K-Squared Ramblings

Ahead of their time

Remember when the web was young, and email was just gaining popularity in the mainstream, and there was a slew of virus hoaxes like the Good Times Virus, or It Takes Guts to Say Jesus, or Elf Bowling?

Remember painstakingly explaining to people that no, your computer couldn’t get a virus just by reading an email, you had to click on an attachment? That images were safe to open? Remember when the worst people had to worry about from web pages was unwanted cookies? Getting a virus just from looking at a web page? Preposterous! And a virus that ran up your credit card? Ridiculous!

It’s sad to think that all those “ridiculous” things are now possible—in fact, they’re commonplace. Look back at that link up there. It’s Snopes’ page on computer virus warnings. Way back when, they were all bogus. These days, most of them are real.

So what’s next? Well, they keep talking about Internet-aware appliances, so a future virus probably could “recalibrate your refrigerator’s coolness setting so all your ice cream goes melty.”

Web worm in MySpace

Worms of the future: someone on MySpace *ptui!* came up with an actual JavaScript worm using cross-site scripting exploits and XMLHTTPRequest. In 24 hours, the worm had forced 1 million users to add him to their friends lists.

Personally, MySpace bugs the heck out of me because it seems to have a culture that encourages embedding images from other sites. 18% of hits to hyperborea.org from other websites are from myspace. Admittedly that’s inflated by the fact that attempts to embed images from my Flash site redirect to the actual articles, so it’s probably more like 10%, but it’s still insane. Earlier this week I started blocking hits from MySpace to images posted on this blog, and I plan to do the same with the Flash images over the weekend. You like my photos? Great, link to my actual site! You like the scan I have of some movie logo? Great, copy it and upload it to your own site!

(via Slashdot)

Viruses: They’re not just annoyances anymore

If you’ve been paying attention to computer security, you already know that spam, viruses, and organized crime have been in bed together for at least a year. The recently-discovered theft of 40 million credit card numbers [edit: originally linked to Yahoo News] illustrates this point clearly:

CardSystems was hit by a virus-like computer script that captured customer data for the purpose of fraud, [MasterCard spokeswoman] Gamsin said. She said she did not know how the script got into the system. The FBI was investigating. (emphasis added)

Given the current porous state of many networks and operating systems, and the general public’s attitude that catching a computer virus is as inevitable as catching a cold, I’d guess it got into the system the same way most spyware does. An email attachment squeaked by the filters. Someone installed a tool that claimed it would make their web access faster. Someone got a well-designed phish, followed the link, and got infected by a backdoor because their browser was behind on security patches. Someone brought a laptop home, plugged it into their insecure home network, and brought back a virus.

Sadly, I expect we’ll be seeing a lot more of this.

Update June 20: Netcraft is reporting that it was indeed lax computer security that did them in:

MasterCard International said it “worked with CardSystems to remediate the security vulnerabilities in the processor’s systems. These vulnerabilities allowed an unauthorized individual to infiltrate their network and access the cardholder data.” Officials at affected institutions were not specifying the vulnerability and exploit used to breach CardSystems’ security. (emphasis added)

Netcraft seems to think it was likely their website, which runs on Windows 2000 and IIS 5, and they go on to promote their own security consulting services. So it’s not entirely an unbiased look at the incident.

Sometimes viruses can’t read either

Over the last few days, one of the viruses going around (probably a Mytob variant) has been trying to send its “Your account is being suspended! Open this file now!” come-ons. It forges the return address as support@example.net, admin@example.net, etc. We block any incoming mail using these addresses before it even gets to our virus scanner.

Now here’s the weird part. We’re also getting bounces sent to another domain we manage, let’s say another-example.com. Both sets are coming from someserver.another-example.com.br!

I think that the virus is finding itself on another-example.com.br and not recognizing the country-specific domain name, misreading it as just another-example.com. It then looks up the mail server, finds our domain, and targets both.
Read the rest of this entry »

Viral Genesis

Received 9 messages to a set of related spamtraps. All identical, claiming to be an E-Gold payment with an attached zip file containing a scan of the check. Our server found that zip file suspicious and defanged it. The funny thing? While the From: lines all varied, they all claimed to be from Peter Gabriel.

Outlook Viruses Trash Non-Outlook Mailboxes

Mozilla developer Ben Goodger writes about losing his inbox to the latest virus… despite not using any vulnerable software. Apparently he’s been getting over 10,000 virus-laced messages every day, and with the four-day weekend they built up to the point that Thunderbird wasn’t able to handle the influx. (Imagine having to filter out 770 megabytes of junk every day, and having that build up over several days.)

Sure, the the pre-release Thunderbird still has problems dealing with very large folders, but 770 MB/day? Even Gmail only gives you 1 GB of total storage. I can’t think of any reasonable expectation that any mail client should have to deal with that at today’s level of data richness. Maybe in the future when we’re sending full-motion video on a regular basis, but not when most email is text with maybe some formatting and a couple of small images.

It’s just staggering that, even though the main email worms depend on Microsoft Outlook, Outlook Express, and Internet Explorer to spread themselves and infect new hosts, they can still damage systems that don’t use those programs!

Internet Explorer: Unsafe at any speed

Netcraft reports on a series of malicious banner ads using a vulnerability in Internet Explorer 6 to spread the Bofra virus. Clicking on the banners sends you to a website that uses the recently-discovered IFRAME vulnerability to infect your computer. Of note are the facts that there is no patch for this yet, and XP SP2 is affected (whoops, I misread that part).

The Register found the ads on their own website and identified the source as ad server Falk AG. They have pulled Falk AG’s ads from their rotation and apologized to their readers. Netcraft adds that Falk AG’s clients include high-profile sites such as A&E, NBC, and Sony. The ad company has issued a statement, but the page currently consists of the line “Server Engine: Application error.”

Update 3pm: The statement from Falk [archive.org] is readable now. Apparently someone broke into one of their network load balancers and reconfigured it to redirect ads to the malicious site. Once they discovered it, they shut down the affected system and started checking the rest. The malicious ads ran for a total of about 6 hours on Saturday.

Update Tuesday: the Internet Storm Center has posted a write-up of the attack response.

Of course, there are several ways to protect yourself from this type of attack.

Another bogus warning

Here’s another one. First the notice they sent me:

Subject: VIRUS (Worm.SomeFool.P) IN MAIL FROM YOU

VIRUS ALERT

Our content checker found
    virus: Worm.SomeFool.P
in your email to the following recipient:
-> ADDRESS REMOVED

Please check your system for viruses,
or ask your system administrator to do so.

Delivery of the email was stopped!

And now my response:

Subject: BOGUS ALERT (sent to wrong address) IN MAIL FROM YOU

BOGUS WARNING ALERT

My BS checker found
    bogus warning: notice sent to known-forged sender
in your email to the following recipient:
-> MY ADDRESS

Please check your virus scanner for better notification options,
or ask your system administrator to do so.

All modern email-based viruses forge the sender address. Additionally, since your virus scanner was able to identify the specific virus, it can determine on its own that this virus always uses a forged address.

By notifying the supposed sender of a message when you know that sender is forged, you are knowingly sending virus warnings to people who are, in all likelihood, not using an infected computer. Messages like these are just noise, and the more of them that are sent, the less attention people will pay to *real* warnings. Additionally, it also runs the risk of causing unnecessary concern among the less tech-savvy (and extra calls to tech support about the nonexistant virus they fear they have).

(Feel free to re-use my response. I partially quoted myself anyway.)

I’m contemplating building a “hall of shame” and actually posting the sources of some of these. Any thoughts?

Out in the open

Just what we need. Netcraft reports a worm that installs a network sniffer.

What’s that? It’s a program that listens in on traffic going across your network, looking for things like, oh, login names and passwords, credit card numbers, etc. They’re the reason online commerce requires SSL encryption.

Sniffers work because of the way ethernet is designed. Basically your local network is like holding a conversation in a crowded room. You focus on the people you’re talking with, and you tune out other people as best as you can. (In this case there’s also someone at the door who can relay your words to someone in another room, and relay back their responses.) To hold a private conversation you have to go somewhere else or talk in code. A traffic sniffer just doesn’t tune anyone out, so it picks up on everything in your local network.

So now, no matter how well you guard your own computer, if some moron on your network manages to get infected by Worm.SDBot (which thankfully hasn’t been spotted “in the wild” yet), you could still be handing out your email login/password when you log onto Yahoo/Hotmail/Outlook/etc.

You just might want to use that “secure login” option. Assuming, of course, that you have one.

Go away or I shall taunt you a second time!

Now this is interesting: the Amus worm will verbally taunt the user using Windows XP’s speech-generating features. F-Secure has posted a .wav, and McAfee’s writeup has an MP3.

Oddly, Symantec’s entry says nothing about the speech. Maybe they don’t have speakers on their test boxes.

Check the wording!

Oh, this is good!

You may have heard a few days ago that the latest MyDoom variant includes a request for work in the antivirus industry.

Well, the comic strip User Friendly has come up with the perfect solution!

Giving virus writers honest work

By way of Justin Mason and the SpamAssassin mailing list comes this post about writing add-ons for Outlook.

Seth Goodman writes of Outlook’s contact list:

This feature was apparently added for the convenience of virus writers, who it appears were one of the key groups that set the design requirements for this product

Ronald F. Guilmette replies:

So if I want source code for a software tool that can extract addresses from a personal Outlook address book, I guess that I should just go out and hire a virus writer! Hummm. I would have no problem with that. At least this would give them some honest work for a change… keeping them off the streets and out of trouble for a short while.

So now, where does one post a ‘HELP WANTED’ ad for a virus writer?

Outbreak

A new virus has been running around today, hiding in files like price08.zip, new_price.zip, etc. We got a call from a customer asking what this [Defanged] notice was all about, at which point I looked at the logs and found a lot more instances. By the time our virus definitions were updated to recognize it (currently ClamAV identifies it as Trojan.JS.RunMe. Edit: McAfee and F-Secure identify it as a new Bagle variant - either W32/Bagle.aq@MM or Bagle.al), about 45 copies had made it through virus scanning but were caught by MIMEDefang, which found the attachment suspicious anyway.

The moral of this part of the story: relying on virus signatures isn’t enough. By the time Norton, McAfee, F-Secure, ClamAV, etc. has identified a signature and your scanner has grabbed the updated files, it’s too late. Some copies have gotten through.

The next part is kind of interesting: This virus is clearly harvesting addresses from the web or from browser caches, because we’re seeing hits to our spamtraps. The really weird part: half of those hits claim to be from our other spamtraps!

But it is kind of odd for a new outbreak to hit the day I read this article: Security expert Q&A: The virus writers are winning.

Wolf Cry

More “You sent a virus!” garbage going around. It’s gotten to the point where I don’t even look at most delivery failure notices, which means I could easily miss errors about mail I really did send.

I got ticked off enough this time that I wrote back to the return address on the warning, matching the tone and structure of their message as closely as possible:

An invalid virus notice was found in an Email message you sent. Your Email scanner recognized a virus as W32/MyDoom-O but did not take into account the fact that this virus always uses a fake sender address.

Please update your virus scanner or contact your IT support personnel as soon as possible as you are sending bogus virus warnings to third parties whose systems are not infected with the virus. This runs the risk of causing unnecessary concern among the less tech-savvy (and extra calls to tech support about the nonexistant virus they fear they have). I would recommend reading up on the phrase “crying wolf” as well.

Total Waste of Bandwidth

I regularly get bogus bounces from clueless virus scanners that don’t realize the sending address is fake 99% of the time, but this takes the cake:

Sometime last night I received three copies of the same notice from some system in Brazil. They had written their virus warning in Microsoft Word, saved it as HTML without cleaning up all the extra junk, and made it the only part of the message… in Base64 encoding!

If you’re going to send any kind of diagnostic notice by email, you want it to be as simple and widely readable as possible. That means plain text (not HTML or Base64, and certainly not both!) It also means if you do want to use HTML, at least clean it up and include a plain-text alternative. For all you know it’s going to be read by some admin logging into a GUIless server through SSH over a modem connection on a hotel phone line!