Security Watch

Keeping Track of patches and hacks in the IT security world.

New Firewall Testing Mechanism: Baiting on Chatrooms

A Sunbelt researcher, who shall go unnamed for what will soon be obvious reasons, has come up with a novel method of testing firewalls—novel, and completely unsanctioned by his employer, Sunbelt President Alex Eckelberry hastened to add when he told me about it earlier this week.

The method: give yourself a handle like "TheHebrewHacker" and post pro-American, pro-Israeli sentiments on Arabic chatrooms. Then, sit back and watch the real-world attacks start peppering your goods.

To wit: "Finish the job in Iraq! Red White and Blue Forever!" and "Israel will survive" is what he posted on "Palestine Chatroom" of "WeArab."

His rationale: "Sure, you can use leak test programs to determine whether or not your firewall prompts you if your computer makes an outbound connection, but what about incoming connections? Truly testing a firewall's strengths and weaknesses requires testing incoming and outgoing connections. What better way to test a firewall then actually putting it through real-world scenarios?"

There are several programs out there to test various incoming connection attacks. The problem with some of those programs, however, is that they may not necessarily be updated to include new vulnerabilities or exploits, he told me. Prior to running this test, the researcher had in fact used several Linux-based penetration-testing programs, including Nessus, NMAP and Metasploit to see if SPF (Sunbelt Personal Firewall) would catch the breaches.

He suggested what he said is a very good Linux live CD—meaning you don't have to install it to a hard drive—that contains various penetration-testing utilities. It's called BackTrack 2, and it can be downloaded here.

This is what he did: First, he installed MIRC, an Internet relay chat program. He connected to and entered a few Arabic speaking chat rooms. He knew, he said, that the screen name chosen, "thehebrewhacker," was "sure to cause a stir in the 'pro Arab' channels."

After leaving the inflammatory messages for the users in the room, he sat back and waited to see what sorts of attacks would come his way.

Soon after posting, he started receiving incoming connections. He let the computer sit overnight, still logged in to the chat rooms. Upon coming back to work the next day, he checked out the logs from SPF.

The computer in question was firewalled only through SPF, not through a hardware firewall. He saw a variety of things come in, including an Internet-Explorer-based iFrame attack that, depending on the particular exploit, could cause a denial of service on the machine, especially if it was not fully patched or protected by a firewall.

Primarily, the logs showed ICMP requests: port scans on the machine to find any potential holes. The attackers did some OS fingerprinting and port scanning to determine what operating system the machine was running and to find open ports.

One of the many important features that SPF has is the ability to run SNORT rules—rules that allow SPF to perform real-time packet analysis. "The benefit to this is that as new exploits are released, SPF can be automatically updated to detect them," the researcher told me.

And, in fact, what really caught his attention were the DoS attacks, typically caused by bot networks. There was nothing that he hadn't seen at other times, but the sheer speed in which the attacks occurred was attention grabbing, he said.

The end result: He got "kicked and banned" from the chatroom.

"Oh well," he said. "The firewall held up wonderfully."