Category: White Papers

Nov 25 2014

CryptoPHP – Backdoor in Thousands of CMS Plugins and Themes Used to Hijack Web Servers

CryptoPHP BackdoorSecurity researchers have discovered thousands of backdoored plugins and themes for the popular content management systems (CMS) that could be used by attackers to compromise web servers on a large scale.

The Netherlands based security firm Fox IT has published a whitepaper revealing a new Backdoor named “CryptoPHP”. Security researchers have uncovered malicious plugins and themes for WordPress, Joomla and Drupal. However, there is a slight relief for Drupal users, as only themes are found to be infected from CryptoPHP backdoor.

In order to victimize site administrators, miscreants makes use of a simple social engineering trick. They often lured site admins to download pirated versions of commercial CMS plugins and themes for free. Once downloaded, the malicious theme or plugin included backdoor installed on the admins’ server.

By publishing pirated themes and plug-ins free for anyone to use instead of having to pay for them, the CryptoPHP actor is social-engineering site administrators into installing the included backdoor on their server“, Fox IT said in its analysis on the attack.

Once installed on a web server, the backdoor can be controlled by cyber criminals using various options such as command and control server (C&C) communication, email communication and manual control as well.

Other capabilities of the CryptoPHP backdoor include:

  • Integration into popular content management systems like WordPress, Drupal and Joomla
  • Public key encryption for communication between the compromised server and the command and control (C2) server
  • An extensive infrastructure in terms of C2 domains and IP’s
  • Backup mechanisms in place against C2 domain takedowns in the form of email communication
  • Manual control of the backdoor besides the C2 communication
  • Remote updating of the list of C2 servers
  • Ability to update itself

Miscreants are using CryptoPHP backdoor on compromised Web sites and Web servers for illegal Search Engine Optimization (SEO), which is also known as Black Hat SEO, researchers said in its report. It is because the compromised websites link to the websites of the attackers appear higher in search engine results.

Black Hat SEO is a group of techniques and tactics that focus on maximizing search engine results with non-human interaction with the pages, thus violating search engine guidelines. These include keyword stuffing, invisible text, doorway pages, adding unrelated keywords to the page content or page swapping.

The security company has discovered 16 variants of CryptoPHP Backdoor on thousands of of backdoored plugins and themes as of 12th November 2014. First version of the backdoor was appeared on the 25th of September 2013. The exact number of websites affected by the backdoor is undetermined, but the company estimates that at least a few thousand websites or possibly more are compromised.

Dec 25 2013

4096-bit RSA Key Extraction Attack via Acoustic Cryptanalysis

A trio of scientists have verified that results they first presented nearly 10 years ago are in fact valid, proving that they can extract a 4096-bit RSA key from a laptop using an acoustic side-channel attack that enables them to record the noise coming from the laptop during decryption, using a smartphone placed nearby. The attack, laid out in a new paper, can be used to reveal a large RSA key in less than an hour.

Acoustic Cryptanalysis
Parabolic microphone extracting an RSA key from a target laptop

The attack relies on a number of factors, including proximity to the machine performing the decryption operation and being able to develop chosen ciphertexts that incite certain observable numerical cancellations in the GnuPG algorithm. Over several thousand repetitions of the algorithm’s operation, the researchers discovered that there was sound leakage they could record over the course of fractions of a second and interpret, resulting in the discovery of the RSA key in use.

Their attack works against a number of laptop models and they said that there are a number of ways that they could implement it, including through a malicious smartphone app running on a device near a target machine. They could also implement it through software on a compromised mobile device of through the kind of eavesdropping bugs used by intelligence agencies and private investigators.

The developers of GnuPG have developed a patch for the vulnerability that the Israeli researchers used, implementing a technique known as blinding. The patch is included in version 1.4.16 of GnuPG. Shamir and his co-authors, Daniel Genkin and Eran Tromer, said that they also could perform their attack from a greater distance using a parabolic microphone and may also work with a laser microphone or vibrometer.

Research Paper: RSA Key Extraction via Low-Bandwidth Acoustic Cryptanalysis

Sep 10 2013

Report : PHP SuperGlobals are Vulnerable to Hackers

PHP SuperGlobals VulnerabilityIn the most recent Hacker Intelligence Initiative Report – “PHP SuperGlobals: Supersized Trouble“, Imperva analyses vulnerabilities found in the SuperGlobal parameters of the PHP platform, and finds that a multi-step attack requires a multi-layered application security solution.

In addition to local and global scope variables, PHP has several predefined variables that are called SuperGlobals. These variables are available to the PHP script in both scopes, with no need for explicit declaration. 4 SuperGlobals were introduced to PHP in version 4.1.0.

The PHP SuperGlobal parameters are gaining popularity within the hacking community because they incorporate multiple security problems into an advanced web threat that can break application logic, compromise servers, and result in fraudulent transactions and data theft.

In one month, Imperva’s research team noted an average of 144 attacks per application that contained attack vectors related to SuperGlobal parameters. Furthermore, researchers witnessed attack campaigns lasting more than five months with request burst floods of up to 90 hits per minute on a single application.

The effects of these attacks can be great as the PHP platform is by far the most popular web application development platform, powering more than 80 percent of all websites, including Facebook and Wikipedia. Clearly, it is time for the security community to devote more attention to this issue.

The report also finds that hackers are increasingly capable of packaging higher levels of sophistication into simpler scripts, and identifies PHP SuperGlobals as a prime target that yields a high return on investment.

“Exploits Against PHP Applications Can Affect the General Security and Health of the World Wide Web”.

Jun 26 2012

Crack RSA SecurID 800 Secret Key in 13 Minutes

RSA SecurID 800RSA’s SecurID 800 is one of at least five commercially available security devices susceptible to a new attack that extracts cryptographic keys used to log in to sensitive corporate and government networks.

Scientists have devised an attack that takes only minutes to steal the sensitive cryptographic keys stored on a raft of hardened security devices that corporations and government organizations use to access networks, encrypt hard drives, and digitally sign e-mails.

The exploit, described in a paper to be presented at the CRYPTO 2012 conference in August, requires just 13 minutes to extract a secret key from RSA’s SecurID 800, which company marketers hold out as a secure way for employees to store credentials needed to access confidential virtual private networks, corporate domains, and other sensitive environments. The attack also works against other widely used devices, including the electronic identification cards the government of Estonia requires all citizens 15 years or older to carry, as well as tokens made by a variety of other companies.

“They’re designed specifically to deal with the case where somebody gets physical access to it or takes control of a computer that has access to it, and they’re still supposed to hang onto their secrets and be secure,” Matthew Green, a professor specializing in cryptography in the computer science department at Johns Hopkins University, told Ars. “Here, if the malware is very smart, it can actually extract the keys out of the token. That’s why it’s dangerous.” Green has blogged about the attack here.

It’s this version of the attack the scientists used to extract secret keys stored on RSA’s SecurID 800 and many other devices that use PKCS#11, a programming interface included in a wide variety of commercial cryptographic devices. Under the attack Bleichenbacher devised, it took attackers about 215,000 oracle calls on average to pierce a 1024-bit cryptographic wrapper. That required enough overhead to prevent the attack from posing a practical threat against such devices. By modifying the algorithm used in the original attack, the revised method reduced the number of calls to just 9,400, requiring only about 13 minutes of queries, Green said.

Other devices that store RSA keys that are vulnerable to the same attack include the Aladdin eTokenPro and iKey 2032 made by SafeNet, the CyberFlex manufactured by Gemalto, and Siemens’ CardOS, according to the paper.

Dec 22 2011

Backdoor in Android for No-Permissions Reverse Shell

Security expert Thomas Cannon working at viaForensics as the Director of R&D has demonstrated a custom-developed app that installs a backdoor in Android smartphones – without requiring any permissions or exploiting any security holes.

Thomas built an app which requires no permissions and yet is able to give an attacker a remote shell and allow them to execute commands on the device remotely from anywhere in the world. The functionality they are exploiting to do this is not new, it has been quietly pointed out for a number of years, and was explained in depth at Defcon-18 Presentation.

It is not a zero-day exploit or a root exploit. They are using Android the way it was designed to work, but in a clever way in order to establish a 2-way communication channel. This has been tested on Android versions ranging from 1.5 up to 4.0 Ice Cream Sandwich, and it works in a similar way on all platforms.

The application operates by instructing the browser to access a particular web page with specific parameters. This web page, and the server behind it, will, in turn, control the app by forwarding the browser to a URL that starts with a protocol prefix that is registered as being handled by the app, for example app://. This process can then be repeated and in doing so it enables two-way communication.

“In this demonstration Android’s power and flexibility were perhaps also its downfall. Other smartphone platforms may not offer the controls we are bypassing at all, and the multi-tasking capabilities in Android allowed us to run the attack almost transparently to the user. This power combined with the open nature of Android also facilitates the customisation of the system to meet bespoke security requirements. This is something we have even been involved in ourselves by implementing a proof of concept Loadable Kernel Module to pro-actively monitor and defend a client’s intellectual property as it passed through their devices. It is no surprise that we have seen adoption of Android research projects in the military and government as it can be enhanced and adapted for specific security requirements, perhaps like no other mobile platform before it.”Thomas Cannon said