanning so your unique-in-the-company personal email client reading your personal, virus-infected email is exempted.
Cry me a river.
I don't read ACs: If a post isn't worth so much as a nom de plume to its author then I wont bother either.
I would imagine that most of the virus scanners for mail servers out there can be configured to not send out the notification to the forged From address. The virus scanner I am familiar with - RAV, has this capability. I had ours configured to send out the notification until Klez and other viruses made it a worthless endeavour. Unless of course you are an ISP that has no qualms about using the opportunity to advertise.
It would be nice if GeCAD would rewrite their software to stop the notice from being sent when the virus is Klez, Sobig, etc. But since GeCAD got bought out by Microsoft who will be discontinuing their product line, I know that will never happen. Hopefully someone else like Sophos will.
No, the math's still off. If x is the so big rate, and y is the exponential propogation rate, and A is the AV copmany's market share (between 0 and 1), the rate of propogation of Sobig is x^y. The rate of propogation of bounces is A(x^y). So the propogation rate of sobig + bounces is (1+A)(x^y), not (x+1)^y. Actually, if I amended your math, it would be worse (your formula assumes that a bounce can be branched). There, it would be (x+Ax)^y. And that would be a phenomenal impact. The way you write the formula (x+1)^y, it assumes that only one bounce were ever sent. If that were the case, no one would worry. But it's not. And if you take the derivative of my amended version of your formula, which is the incremental impact per message sent, it increases exponentially too. Think about that. I can do the calculus too if you like. Either way, it's bad. At best the impact is a constant fraction of the sobig rate. At worst, they work together geometrically.
What does one do if they think they have a virus? If they are in a corporate environment, they ping the help desk (and that would be ONCE per person, regardless of the number of emails they get).
Yeah, and in a large environment of thousands of people, that's *exactly* what the help desk needs. Trust me, I know some of these people, and it's driving them nuts.
If they are a home user, they make sure they have updated virus software. If they are clueless, then they will take it somewhere and get anti-virus software installed.
And if they were already up-to-date, then they just paid money for nothing. And once they get up-to-date and know they're OK, and they keep getting messages, they learn to ignore them. So when another message comes out that they're not prepared for, they think they are.
-Looking for a job as a materials chemist or multivariat
The real answer is that virus definition files should have a flag that is set for viruses that always use forged addresses that tells the antivirus never to send an email in reply to that virus.
"Reality is just a convenient measure of complexity" -Alvy Ray Smith