email

Law, PR Firms Being Targeted by Hackers says FBI

According to the Washington Post, “Hackers are increasingly targeting law firms and public relations companies with a sophisticated e-mail scheme that breaks into their computer networks to steal sensitive data, often linked to large corporate clients doing business overseas.”

Needless to say, I’ve informed all of my clients who may be affected.

The attacks turn out to be classic “spear phishing” attacks and they can be very convincing. (Recall that a couple of years ago, dentists were targeted.) Here’s what the FBI has to say about the current round of attacks:

[The FBI says hackers are using] spear phishing e-mails with malicious payloads to exploit U.S. law firms and public relations firms. During the course of ongoing investigations, the FBI identified noticeable increases in computer exploitation attempts against these entities. The specific intrusion vector used against the firms is a spear phishing or targeted socially engineered e-mail designed to compromise a network by bypassing technological network defenses and exploiting the person at the keyboard. Hackers exploit the ability of end users to launch the malicious payloads from within the network by attaching a file to the message or including a link to the domain housing the file and enticing users to click the attachment or link. Network defense against these attacks is difficult as the subject lines are spoofed, or crafted, in such a way to uniquely engage recipients with content appropriate to their specific business interests. In addition to appearing to originate from a trusted source based on the relevance of the subject line, the attachment name and message body are also crafted to associate with the same specific business interests.

I wasn’t able to find the text of the latest emails floating around in this spear phishing campaign, but the above description should give you a clue.

Real Spam Statistics

Depending on whose reports you view, spam accounts for from 85 to 95 percent of all emails sent. This may hold true over the Internet at large, but as with any other statistical data, there are local and regional variations. My own inbox is an exception to the general rule; I get far more legitimate emails than spam.

The company I work for provides spam filtering for several SMBs, so I have to hand real data that I can evaluate. Based on last week’s numbers, we processed nearly 100,000 messages in our filters. Of those messages, nearly 70,000–70%–were spam; nearly 30,000–30%–were accepted as legitimate. Our data has its own wild variations: one set is very low with only 18% spam; another set reaches a high of 92% spam.

I’m not a statistician, but it’s easy for me to see how big a problem spam has become. I’m not ready to say email is dead as a business communication medium, but it certainly needs an overhaul.

Beware of E-Mail Scam Targeting Microsoft Customers

The latest e-mail scam targeting Microsoft customers delivers the Backdoor:Win32/Haxdoor trojan as an attachment. The email looks like this:

Dear Microsoft Customer,

Please notice that Microsoft company has recently issued a Security Update for OS Microsoft Windows. The update applies to the following OS versions: Microsoft Windows 98, Microsoft Windows 2000, Microsoft Windows Millenium, Microsoft Windows XP, Microsoft Windows Vista.

Please notice, that present update applies to high-priority updates category. In order to help protect your computer against security threats and performance problems, we strongly recommend you to install this update.

Since public distribution of this Update through the official website http://www.microsoft.com would have result in efficient creation of a malicious software, we made a decision to issue an experimental private version of an update for all Microsoft Windows OS users.

As your computer is set to receive notifications when new updates are available, you have received this notice.

In order to start the update, please follow the step-by-step instruction:
1. Run the file, that you have received along with this message.
2. Carefully follow all the instructions you see on the screen.

If nothing changes after you have run the file, probably in the settings of your OS you have an indication to run all the updates at a background routine. In that case, at this point the upgrade of your OS will be finished.

We apologize for any inconvenience this back order may be causing you.

Thank you,

Steve Lipner
Director of Security Assurance
Microsoft Corp.

Anyone reading this can spot the obvious grammar and punctuation mistakes, the first things that should alert them that this is a scam. But, as we know, users blindly click on anything and everything, especially links in official-looking messages.

Please advise your users to immediately delete this message if they receive it, and continue to advise them to NEVER click a link or open an email that they are not sure about. It’s better to err on the side of caution.

By the way, Consumer Reports has an Online Security Guide posted on their website. It’s well worth looking at and certainly good for your non-savvy users as it’s written for, well, consumers.

The Best Way to Avoid Spam

In the 1986 hit movie, The Karate Kid - Part II, the kid’s instructor, Mr. Miyagi, uttered this famous line: “Best way to avoid punch, no be there!” Good advice, indeed; it’s one of those universal pieces of truth that’s so obvious, it’s overlooked. The beauty of it is that it can be applied to anything. In this case, I’ll apply it to spam email, the electronic equivalent of a punch: “Best way to avoid spam, no have email address!”

That’s not exactly practical; we all have an email address. Some of us have several of them (at last count, I have at least nine addresses and I’m sure I’ve missed a couple somewhere). In my final installment of the “How to Secure Your Computer” series, “If Spam has You Irate, Obfuscate!” I gave examples of how you can make your email address unreadable by web bots. Well, that can be a bit of work, forcing you to cut and paste, and make other efforts that can quickly become tedious. There’s an easier way.

Enter Mailinator, the completely anonymous email address that you create on-the-fly when you need to enter an email address but don’t want to use your real one. From their site:

How do I create an account at Mailinator? It’s simple, you just send email to it. Temporary accounts are created when email arrives for them. First, you give out the mailinator email address you created, and then you check it. It’s that simple.

Do I have to sign up? No sign-up, you don’t even have to tell Mailinator you’re coming.

It’s a valid, working email address that you can check just by visiting the site. Of course, anyone can check it just by entering the address in the “Check your inbox” box. Not the best of situations, so they fixed it by providing alternate inbox names . In a nutshell, you use the alternate inbox name for your email address when you post it publicly. Anyone who enters the alternate inbox name will simply get a “no messages” message. Pretty slick.

The beauty of Mailinator is that it provides a valid email address; you can download stuff from and subscribe to those sites that require clicking links in confirmation emails without having to worry about exposing yourself to spam. Use the alternate inbox name or even a different email address every time you need one.

Best way to avoid spam, no have email address — or at least use one you can throw away at will. Either way, you avoid the punch and the security risk.

Sure-fire Spam Zombie Killer

The other day, I got a call from one of my clients who said that their email was bouncing back from people they had always been able to send to. I investigated and found that the error message was to the effect of <hostname.domain #5.5.0 smtp;550 Blocked;Spam/Zombie address listed at spamhaus.org sbl-xbl>.

Well, that was odd, because the client is running a bona fide Exchange server and a check of the server revealed nothing wrong that I could see. Thinking that maybe an employee was infected with a mass-mailer trojan, I blocked all traffic on smtp port 25 from all addresses on the network except the Exchange server.

Running the netstat -an command on my client’s PC revealed 88 connections, all trying to send mail out on port 25, which the firewall was now blocking.

Certainly, you don’t want to get infected by a mass-mailer trojan, but blocking outbound traffic on port 25 from your network is a sure-fire spam zombie killer and will prevent your IP address from getting blacklisted if someone does get infected.Of course, you’ll want to clean up that infection as quickly as possible.

Turn Off Message Preview in Your Email Client

Some of these tips may very well be “everybody knows” types of things, but I find that these are often the things that get overlooked. That’s why I’m publishing them as computer security maxims. Take a look at the recent furor surrounding the cold boot attack against disk encryption . That was an “everbody knows,” too.

I get questions all the over at Ask the Geek about using a mail client’s message preview feature. Opinions vary, of course, but for this geek, it’s a bad idea. In order to preview a message, it has to be opened or rendered by the HTML engine. Think about how a PC can be infected by a malicious web site and you’ll immediately understand the danger: The same malicious programs can exist in scripts in HTML messages. It’s a serious security risk.

Security Maxim #6: Always disable any message preview or auto-open features in your e-mail client. View messages as text-only until you know they are safe.