Containing Conficker

March 30, 2009 by Eliot 50 Comments

conficker

With all the noise about Conficker turning your computer into liquid hot magma on April 1st, there’s actually some positive news. Researchers from the HoneyNet Project have been following the worm since infections started in late 2008. They recently discovered an easy way to identify infected systems remotely. Conficker attempts to patch the MS08-067 vulnerability during infection. A flaw in the patch causes the machine to respond differently than both an unpatched system and an officially patched system. Using this knowledge, the team developed a proof of concept network scanner in python to find infected machines. You can find it in [Rich Mogull]’s initial post. [Dan Kaminisky] has packaged it as an EXE and has instructions for how to build the SVN version of Nmap, which includes the new signature. Other network scanner vendors are adding the code as well.

In conjunction with this detection code, the team has also released the whitepaper Know Your Enemy: Containing Conficker. It discusses ways to detect, contain, and remove Conficker. They’ve combined this with a tool release that covers Conficker’s dynamic domain generation among other things.

Sniffing Keystrokes Via Laser, Power Lines

March 20, 2009 by Eliot 26 Comments

keystroke

Researchers from Inverse Path showed a couple interesting techniques for sniffing keystrokes at CanSecWest. For their first experiments they used a laser pointed at the shiny back of a laptop. The keystrokes would cause the laptop to vibrate which they could detect just like they would with any laser listening device. They’ve done it successfully from anywhere between 50 to 100 feet away. They used techniques similar to those in speech recognition to determine what sentences were being typed.

In a different attack, they sniffed characters from a PS/2 keyboard by monitoring the ground line in an outlet 50 feet away. They haven’t yet been able to collect more than just single strokes, but expect to get full words and sentences soon. This leakage via power line is discussed in the 1972 Tempest document we posted about earlier. The team said it wasn’t possible with USB or laptop keyboards.

[Thanks Jeramy]

Sslstrip, Hijacking SSL In Network

February 23, 2009 by Eliot 21 Comments

Last week at Black Hat DC, [Moxie Marlinspike] presented a novel way to hijack SSL. You can read about it in this Forbes article, but we highly recommend you watch the video. sslstrip can rewrite all https links as http, but it goes far beyond that. Using unicode characters that look similar to / and ? it can construct URLs with a valid certificate and then redirect the user to the original site after stealing their credentials. The attack can be very difficult for even above average users to notice. This attack requires access to the client’s network, but [Moxie] successfully ran it on a Tor exit node.

Curiosity Killed The Twit, Twitter Clickjacking

February 12, 2009 by Eliot 24 Comments

Twitter was flooded this morning with users posting “Don’t Click: http://tinyurl.com/amgzs6”. TinyURL has since terminated the URL. The original page doesn’t seem to be live either. It displayed a button that said “Don’t Click”. If the user happened to be logged into Twitter, it would automatically update their status. The instigator partially describes the method on his blog (translated). The page would load the user’s Twitter page in an invisible iframe. The status would be pasted in and the “Don’t Click” button is placed on top of the update button. You can find the code snippets here and the original author credits this post for the inspiration. Twitter has since added a JavaScript fragment to each page to break out of iframes.

if (window.top !== window.self) { window.top.location.href = window.self.location.href; }

BackTrack 4 Beta Released

February 10, 2009 by Eliot 101 Comments

backtrack

The Remote Exploit Development Team has just announced BackTrack 4 Beta. BackTrack is a Linux based LiveCD intended for security testing and we’ve been watching the project since the very early days. They say this new beta is both stable and usable. They’ve moved towards behaving like an actual distribution: it’s based on Debian core, they use Ubuntu software, and they’re running their own BackTrack repositories for future updates. There are a lot of new features, but the one we’re most interested in is the built in Pico card support. You can use the FPGAs to generate rainbow tables and do lookups for things like WPA, GSM, and Bluetooth cracking. BackTrack ISO and VMWare images are available here.

TEMPEST: A Signal Problem

January 25, 2009 by Eliot 12 Comments

TEMPEST is the covername used by the NSA and other agencies to talk about emissions from computing machinery that can divulge what the equipment is processing. We’ve covered a few projects in the past that specifically intercept EM radiation. TEMPEST for Eliza can transmit via AM using a CRT monitor, and just last Fall a group showed how to monitor USB keyboards remotely. Through the Freedom of Information Act, an interesting article from 1972 has been released. TEMPEST: A Signal Problem (PDF link dead, try Internet Archive version) covers the early history of how this phenomenon was discovered. Uncovered by Bell Labs in WWII, it affected a piece of encryption gear they were supplying to the military. The plaintext could be read over that air and also by monitoring spikes on the powerlines. Their new, heavily shielded and line filtered version of the device was rejected by the military who simply told commanders to monitor a 100 feet around their post to prevent eavesdropping. It’s an interesting read and also covers acoustic monitoring. This is just the US history of TEMPEST though, but from the anecdotes it sounds like their enemies were not just keeping pace but were also better informed.

[via Schneier]

Manual Protocol Analysis

January 24, 2009 by Eliot 2 Comments

packetfu

As a followup to last week’s post on automated protocol analysis, [Tod Beardsley] has written up how to start analyzing a protocol manually. He walks through several examples to show how to pull out the interesting bits in binary protocols. His first step was sending 10 identical select statements and capturing the outbound packets. He used the Ruby library PacketFu to help with the identification. It compared the ten packets and highlighted one byte that was incrementing by four with each packet, probably a counter. Looking at the response indicated a few other bytes that were also incrementing at the same rate, but at different values. Running the same query on two different days turned up what could be a timestamp. Using two different queries helped identify which byte was responsible for the statement length. While you may not find yourself buried in HEX on a daily basis, the post provides good coverage of how to think critically about it.