Archive for the ‘Cryptography’ Category

Breaking Wi-Fi Passwords: Exploiting the Human Factor

Thursday, March 8th, 2012

Attacking Wi-Fi passwords is near hopeless if a wireless hotspot is properly secured. Today’s wireless security algorithms such as WPA are using cryptographically sound encryption with long passwords. The standard enforces the use of passwords that are at least 8 characters long. Encryption used to protect wireless communications is tough and very slow to break. Brute-forcing WPA/WPA2 PSK passwords remains a hopeless enterprise even if a horde of GPU’s is employed. Which is, in general, good for security – but may as well inspire a false sense of security if a weak, easy to guess password is selected.

Elcomsoft Wireless Security Auditor is one tool to test how strong the company’s Wi-Fi passwords are. After checking the obvious vulnerabilities such as open wireless access points and the use of obsolete WEP encryption, system administrators  will use Wireless Security Auditor that tries to ‘guess’ passwords protecting the company’s wireless traffic. In previous versions, the guessing was limited to certain dictionary attacks with permutations. The new version gets smarter, employing most of the same guessing techniques that are likely to be used by an intruder.

Humans are the weakest link in wireless security. Selecting a weak, easy to guess password easily overcomes all the benefits provided by extensive security measures implemented in WPA/WPA2 protection. In many companies, employees are likely to choose simple, easy to remember passwords, thus compromising their entire corporate network.

The New Attacks
The new attacks help Elcomsoft Wireless Security Auditor recover weak passwords, revealing existing weaknesses and vulnerabilities in companies’ wireless network infrastructure.

Word Attack
If it’s known that a password consists of a certain word, the Word attack will attempt to recover that password by trying heavily modified versions of that word. This attack only has two options: you can set the source word and you can disable all permutations except changing the letter case. In addition, we can apply permutations to the source word first, forming a small dictionary; then perform a full dictionary attack, applying various permutations to all words from the newly formed list.

Mask Attack
Certain passwords or password ranges may be known. The mask attack allows creating a flexible mask, brute-forcing the resulting limited combination of passwords very quickly. The masks can be very flexible. One can specify placeholders for static characters, letter case, as well as full or limited range of special characters, digits or letters. Think of the Mask attack as an easy (and very flexible) way to check all obvious passwords from Password000 to Password999.

Combination Attack
You have two dictionaries. We combine each word from one dictionary with every word from another. By default, the words are combined as is, but you can increase the number of possible combinations by allowing delimiters (such as space, underscore and other signs), checking upper/lower case combinations or using extra mutations.

Hybrid Attack
This is one of the more interesting attacks out there. In a sense, Hybrid attacks come very close to how real human intruders think. The Hybrid attacks integrates ElcomSoft’s experience in dealing with password recovery. We’ve seen many (think thousands) weak passwords, and were able to generalize ways people are making them. Dates, names, dictionary words, phrases and simple character substitutions are the most common things folks do to make their passwords ‘hard to guess’. The new Hybrid attack will handle the ‘hard’ part.

Technically, the Hybrid attack uses one or more dictionaries with common words, and one or more .rul files specifying mutation rules. We’re supplying a few files with the most commonly used mutation rules:

Common.rul – integrates the most commonly used mutations. In a word, we’ve seen those types of passwords a lot, so we were able to generalize and derive these rules.
Dates.rul – pretty much what it says. Combines dictionary words with dates in various formats. This is a pretty common way to construct weak passwords.
L33t.rul – the “leet” lingo. Uses various combinations of ASCII characters to replace Latin letters. C001 hackers make super-strong passwords with these… It takes minutes to try them all.
Numbers.rul – mixes dictionary words with various number combinations.

Newer iOS Forensic Toolkit Acquires iPhones in 20 Minutes, Including iOS 5

Tuesday, November 1st, 2011

iOS 5 Support

When developing the iOS 5 compatible version of iOS Forensic Toolkit, we found the freshened encryption to be only tweaked up a bit, with the exception of keychain encryption. The encryption algorithm protecting keychain items such as Web site and email passwords has been changed completely. In addition, escrow keybag now becomes useless to a forensic specialist. Without knowing the original device passcode, escrow keys remain inaccessible even if they are physically available.

What does enhanced security mean for the user? With iOS 5, they are getting a bit more security. Their keychain items such as Web site, email and certain application passwords will remain secure even if their phone falls into the hands of a forensic specialist. That, of course, will only last till the moment investigators obtain the original device passcode, which is only a matter of time if a tool such as iOS Forensic Toolkit is used to recover one.

What does this mean for the forensics? Bad news first: without knowing or recovering the original device passcode, some of the keychain items will not be decryptable. These items include Web site passwords stored in Safari browser, email passwords, and some application passwords.

Now the good news: iOS Forensic Toolkit can still recover the original plain-text device passcode, and it is still possible to obtain escrow keys from any iTunes equipped computer the iOS device in question has been ever synced or connected to. Once the passcode is recovered, iOS Forensic Toolkit will decrypt everything from the keychain. If there’s no time to recover the passcode or escrow keys, the Toolkit will still do its best and decrypt some of the keychain items.

Faster Operation

Besides adding support for the latest iOS 5, Elcomsoft iOS Forensic Toolkit becomes 2 to 2.5 times faster to acquire iOS devices. When it required 40 to 60 minutes before, the new version will take only 20 minutes. For example, the updated iOS Forensic Toolkit can acquire a 16-Gb iPhone 4 in about 20 minutes, or a 32-Gb version in 40 minutes.

EPPB: Now Recovering BlackBerry Device Passwords

Thursday, September 29th, 2011

Less than a month ago, we updated our Elcomsoft Phone Password Breaker tool with the ability to recover master passwords for BlackBerry Password Keeper and BlackBerry Wallet. I have blogged about that and promised the “next big thing” for BlackBerry forensics to be coming soon. The day arrived.

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New version of EPPB: Recovering Master Passwords for BlackBerry Password Keeper and BlackBerry Wallet

Tuesday, August 30th, 2011

Conferences are good. When attending Mobile Forensics Conference this year (and demoing our iOS Forensic Toolkit), we received a lot of requests for tools aimed at BlackBerry forensics. Sorry guys, we can’t offer the solution for physical acquisition of BlackBerries (yet), but there is something new we can offer right now.

RIM BlackBerry smartphones have been deemed the most secure smartphones on the market for a long, long time. They indeed are quite secure devices, especially when it comes to extracting information from the device you have physical access to (i.e. mobile phone forensics). It is unfortunate, however, that a great deal of that acclaimed security is achieved by “security through obscurity”, i.e. by not disclosing in-depth technical information on security mechanisms and/or their implementation. The idea is to make it more difficult for third parties to analyze. Some of us here at Elcomsoft are BlackBerry owners ourselves, and we are not quite comfortable with unsubstantiated statements about our devices’ security and blurry “technical” documentation provided by RIM. So we dig. (more…)

Elcomsoft iOS Forensic Toolkit highlighted in SANS Information Security Reading Room

Monday, August 15th, 2011

SANS Information Security Reading Room has recently publicized a whitepaper about iOS security where they mentioned our software – Elcomsoft iOS Forensic Toolkit – in a section about encryption. Kiel Thomas, the author of the whitepaper, explained one more time the main principles of iOS 4 encryption, which became stronger in comparison with iOS 3.x and how our toolkit can bypass new strong algorithms.

In its next part about iTunes Backups Kiel touches upon Elcomsoft Phone Password Breaker which virtually crunches backup passwords at speed of 35000 passwords per second (with AMD Radeon HD 5970) using both brute force and dictionary attacks, here are some benchmarks.

It seems the paper does not miss out on any nuance about iOS 4 and provides practical advice to either avoid or prevent from the depressing outcomes, such as loss of data. Closer to the end of the paper you will also find several sagacious tips for using the devices within organizations, including passcode management, a so called “first line of defense” which according Kiel’s view “can be matched to existing password policies”, however he inclines to use passwords instead of 4 digit passcodes.

And in conclusion the author discovers that smartphone and tablet security measurements resemble the ones of laptops, because they all belong to mobile devices.  Find out more details in the source itself: http://www.sans.org/reading_room/whitepapers/pda/security-implications-ios_33724
 

Have you chosen you next smartphone? Why not BlackBerry? :)

Friday, May 20th, 2011

Despite the fact that iPhone and Android keep on biting off greater parts of smartphone market, BlackBerry fans are still there, in spite of its various peculiarities. I won’t compare multi-touch displays, HD cameras, smart sensors, applications or anything like that. I’d rather talk about BlackBerry Desktop Software.  Yes, it can create backups, restore information from backups, and synchronize with Outlook only, period.  But that’s just not enough… (more…)

Nikon Image Authentication System: Compromised

Thursday, April 28th, 2011
ElcomSoft Co. Ltd. researched Nikon’s Image Authentication System, a secure suite validating if an image has been altered since capture, and discovered a major flaw. The flaw allows anyone producing forged pictures that will successfully pass validation with Nikon’s Image Authentication Software. The weakness lies in the manner the secure image signing key is being handled in Nikon digital cameras.
 
The existence of the weakness allowed ElcomSoft to actually extract the original signing key from a Nikon camera. This, in turn, made it possible to produce manipulated images signed with a fully valid authentication signature.
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Cracking BlackBerry backups is now slower… but still possible, thx to GPU acceleration

Friday, December 24th, 2010

If you have read our recent Cracking BlackBerry Backup Passwords article, you should be familiar with encryption implemented in BlackBerry Desktop Software. Just reminding:

In short, standard key-derivation function, PBKDF2, is used in a very strange way, to say the least. Where Apple has used 2’000 iterations in iOS 3.x, and 10’000 iterations in iOS 4.x, BlackBerry uses only one.

So password verification is (was) so fast/simple that we did not care about implementing it on the GPU — modern CPU is able to crack almost 8 million passwords per second (thanks to multi-threading and AES-NI). We would not call that the vulnerability, but still the weak link.

But new versions of BlackBerry Desktop Software have been released reсently (6.0 for Windows and 2.0 for Mac). And as always, there are bad news and there are good news.
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BlackBerry password cracking: multi-threaded, with hardware-accelerated AES

Thursday, December 9th, 2010

Most modern CPUs are multi-core – it is not easy to find even a laptop with less than two cores these days. And for desktops, 4 cores are usual now.

Password recovery is one of most CPU-intensive tasks, and it fits best into multi-processor architecture. Every CPU (or CPU core) get its own portion of passwords to try (i.e. to check their validness), and they all work in parallel. As simple as that.

So what we’re doing in our software is running multiple threads – as many as the number of CPUs (or cores) available. And the rest is being done by the operating system, that assigns the threads to cores (well, in most cases we don’t care what particular core is going to execute a particular thread, because they are all equal; the only exception is when one or more of the cores is doing something already, I mean something CPU-intensive as well).

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Peeking Inside Keychain Secrets

Thursday, August 5th, 2010

Today we have released Elcomsoft iPhone Password Breaker 1.20 which introduces two new features and fixes few minor issues.

Keychain Explorer

This feature allows to view contents of keychain included with encrypted device backup.

Mac users are probably familiar with concept of keychain — it is a centralized, system-wide storage where application can store information they consider sensitive. Typically, such information includes passwords, encryption keys and certificates, but in principle it can be anything. Data in keychain is cryptographically protected by OS and user password is required to access it. The closest Windows equivalent for keychain is probably Data Protection API.

iOS-based devices also have a keychain, but instead of user password, embedded cryptographic key is used to protect its contents. This key is unique to each device and so far there are no way to reliably extract it from the device.

Apple recommends iOS application developers to use keychain for storing passwords and other sensitive information, and one reason for this is that it never leaves device unencrypted. Here’s an excerpt from Keychain Service Programming Guide:

In iOS, an application always has access to its own keychain items and does not have access to any other application’s items. The system generates its own password for the keychain, and stores the key on the device in such a way that it is not accessible to any application. When a user backs up iPhone data, the keychain data is backed up but the secrets in the keychain remain encrypted in the backup. The keychain password is not included in the backup. Therefore, passwords and other secrets stored in the keychain on the iPhone cannot be used by someone who gains access to an iPhone backup. For this reason, it is important to use the keychain on iPhone to store passwords and other data (such as cookies) that can be used to log into secure web sites.

Prior to iOS 4 keychain was also included in the backup ‘”as is”, i.e. all data inside was encrypted using unique device key. This meant that it was not possible to restore keychain onto another device — it will try to decrypt data with key which is different from one used to encrypt data. Naturally, this will fail and all data in keychain will be lost.

To address this issue, Apple changed the way keychain backup works in iOS 4. Now, if you’re creating encrypted backup (i.e. you’ve set up a password to protect backup) then keychain data will be re-encrypted using encryption key derived from backup password and thus ca be restored on another device (provided backup password, of course). If you haven’t set backup password, then everything works like before iOS 4 — keychain encrypted on device key is included in the backup.

Elcomsoft iPhone Password Breaker now allows you to view contents of keychain from encrypted backup of devices running iOS 4. You will need to provide password, of course. Here’s screenshot of Keychain Explorer showing (some) contents of my iPhone’s keychain:

Keychain Explorer 

There are passwords for all Wi-Fi hotspots I have ever joined (and haven’t pushed “Forget this Network” button), for my email, Twitter, and WordPress accounts, as well as Safari saved passwords and even my Lufthansa frequent flyer number and password! :) And I don’t use Facebook/LinkedIn/anything else on my phone — otherwise I guess credentials for those will be also included in the keychain.

Keychain Explorer will work only against backup which is encrypted. If you happen to have an iOS 4 device and want to get password from it — set a backup password in iTunes, backup device, use Keychain Explorer to view and/or export keychain passwords, and, finally, remove backup password in iTunes.

Password Cache

This feature is far less exciting than Keychain Explorer, but we believe it should improve user experience with Elcomsoft iPhone Password Breaker.

The idea is simple: all passwords which are found by EPPB or which are used to open backup in Keychain Explorer are stored in password cache. When you later try to open backup in Keychain Explorer or recover a backup password, program first checks password cache for correct password.

Passwords in cache are stored using secure encryption.

 

Also, there is a new EPPB FAQ online. Worth reading if you’re thinking of purchasing EPPB or want to learn more about it.

There is at least one really big update for EPPB coming in September or October, so stay tuned!